bluuebunny/crossref_metadata_2025 huggingface dataset:
Introduction
Authors: Bicknell Roy , Lewis Claire E , Ferrara Napoleone
Published: November 2023

There are two recognized mechanisms by which blood vessels arise that are termed vasculogenesis and angiogenesis. Angiogenesis describes the development of new vessels from existing vessels. The process has been long known; indeed it was certainly recognized as early as 1787 when John Hunter noted that it occurred during the development of reindeer antlers (1). The purpose of this introduction is not to provide a detailed history of the field but to set the scene for the chapters that follow. This book is intended to give a comprehensive review of the state of our current understanding of the field primarily, but not exclusively, in relation to tumour angiogenesis. Each chapter has been written by an acknowledged expert in a specific area. The reason that the volume concentrates on tumour angiogenesis is because studies in this area have dominated the field of angiogenesis over the past 20 years. This is due in part to the work of Petro Gullino at the National Cancer Institute in Frederick and later Judah Folkman at Harvard Medical School. Both have been instrumental in bringing the concept of tumour angiogenesis and its inhibition as a potential anti-cancer therapeutic strategy to the attention of a wide cross-section of the research community. Nevertheless, the contents of the book are of relevance to all researchers interested in blood vessel development, particularly the chapters covering the role of individual cytokines.
In vivo models of angiogenesis
Authors: Fan TaiPing D , Polverini Peter F
Published: November 2023

To discover and test the efficacy of new anti-angiogenics, it is imperative to have appropriate in vivo models. The classical assays for angiogenesis include the hamster cheek pouch (l-4), rabbit ear chamber (5), dorsal skin and air sac (6-8), the chick chorioallantoic membrane (CAM) (8-10), and iris and avascular cornea of rodent eye (11-13). The past 10 years have seen improvements of some of these assays and the introduction of several new models, e.g. subcutaneous implantation of plastic chambers (14) or porous polytetrafluoroethylene tubes (15). In particular, techniques involving the subcutaneous implantation of sterile sponges into experimental animals have become popular (16-18). Furthermore, a variety of naturally occurring and chemically modified versions of matrices such as Matrigel (19,20) or fibrin gels (14) that were only used until recently to analyse angiogenesis in vitro.
The role of macrophages in tumour angiogenesis
Authors: Leek Russell D , Lewis Claire E , Harris Adrian L
Published: November 2023

Solid tumours do not consist of neoplastic cells in isolation, rather, they comprise of a range of cellular types, which often outnumber the tumour cell population (1,2). The tumour cells are usually surrounded by a supportive stroma consisting of a fibrous extracellular matrix (ECM) laid down by fibroblasts. Insinuating into this environment are blood vessel endothelial cells, which provide nutritional and respiratory support for the tumour. Often, there is also an infiltrate of inflammatory cells such as lymphocytes, natural killer cells, neutrophils, and macrophages. These cells communicate by a complex network of intercellular signalling pathways mediated by surface adhesion molecules and soluble polypeptides called cytokines and their receptors (3,4).
Pleiotrophin and related molecules
Authors: Schulte Anke M , Wellstein Anton
Published: November 2023

A number of polypeptide growth factors have marked affinity for the glycosaminoglycan heparin and for heparan sulphates found on cell surfaces and in the extracellular matrix (ECM). These growth factors are collectively called heparin-binding growth factors (HBGFs) and comprise distinct polypeptides such as the vascular endothelial cell growth factor (VEGF), and fibroblast growth factors (FGF) (reviewed in chapters 16, 17). FGFs are the largest group of known HBGFs comprising at least 10 different members ( l) and they were the first growth factors for which heparin affinity was demonstrated (2). Several years ago a novel gene family of HBGFs was discovered that appeared biologically very closely related to FGFs but turned out to be structurally distinct from FGFs as well as from any other known growth factors. The two members of this family are pleiotrophin (PTN) and midkine (MK). They are secreted HBGFs with an apparent molecular mass of 18 and 14 kDa, respectively, and they are highly conserved between different species as well as between each other; e.g. the secreted portion of the human and bovine PTN protein differ by only one amino acid, and the homology between the PTN and MK proteins is on average close to 50% taking conservative amino acid replacements into account. Both proteins were original described as developmentally regulated cytokines based on their expression pattern during fetal and neonatal brain development. In addition to this, PTN as well as MK appear to participate in tumour growth and angiogenesis.
Inhibition of tumour angiogenesis and the induction of tumour dormancy
Authors: Holmgren Lars , Bicknell Roy
Published: November 2023

Since the early 1970s when Folkman popularized the idea that tumour growth is angiogenesis-dependent and that an anti-angiogenic strategy might constitute a novel therapeutic approach for the treatment of solid tumours (1) there has been an ever increasing interest in the idea. Indeed, with the realization that anti-angiogenesis may be useful in the treatment of a number of pathologies aside from cancer (e.g. psoriasis, diabetic retinopathy, menorrhagia, etc.) over the last 10 years interest in the identification of a therapeutically useful anti-angiogenic compound has become intense.
Development of the embryonic vascular system
Authors: Young Paul E , Lasky Laurence A
Published: November 2023

The Establishment of the vascular system is a critical step in the development of the vertebrate embryo. Numerous mutations and gene knockouts that indirectly compromise the ability of the mammalian embryo to establish and maintain an embryonic and/or yolk sac vasculature frequently result in early embryonic lethality (for review, see reference I). As the embryo develops bulk and the various organ primordia appear and become organized, it is essential that all cells within a tissue mass receive an adequate supply of oxygen and nutrients and an efficient means of clearing waste products.
The open seas
Authors: Fogg G E
Published: November 2023

The ice-free areas of the polar seas do not differ in any fundamental way from the temperate seas with which they are confluent. They are colder and more tempestuous but these are only matters of degree and, although there are special features of hydrography, so there are in every other sea. Nevertheless, there are good reasons for including them as polar habitats. They interact with ice and the polar atmosphere, play important roles in polar thermal regimes (p. 8), and provide the organic production which sustains the animal life of both Arctic and Antarctic coastal regions. In detail they have their own biological characteristics. Study of polar marine biology has lagged behind that in other sea areas but it is evident that the Arctic seas and the Southern Ocean play crucial parts in global processes and that knowledge of their biological, as well as physical, oceanography is essential if we are to understand and manage our environment. The hydrographical and physical background has already been outlined (p. 8) and this chapter is concerned with the ecology.
Feeling and Hearing
Authors: Herring Peter
Published: November 2023

A night-time walk in a dark wood (where our visual sense temporarily fails) provides a reminder of the information our various mechanoreceptors can give us about the environment and its inhabitants. The distant rumble of thunder, a breath of wind, the brush of a moth, the squeal of a captured mouse, the squeak of a bat, or the hoot of an owl, each adds to our knowledge of the surroundings even though both our perceptions and our interpretations are inevitably limited.
Feral populations of Xenopusoutside Africa
Authors: Tinsley FI C , Mccoid M J
Published: November 2023

Although now limited naturally to Africa south of the Sahara, the clawed frogs actually have the capacity for a wide geographical distribution. During the past 30 years or more, Xenopus has been introduced into a range of temperate regions, in North and South America, Europe and some isolated localities such as Ascension Island. All these intro¬ ductions appear to have been of one species, Xenopus laevis from the Cape, South Africa. A critical review shows that many reports have not been substantiated recently. Our data are based on populations in the USA and the UK. Long-term records of colonies in the UK, where X. laevis are individually dye-marked for recapture studies, show relatively mobile and long-lived individuals, some being caught regularly for up to nine years.
Energy and nutrients
Authors: Giller Paul S , Malmqvist Björn
Published: November 2023

So far we have examined the nature of the running water habitat and the organisms and their adaptations. we now turn to the population, community, and ecosystem levels and in the next three chapters explore the various patterns and processes that are found in streams and rivers. Flowing water and the intimate link between the stream and its valley leads to some of the unique structural and functional features of the lotic system. To set the scene, we will explore the processes involving energy, nutrients, and decomposition in this chapter before turning to movement, colonization, and species interactions in Chapter 7, and then discuss community structure, species diversity and distribution at the biogeographic scale in Chapter 8.
The use, abuse, and conservation of running waters
Authors: Giller Paul S , Malmqvist Björn
Published: November 2023

Rivers all over the world have supported the growth of human civilization since the first towns appeared some 7000 years ago ( meybeck, 1996) but as a result of this growth and the diversification of activities, most of the world’s rivers have been negatively affected. Nearly thirty years ago, H.B.N. Hynes (1970) wrote’... human activity has profoundly affected rivers and streams in all parts of the world to such an extent that it is now extremely difficult to find any stream which has not been in some way altered and probably quite impossible to find any such river’. The situation has not improved to any great extent to the present day and has, if anything, deteriorated further in many parts of the world. What has improved is our understanding of the changes we have wrought, the factors causing them and to some small degree, how we can prevent future impacts and start rehabilitating damaged systems.
Reproductive strategies and sperm competition in the adder, Vipera berus
Authors: Andren Claes , Nilson Goran , Hoggren Mats , Tegelstrom Ihakan
Published: November 2023

Reproduction in temperate snakes shows large variation. In males the reproductive cycle is annual, while females have a biennial or longer cycle depending on species and environmental conditions. Ovulation (fertilization) is temporally separated from copulation, allowing sperm competition in polyandric species. This system can, however, be violated by male-mediated renal sex secretion reducing sperm transfer from later matings by contraction of posterior uteri, or by a copulatory plug. Matings can be restricted to one spring or autumn period or can be biannual. Short-term sperm storage between mating and ovulation is the normal case, but sperm can be stored over winter in species with autumn matings, or several years in species lacking aggregation periods or with low population density. In the adder (Vipera berus), precopulatory behaviour in spring includes violent male-male combats and mate guarding, and sex ratio is male-biased because the female reproductive cycle is biennial. During recent years quite different opinions have been expressed concerning adder reproductive behaviour. Main questions have involved the presence or importance of long-term sperm storage, a copulatory plug, multiple paternity in wild populations, male and female choice and whether promiscuity influences offspring viability. We performed DNA fingerprinting of 12 litters of adders in order to find out whether multiple paternity can be determined without collecting fathers and in order to investigate the significance of multiple paternity in wild adders. For each litter we tested the binomial probability that a single father would transmit the observed number of paternal bands in each offspring. In 83% of the litters only one male had sired the offspring, while in the remaining litters more than one father was involved. We conclude that although females may copulate more than once with a single male, multiple paternity is a rare event in the population studied.
Geographical and intraspecies variation in the clinical manifestations of envenoming by snakes
Authors: Warrell David A
Published: November 2023

The range and severity of clinical manifestations after a bite by a particular species of snake and hence the prognosis depend on the quantity of venom injected, its composition, the site and depth of the bite, the age and previous health of the victim and the quality of first aid and medical treatment. The quantity and composition of venom will vary with the age/size of the snake, the mechanical efficiency of the bite and the amount of venom present in the venom apparatus immediately before the strike. Variation in venom composition and antigeniciity throughout the geographical range of a single ‘species ‘ has been documented and, even at a particular geographical locus, composition of venom from individual snakes of the same age/size may not be homogeneous. All these sources of variation make it difficult to predict the outcome of a bite and to provide guidelines for clinical management, even if the species is known. Optimal medical treatment depends on the precise identification of the biting species. Ideally, this will be based on examination of the snake responsible for the bite or on rapid identification of specific venom antigen in the patient ‘s serum or other body fluids, for example by enzyme immunoassay. Failing that, the clinician must decide on the most likely species, based on the circumstances of the bite, the patient ‘s description of the appearance and behaviour of the snake and the symptoms and signs of envenoming. For antivenom production, use of a pool of venom from correctly identified snakes of different ages/sizes and geographical origins is essential in view of the intraspeciies variation in venom composition and antigenicity.
Photosymbiosis: access to a new metabolic capability
Authors: Wood Rachel
Published: November 2023

All reefs are sites of increased carbonate production, but few are significant beyond a local scale. Of these, coral reefs are of global importance, scattered over some 584-746 x 103 square kilometres in modern tropical seas (Kleypas 1997).
Superconducting Materials
Authors: Etourneau J
Published: November 2023

In 1908 the experiments of Kammerlingh-Onnes1 on the liquefaction of helium led to the study of a number of phenomena in the temperature range 1 K to 14 K. One of the first experiments that he performed was the measurement of the resistivity of numerous materials as a function of temperature. Thus he found (1911) that the electrical resistance of a purified mercury sample dropped sharply from 0.08 Q at above 4 K to less than 3 x 10-6 Q at about 4.2 K. This drop occurred over a temperature interval of0.01 K (Fig. 3.1). This phenomenon was called superconductivity. The most striking feature of all superconducting materials is that below a critical temperature, labelled T  cr, the electrical resistance is zero.
Intercalation Reactions of Layered Compounds
Authors: Jacobson Allan J
Published: November 2023

Intercalation reactions are reactions of solids in which a guest molecule or ion is inserted into a solid lattice without major rearrangement of the solid structure. Unlike normal solid state processes, intercalation reactions do not involve extensive bond breaking and consequently require special chemical and structural features in order to occur. In particular, intercalation requires that the host lattice has a strong covalent network of atoms which remains unchanged on reaction and that there are vacant sites in the structure which are interconnected and of suitable size to permit diffusion of the guest species into the solid. Reactions may occur near ambient temperature but, in general, the reaction temperature needs to be sufficiently high to ensure reasonable diffusivities of the guest molecules or ions, but not so high that rearrangements of the strong bonds in the structure occur. The requirement that part of the solid structure remains unchanged on reaction implies that intercalation compounds will often be metastable phases.
Atoms In Chemistry
Authors: Bader Richard F W
Published: November 2023

Chemistry is the study of the properties of substances and their transformations. Since substances are identified and distinguished one from another by the elements they contain and since the properties of each element are determined by the atoms unique to that element, chemistry is the study of matter at the atomic level. The realization of this fact by Dalton in 1807 marked the birth of chemistry as a branch of science. Dalton’s atomic hypothesis accounted for the existence of the observed relative combining weights of the elements and predicted a new relationship among them, the law of multiple proportions. Dalton did not simply resurrect the Greek idea of atoms; he postulated that atoms retained their identity even when in chemical combination with other atoms—that atoms exist in molecules. As a result of the work of van’t Hoff and Le Bel in 1874 the geometrical aspect of molecular structure was incorporated into the hypothesis by postulating the existence of preferred geometrical arrangements of bonds terminating at a single atom. Before the close of his century, there had evolved from Dalton’s atomic hypothesis the concept of molecular structure—that a molecule is a collection of atoms linked by a network of bonds, the bonds imparting the structure.
Calixarene chemistry: an overview
Authors: David Gutsche C
Published: November 2023

The chemistry of the calixarenes is abundantly described in a pair of current books1 as well as in chapters in several recent books devoted to macrocyclic systems.2 Rather than adding another detailed essay to this group of pub lished works, the present chapter provides a more qualitative overview of the field. Readers interested in fuller and more quantitative accounts should consult one or another of the sources cited in references 1 and 2.
Structural aspects of organic clathrates in relation to molecular recognition
Authors: Goldberg Israel
Published: November 2023

Research activity in the field of clathrate inclusion chemistry has increased remarkably in recent years. New approaches to the systematic design of novel clathrate-forming host compounds have been reported, those leading to selective interaction between hosts and different classes of guest molecule attracting particular attention. In fact, a large number of successful applications to molecular separation processes which are based on clathrate formation are already known, and many others are anticipated in the near future. This continuously growing excitement has been documented in many original papers and proceedings of international conferences as well as in several review articles.
The Meaning of Quantum Theory
Authors: Baggott Jim
Published: November 2023

In this book the author looks at the continuing debate about the meaning of quantum theory. The historical development of the theory is traced from the turn of the century through to the 1930’s, and the famous debate between Niels Bohr and Albert Einstein. The book examines in detail the arguments that quantum theory is incomplete, as made by Einstein, Boris Podolsky, and Nathan Rosen; the development of Bell's theorem; and crucial experimental tests performed in the early 1980’s. Alternative interpretations - pilot waves, quantum gravity, consciousness, many worlds, and God - are described in the closing chapter. This book is aimed at graduate and senior undergraduate students of physics and chemistry taking quantum chemistry or quantum theory courses, and other scientists interested in the subject.
What does it mean?
Authors: Baggott Jim
Published: November 2023

The strange behaviour of photons described at the end of the last chapter immediately raises all sorts of questions about the meaning of quantum theory. We might be encouraged to look for this meaning by going back to the theory’s mathematical structure: perhaps by trying to find out how we might better interpret some of its elements. However, it is a central argument of this book that, no matter where we look, we are always led back to philosophy. At first sight, this might seem to be an odd thing to claim. After all, modern textbooks on quantum physics and chemistry rarely (if ever) discuss philosophy. We accept that the behaviour of photons is strange, but surely it is something that we can at least study experimentally-do we need philosophy in these circumstances? But this is the whole point. Quantum theory directly challenges our understanding of the nature of the fundamental particles and the process of measurement, and we cannot go forward unless we adopt some kind of interpretation. As we will see, this interpretation has to be based on some philosophical position.
Unusual subvalent compounds of germanium, tin, and lead
Authors: Lappert Michael F
Published: November 2023

Thermally stable heavy main Group 14 element analogues of carbenes of type MX (M = Si, Ge, Sn, or Pb) are now widely known (except for Si). For MX, the group X, if monodentate, must be bulky so that oligo- or polymerization is avoided. In 1976 we showed that for the case of X = R = CH(SiMe)z the tin compound existed as a metal-metal bonded dimer (RSn)z. More details were published in 1986, when the structure of the analogous germanium compound (R Geh was revealed and MO calculations were presented.
Selective synthesis of biologically active amino alcohols via allylic tin compounds
Authors: Yamamoto Y oshinori
Published: November 2023

The Lewis acid-mediated reaction of acyliminium ions with -y-oxygensubstituted allyltin compounds affords the amino alcohol in good yields. High diastereoselectivity is realized in some reactions, and the procedure can be applied to the synthesis of (±)-statine. The a- or the -y-amino acid derivatives can be prepared with high regioselectivity from diethylazo dicarboxylate and tin- or germanium-masked dienolates.
Effects of two triorganotin(IV) compounds on rubberwood biodeterioration
Authors: Kuthubutheen A J , Salahudin Y , Das V G Kumar
Published: November 2023

Rubberwood stakes impregnated separately with two tributyltin compounds, tributyltin N,N-dimethyldithiocarbamylacetate (TDTC) and tributyltin methanesulphonate (TBMS), were used in exposure trials above, on and below the ground in a forest environment over a period of twelve months. The loss in dry weight of the stakes impregnated with TDTC and TBMS was found to be, respectively, 35 and 75 per cent that of the untreated control stakes. The weight Joss of the TDTC-treated stakes was considerably retarded during the first six months of exposure whereas for the control stakes, the bulk of weight Joss occurred during this period. No decrease in the C: N ratio was apparent for the TDTC-treated stakes that were exposed above ground during the twelve months whereas the C:N ratio of the untreated stakes was reduced by as much as 23 percent.
Oxide and nitrided oxide grown on silicon at low temperature
Authors: Daud Alias , Hirose Masataka
Published: November 2023

An efficient low-temperature technique is necessary in the fabrication of sub-micron VLSI devices in order to minimize problems such as substrate webpage, dopant redistribution, and defect generation that are associated with conventional high-temperature techniques. The oxidation of silicon to thin silicon dioxide films is presently carried out at temperatures around 1000°C. The oxidation rate under a dry oxygen atmosphere is extremely low at temperatures below 800°C, however, and the resulting silicon-silicon dioxide interfaces are unsuitable for practical applications. Nitridation techniques have been extensively developed, and insulating films possessing high resistance against alkali-metal ion migration, dielectric-breakdown strength, and radiation hardness have been prepared.
Quantum chemistry
Authors: Laidler Keith J
Published: November 2023

By the beginning of the twentieth century most scientists were satisfied that their basic problems were solved, all that remained being to fill in a few details. The principles of mechanics had been well worked out, heat was understood to be a mode of motion, and light to have wave properties. Some difficulties did, of course, remain, and were referred to in a lecture given by Lord Kelvin at the Royal Institution on 27 April 1900:The beauty and clearness of the dynamical theory, which asserts heat and light to be modes of motion, is at present obscured by two clouds. I. The first ... involves the question, How could the earth move through an elastic solid, such as essentially is the aluminiferous ether? II. The second is the Maxwell– Boltzmann doctrine of partition of energy.In referring to the partition of energy Kelvin had in mind the problem of interpreting the specific heats of gases and of solids. Here the belief in the equipartition of energy, which Maxwell and Boltzmann seemed to have estab¬lished beyond any doubt, was leading to the wrong answers (Section 5.3). Another difficulty, not mentioned here by Kelvin, was the interpretation of the spectra of atoms and molecules. The fact that spectral lines appear only at particular wavelengths had never been given an adequate explanation; some of the ideas put forward were mentioned in Section 6.5, and they were obviously inadequate.
Polymer Phase Diagrams
Authors: Koningsveld R , Stockmayer W H , Nies E
Published: November 2023

Polymeric materials include plastics, gels, synthetic fibres, and rubbers. They are all-important both in industry and in daily life. Unlike liquid water, ice, or sugar solution, polymers are not homogeneous. They are said to consist of two or more phases, and their production and processing, as well as their properties and uses, depend on an understanding of the transitions that take place between these phases. Over the last two decades, phase diagrams of considerably complexity have begun to appear in the polymer literature. Phase transitions occur abundantly in polymer production and processing, are often encountered in poymer research, or are instrumental in laboratory methods of polymer characterization. This new textbook uses fundamental principles to classify phase separation phenomena in polymer systems, and describes simple molecular models explaining the observed behaviour. It supplies insight in the reading and construction of complex phase diagrams, as well as an understanding of the relationships that must exist between different phase transitions. Containing hundreds of diagrams, exercises at chapter ends, and several useful appendices, this text should be useful for anyone teaching or studying a course in polymer science.
Single-component systems
Authors: Koningsveld R , Stockmayer W H , Nies E
Published: November 2023

The fundamental laws of classical equilibrium thermodynamics are briefly recalled here. We assume that the reader has already encountered these and has access to one or more standard textbooks of thermodynamics. Recommendations for general reading are indicated in the list of references.
Modelling partial miscibility and solid/liquid equilibrium
Authors: Koningsveld R , Stockmayer W H , Nies E
Published: November 2023

Although the basic thermodynamic principles of phase equilibrium have been known for over a century, comprehensive phase diagrams like that of Bakhuis Roozeboom are still not known in detail for many systems. If data are available over limited ranges of the state variables, extrapolations based on the appropriate thermodynamic equations, as presented in the foregoing chapters, may be used to extend the range and predictive power of such diagrams. In general, the reliability of such extrapolations may be rather low, but it can be greatly enhanced with the aid of suitable molecular models. In this text we cannot offer a complete description of such models, but we shall describe some of the simplest approaches which are useful in at least a semi-quantitative way. Details of such calculations are shown for a few examples in Appendix 2.
α-Amino- protection
Authors: Jones John
Published: November 2023

If an α-amino group is to be ‘stabilized’ in the context of peptide synthesis, its nucleophilic reactivity must be suppressed, by draining its electron density away into an appropriate substituent, or by concealing it altogether behind a screen of gross st eric hindrance.
Thermal dissociation reactions
Authors: Mukaiyama Teruaki
Published: November 2023

When a urea is heated in an aqueous alkaline solution, dissociation occurs to give an amine and an isocyanine; the isocyanine further reacts with water to decompose into an amine and carbon dioxide, as shown in eqn (1.1)-(1.3). My first project was to investigate the mechanism of this dissociation reaction. While trying to devise a method to measure the rate of the dissociation, we found that when this reaction was carried out in carboxylic acid as solvent, the isocyanine reacted immediately with the carboxylic acid to give a carboxylic amide along with the evolution of carbon dioxide. Therefore, we decided to follow the dissociation reaction by measuring the amount of carbon dioxide that had evolved from the reaction. The equipment necessary for this experiment was simply a constant-temperature bath, a gas burette, and a stop-watch.
New synthetic reactions based on organosulfur compounds
Authors: Mukaiyama Teruaki
Published: November 2023

In previous chapters, we have discussed the deoxygenation reaction, the new type of ring-opening polymerization, and the dehydrative condensation via oxidation--reduction process. These reactions have been developed based on the consideration that trivalent phosphorus compounds are readily oxidized into pentavalent phosphorus compounds, with simul-taneous reduction of organic compounds.
The stereoselective synthesis of carbohydrate0073
Authors: Mukaiyama Teruaki
Published: November 2023

In the previous chapter, our work in the area of asymmetric synthesis was described, where the concept of ‘synthetic control’ served to realize the regulation of absolute stereochemistry in organic reactions. In this chapter, an account of our efforts to achieve control over relative stereochemistry in organic reactions will be given, aimed at the synthesis of carbohydrates. My interest in carbohydrates had been initiated while working on glycosylation reactions using the onium salts of aza-aromatics. A new research programme does not suddenly come about without any experience in that topic. It is often suggested strongly by the facts observed during previous experiments.
Experimental Systems 2: Gas-Phase Reactions
Authors: Gray Peter , Scott Stephen K
Published: November 2023

Although solution-phase reactions have been more extensively studied, and certainly more widely publicized, a number of spontaneous reactions in the gas phase also provide exemplary oscillators. Here we look at three of the simplest oxidation processes: those of hydrogen, of carbon monoxide, and of acetaldehyde (ethanal). After careful study of this chapter the reader should be able to.
Two-Dimensional Correlation Methods Based on Coherence Transfer
Authors: Ernst Richard R , Bodenhausen Geoffrey , Wokaun Alexander
Published: November 2023

The interpretation of NMR spectra of networks of coupled spins requires some way of establishing the connectivity of nuclear spins.
Phenomenology of Rarefied Gas Flows
Authors: Mccourt Frederick R W , Beenakker Jan J M , Kohler Walter E , Kuscer Ivan
Published: November 2023

Until now we have been concerned only with phenomena in a dilute gas, which means that we have neglected all effects of boundaries and boundary layers.
Surface Scattering
Authors: Mccourt Frederick R W , Beenakker Jan J M , Kohler Walter E , Kuscer Ivan
Published: November 2023

The wall of the vessel containing a gas imposes upon the solution of the Boltzmann equation a boundary condition which relates the outgoing and incoming parts of the distribution function.
Mathematical Appendices
Authors: Mccourt Frederick R W , Beenakker Jan J M , Kohler Walter E , Kuscer Ivan
Published: November 2023

This chapter contains much of the mathematical material which is used periodically throughout the earlier chapters. We have gathered it together in one chapter, rather than spread it throughout the book as appendices to the individual chapters.
Chemical Chaos
Authors: Scott Stephen K
Published: November 2023

Chaos theory challenges fundamental ideas in all areas of science, and many of the best examples arise in chemistry. Reactions can become unrepeatable and unpredictable, even though they remain governed by traditional rate equations. Despite the complex appearance of the overall behaviour, the underlying mechanisms are quite simple, and the basic building blocks for chaos - nonlinearity and feedback - both occur quite naturally in chemical systems. Chaos does not appear suddenly or at random, but is created through one of a small number of highly ordered sequences of increasing complexity. These sequences are comprised of qualitative changes in behaviour or `bifurcations'. This valuable account of chemical chaos reviews both theory and experiment, emphasising the simple features that combine to produce `order within disorder'. The author begins by revealing the links between chemical kinetics and the interdisciplinary subject of dynamical systems. Various bifurcation sequences are then introduced through representative model schemes, with the emphasis on generality and simplicity. Chaos arises in both conventional chemical reactions and forced or coupled systems, and both are considered here. Various experimental and diagnostic techniques to test for chaos are then described, and the remaining chapters review experimental studies in a wide range of chemical and biochemical systems.
Asymmetric Synthesis
Authors: Procter Garry
Published: November 2023

This book covers a wide range of reactions which are of importance in the asymmetric synthesis of organic compounds. The principles of asymmetric additions to carbonyls, enolate alkylation, aldol reactions, additions to C-C double bonds, reduction and oxidation, rearrangements, and hydrolysis/ esterification reactions are covered, and selected examples used to illustrated the various topics. Numerous references to original literature should be of ues to organic chemists interested in the area of asymmetric synthesis.
Additions to C-C double bonds
Authors: Procter Garry
Published: November 2023

Additions to C-C double bonds represent an important general area for asymmetric synthesis, not Jeast because several chiral centres can be established in a single reaction. One of the most thoroughly studied class of reactions of this type is the Diels-Alder reaction and related 4+2 cycloadditions. In its most general form the Diets-Alder reaction involves three important components, the dienophile, the diene, and the catalyst. The last is not always necessary, but it is often difficult to achieve high levels of stereoselectivity without the help of a Lewis acid catalyst. In addition to increasing the rate of reaction, the catalyst usually improves the regioselectivity and stereoselectivity of the cycloaddition. A detailed discussion of the mechanism of Diels-Alder reactions, and related theory, is not within the scope of this volume. Nevertheless. a much simplified brief outline follows, in order to aid understanding of the models that have been proposed to account for the stereochemical outcome of the reactions which will be discussed.
Reduction and oxidation
Authors: Procter Garry
Published: November 2023

Asymmetric hydrogenation has been studied intensively for a relatively long time. In its usual form the reaction involves the addition of hydrogen to a double bond in the presence of a transition metal catalyst and a chiral, notacemic ligand. As with many enantioselective reactions which involve catalysis, a substrate, ligand, metal atom, and stoichiometric reagent are all involved in the transition state of the rate determining step. A typical catalytic cycle for asymmetric hydrogenation is shown schematically in Fig. 7.1.
Rearrangements
Authors: Procter Garry
Published: November 2023

The two main areas which will be considered in this chapter are sigmatropic reammgements and alkene isomerizations. There are numerous examples of the application of these two classes of reaction to the asymmetric synthesis of organic compounds, and in both cases a limited selection of examples will be presented in order to illustrate the principles and applications of these methods. Of most importance in asymmetric synthesis are 2,3. and 3,3-sigmatropic rearrangements typified by the Wittig and Claisen rearrangements respectively (Fig. 8.1). Taking these two as typical examples of their classes, some of the important general features of these reactions will be considered before specific examples of their use in asymmetric synthesis are discussed.
Conjugate addition–enolate-trapping
reactions
Authors: Suzuki M , Noyori R
Published: November 2023

Enolate anions are one of the most widely used nucleophilic species in organic synthesis. Organocopper conjugate addition to α,β-unsaturated carbonyl compounds generates in situ metal enolates under mild conditions with the incorporation of an organic group to the β-position. Therefore, the organocopper-mediated reaction followed by the regioselective enolate trapping provides an extremely powerful tool for controlled construction of organic frameworks (see Scheme 9.1). The organocopper reagents commonly used for this tandem reaction can be divided into four general classes: (1) Grignard reagents plus catalytic amounts of copper salts (RMgX + cat. CuX; X = Cl, Br, or I); (2) complexed mono-organocopper compounds (RCu complexed with phosphine, phosphite, or sulfide ligand); (3) homocuprates or mixed cuprates [MCuR2, MCuRR1, or MCuR(Z); M = Li or MgX, Z = C≡CPr or CN]; and (4) higher order cuprates [Li2CuR2(CN) or Li2CuRR1(CN)]. Homocuprates and higher order cuprates also include silylcuprates [Li2Cu(SiR3)2(CN)], stannylcuprates [Li2CuSnMe3(2-thienyl)(CN)], and aminocuprates ﹛LiCu[NSiMe3(CH2Ph)]2 and Li2Cu[NSiMe3(CH2Ph)2(CN)﹜. Although the combination of Grignard reagents and copper catalysts is often the first choice, lithium diorganocuprates and higher order cuprates have been used more widely in view of the higher efficiency, selectivity, and reproducibility of the conjugate addition reactions and the enhanced reactivity of the resulting enolate intermediates.
The Sonogashira Cu-Pd-catalysed alkyne coupling reaction
Authors: Campbell I B
Published: November 2023

Carbon–carbon bond-forming reactions are of crucial importance to the practising organic chemist. In particular, those which are technically simple, efficient, high-yielding, and which tolerate a wide variety of functional groups are of special use. One such reaction is the Sonogashira copper–palladium-catalysed coupling of terminal alkynes with aromatic and vinyl halides. The general forms of the reaction are given in eqns (1) and (2).
Kinetic and thermodynamic measurements
Authors: Magde Douglas , Van Eldik Rudi
Published: November 2023

This chapter describes the use of high pressures in the elucidation of the reaction mechanisms that govern chemical and biochemical processes near ambient conditions. In general, it is preferable that such investigations do not change the internal properties of molecules, but only perturb the molecules and their interactions by the minimum amount needed to measure the effect on their kinetic and thermodynamic behaviour. Since liquids are not very compressible, and solids are even less so, this modest aim still requires pressures up to 200 or 300 MPa. Over the past two decades, methods have been developed which allow virtually any kinetic or thermodynamic measurement to be performed at such pressures. The goal has been to devise instruments and procedures in which the rates or concentrations are measured in exactly the same manner as they are at ambient conditions. Protocols for such standard procedures are not included here. In order to permit coverage of the wide range of methods now available, we emphasize those aspects unique to operation at high pressures, including the selection or construction of a suitable apparatus, the choice of reaction conditions, the display of the pressure dependence of the data, and the interpretation of such data.
‘In situ’ crystallization techniques
Authors: Boese Roland , Nussbaumer Michael
Published: November 2023

The theory of the chemical bond has been much influenced by the structures that have been determined of certain key molecules. Single crystal X-ray diffraction is the most powerful and most widespread tool for determination of molecular structures, but it has a major disadvantage: the requirement of single crystals from samples which may be liquid or even gaseous at ambient conditions. Consequently, attempts were made quite early to grow crystals at low temperatures.
Molecular motion in crystals
Authors: Bürgi H B
Published: November 2023

The notion that molecules in crystals are static and undeformable objects, has been abandoned by crystallographers for some time now. Molecular flexibility in the solid state can be probed in several ways. One of them is to analyse in detail the structure of a molecule or molecular fragment in a variety of environment. This approach makes use of static structural data – distances, bond angles and conformational descriptors in particular; the structural parameters which are most susceptible to deformation, and also the type and extent of deformation, may be identified with the help of statistical methods. This way of drawing a parallel between the static and dynamic aspects of structure has become known under the heading of “Structure Correlation”. Many applications of the structure correlation method are reviewed in Bürgi and Dunitz (1993); others are described by Kaftory and by Klebe and Mietzner in this volume.
Correlation of crystal data to analyse and predict ligand-receptor interactions
Authors: Klebe Gerhard , Mietzner Thomas
Published: November 2023

A prerequisite for the rational design of biologically active compounds is the description and understanding of the structural and energetic interactions between a ligand of low-molecular weight (small molecule, e.g., a drug) and its macromolecular receptor (e.g., an enzyme).
Utilization of crystallographic results for selecting and designing pharmacologically active compounds
Authors: Karolak-Wojciechowska Janina
Published: November 2023

In the model presented for the utilization of crystallographic results, the atomic coordinates in the crystal structure are used as a starting point for searching for the conformation of a molecule that would correspond to the energy minimum (or several minima). It is assumed that this would be a conformation close to that existing in solution. To attain this aim it is necessary to carry out. Crystallographic analysis of the chosen compounds. Conformational analysis of the molecules by means of the molecular mechanics method. Molecular-orbital optimization of the geometry of all molecules, starting with the conformation obtained in 2.
Isomorphism, solid state transformations, and disorder in the crystal structures of cytidinium and 2’-deoxycytidinium salts
Authors: Jaskólski M , Wiewiórowski M
Published: November 2023

The organic building blocks of nucleic acids -nucleosides -have been, and still are, rewarding objects of studies in the domain of organic crystal chemistry. Those studies have been the source of geometrical data which, in the past, were essential for compiling standard-group dictionaries used in structural studies of oligomers and polymers (Sussman, 1985; Westhof, Dumas & Moras, 1985) and, more recently, entered (in the form of parameters) the molecular dynamics protocols of refinement of macromolecular structures (Briinger, Kuriyan & Karplus, 1987). The past success of crystallography of low-molecular-weight components of nucleic acids does not mean that its role has been fulfilled. Accumulation of experimental data is still important for conformational studies of the flexibility (or rigidity?) of the nucleotide and nucleoside.
Total Synthesis of Neodolabellenol
Authors: Williams D R , Coleman, P J
Published: November 2023

Discussion Points Propose a synthesis of 1 starting from 2-methyl-2-cyclopentenone. The direct use of the vinyl lithium species generated from 2 preferentially afforded the Z-allylic alcohol in the coupling process c. Explain the change in stereoselectivity. Give an explanation for the preferential formation of the β-epimer in the Julia coupling j. A small amount of compound 7 was isolated from the Julia coupling. Give an explanation for its formation. Further Reading For another application of the Julia coupling to the synthesis of macrocycles, see: K. Takeda, A. Nakajima and E. Yoshii, Synlett, 1995, 3, 249. For various aspects of organocuprate-mediated epoxide opening, see: H. Bruce, R. S. Wilhelm, J. A. Kozlowski and D. Parker, J. Org. Chem., 1984, 49, 3928.
Total Synthesis of Octalactins A and B
Authors: McWilliams J C , Clardy J
Published: November 2023

Discussion Points Propose a mechanism for the cyclisation step f. Why is the seven­ membered cyclisation product 5 favoured over a six-membered ring system? What is the purpose of the tin tetrachloride in step i? Explain the regioselectivity obtained in steps j and s. Rationalise the stereoselectivity of these oxidative ring expansion steps. Give a motive for the acidic conditions adopted in step t. Further Reading For an extensive review on the Baeyer-Villiger reaction see: G. R. Krow, Org. React.,1993, 43,251.
Total Synthesis of (—)-Solavetivone
Authors: Hwu J R , Wetzel, J M
Published: November 2023

Discussion Points Suggest a mechanism for step d. The conversion of compound 6 into the tri none 7 was carried out in a single oxidative step. Propose alternative methods for the introduction of α, β unsaturation in a ketone. What factors govern the regioselectivity and stereoselectivity of the conjugate additon of the trimethylsilyl nucleophile in step g? A homonuclear NMR decoupling experiment was carried out on compound 11, simultaneously irradiating the two proton signals at δ 4.69 and 4.70 ppm. This resulted in the simplification of the single proton multiplet between δ 2.35–2.87 ppm. In a subsequent nOe experiment an 18% enhancement of the aforementioned multiplet was observed on irradiation of a methyl group doublet at 6 1.26 ppm. Rationalise the above observations in terms of the structure and stereochemistry given for 11. Suggest a mechanism for the Lewis acid catalysed rearrangement in step I.
Synthesis of a Key Intermediate of 1β-Methylcarbapenem Antibiotics
Authors: Kang S -H , Lee, H -S
Published: November 2023

Discussion Points When epi-3was submitted to the sequence outlined in steps d and e, a mixture of diastereoisomers was formed. Propose their structure and explain the reduced stereoselectivity observed. How could epi-3be converted into compound 3? What is the purpose of hydroquinone in step e? Give the structure of the reactive intermediate of step k. Further Reading For a review of the use of protected cyanohydrins as acyl anion equivalents, see: J. D. Albright, Tetrahedron,1983, 39,3207. For reviews on nitrone cycloadditions to olefins, see: P. N. Confalone and E. M. Huie, Org. React.,1988, 36,1; R. Annunziata, M. Cinquini, F.Cozzi and L. Raimondi, Gazz. Chim. Ital.,1989, 119,253. For reviews of the Mitsunobu reaction, see: D. L. Hughes, Org. React.,1992, 42,335;D. L. Hughes, Organic Preparations and Procedures Int.,1996, 28,127.