bluuebunny/crossref_metadata_2025_split huggingface dataset:
35.1.1.6.2 Synthesis by Substitution of Sulfur, Selenium, or Tellurium Functionalities (Update 2014)
Authors: Margaretha P. 
Published: May 2016

AbstractThis is an update to Science of Synthesis Section 35.1.1.6, describing the synthesis of chloroalkenes from sulfur-, selenium-, or tellurium-substituted alkyl compounds and covers the literature up until late 2013.
35.1.4.2.4 Synthesis by Substitution of σ-Bonded Heteroatoms (Update 2014)
Authors: Margaretha P. 
Published: May 2016

AbstractThis update summarizes reactions wherein allylic alcohols (or their anions) are transformed into rearranged allylic chlorides via an SN2′-reaction. It covers the literature up until late 2013.
39.19.1.2 Alkaneselenolates of Group 1, 2, and 13–15 Metals (Update 2013)
Authors: Santi C. 
Published: May 2016

AbstractThis chapter is an update to the earlier Science of Synthesis contribution describing the preparation of acyclic alkaneselenolates of metals in groups 1, 2, and 13–15. It focuses on the literature published in the period 2001–2012, and some aspects of the reactivity of these compounds are also described.Alkaneselenolates are usually prepared in situ under inert conditions and are immediately used for subsequent reactions, most typically nucleophilic substitutions.
39.19.2.3 Alkaneselenolates of Group 3–12 Metals (Update 2014)
Authors: Polo A. , Real J. 
Published: May 2016

AbstractThis chapter is an update to the earlier Science of Synthesis contribution (Section 39.19.2) describing methods for the synthesis of transition metal selenolates and their applications in organic synthesis. Synthetic methods developed in recent years concern both terminal and bridging alkaneselenolates. New applications for this class of compounds in organic synthesis have not been proposed. However, compounds of this class have been postulated as catalytic intermediates in some reactions, such as transition-metal-catalyzed Se-C bond formation via cross-coupling reactions.
39.26.6.2 Cyclic Alkaneselenolates of Group 3–12 Metals (Update 2014)
Authors: Polo A. , Real J. 
Published: May 2016

AbstractThis chapter is an update to the earlier Science of Synthesis contribution (Section 39.26.6) describing methods for the synthesis of cyclic alkaneselenolates of transition metals and their applications in organic synthesis. Synthetic methods developed in recent years concern diselenolates, aminoselenolates, and selenolates with a metal-carbon bond. New applications for this class of compounds in organic synthesis have not been proposed.
39.32.2.2 Alkanetellurolates of Group 3–12 Metals (Update 2014)
Authors: Polo A. , Real J. 
Published: May 2016

AbstractThis chapter is an update to the earlier Science of Synthesis contribution (Section 39.32.2) describing methods for the synthesis of transition metal alkanetellurolates and their applications in organic synthesis. Synthetic methods developed in recent years concern both terminal and bridging alkanetellurolates. New applications for this class of compounds in organic synthesis have not been proposed. However, they have been postulated as catalytic intermediates in some transition-metal-mediated cross-coupling reactions.
39.39.6.2 Cyclic Alkanetellurolates of Group 3–12 Metals (Update 2014)
Authors: Polo A. , Real J. 
Published: May 2016

AbstractThis chapter is an update to the earlier Science of Synthesis contribution (Section 39.39.6) describing methods for the synthesis of cyclic alkanetellurolates of transition metals and their applications in organic synthesis. Synthetic methods developed in recent years focus principally on the synthesis of ditellurolates and aminotellurolates. New applications for this class of compounds in organic synthesis have not been proposed.
3.1.1.1.2 Reaction with (Het)Arylmetals or (Het)Arenes
Authors: Werner E. , Sigman M. S. 
Published: May 2016

AbstractThe intermolecular Heck reaction, in which a vinylic C—H bond is replaced by a C—C bond under palladium catalysis, is an indispensible tool for synthetic organic chemists. The reasons for this reliance include predictable regioselectivity in the formation of the new C—C bond when electronically biased alkenes are used, and the dependable delivery of configurationally pure E-alkene products. When palladium(II) salts are employed as catalysts in conjunction with organometallic reagents, an external oxidant is required to render the reaction catalytic. This strategy enables the reaction to perform well under mild conditions as compared to the elevated temperatures typically required when using palladium(0) catalysts. A critical review of the reagents and conditions capable of performing such transformations upon electron-deficient alkene substrates is presented.
3.1.1.1.3 Reaction with Arene- or Hetarenecarboxylic Acids or Derivatives, or Related Compounds
Authors: Zhang M. , Su W. 
Published: May 2016

AbstractThis chapter presents the synthesis of aryl-substituted alkenes via transition-metal-catalyzed decarbonylative, decarboxylative, or desulfinylative Mizoroki–Heck cross-coupling reactions.
3.1.1.1.4 Reaction with Nonaromatic Halides, Sulfonates, or Related Compounds
Authors: Weimar M. , Fuchter M. J. 
Published: May 2016

AbstractThe Heck reaction is a widely used method in organic synthesis. This report concerns the development of methodologies to apply Heck-type chemistry to electron-poor alkenes with one or more electron-withdrawing groups and alkenyl and other nonaromatic electrophiles.
3.1.1.3.2 Reaction with Arylboronic Acids or Derivatives or Aroyl Halides
Authors: Lindh J. , Larhed M. 
Published: May 2016

AbstractThe use of electron-rich alkenes in Heck reactions was originally associated with poor regiocontrol, resulting in unwanted mixtures of regioisomers, thus severely hampering the utility of electron-rich alkenes. Today, excellent regiocontrol can be obtained by employing suitable reaction conditions. The use of electron-rich alkenes, such as enamides and vinyl ethers, in coupling reactions with arylboron compounds under cationic conditions provides easy access to the corresponding aryl ketones. Additionally, vinyl acetate can function as a convenient ethene precursor to form styrenes in coupling reactions with arylboron compounds.
3.1.1.3.3 Reaction with Nonaromatic Alkenyl Halides or Alkenyl Sulfonates
Authors: Nilsson P. 
Published: May 2016

AbstractThe intermolecular coupling of two sp2-hybridized carbons is normally conveniently performed via, for example, a Suzuki or Stille reaction. However, easy access to suitably equipped starting materials, i.e. a boron or tin derivative and an aryl/vinyl halide, is not always straightforward, especially if there is an intention to couple two alkenes, thus forming conjugated dienes. In such cases the corresponding palladium(0)-catalyzed Mizoroki–Heck vinylation procedure becomes interesting since the vinyl halide (or pseudohalide) is coupled to the other alkene via a 1,2-insertion/β-hydride elimination process and thereby offers a complementary set of coupling partners as starting materials, as well as giving good stereoselectivity. In addition, heteroatom-substituted alkenes present an opportunity for subsequent transformations on the functionalized 1,3-diene, in contrast to cross couplings where the heteroatom constitutes a part of the leaving group. This chapter summarizes developments in the field of Mizoroki–Heck vinylation of electron-rich alkenes using alkenyl—X species (X = halide, sulfonate), focusing on reactions where high yields and regioselectivities are achieved using robust protocols.
3.1.1.5 Alkenes with Metal-Directing Groups as Reaction Components
Authors: Trejos A. , Odell L. R. 
Published: May 2016

AbstractThe use of electron-rich alkenes in Heck reactions was originally associated with poor regiocontrol, resulting in unwanted mixtures of regioisomers, thus severely hampering the utility of electron-rich alkenes. Chelation control has arisen as an attractive strategy to dictate the product outcome, as the directing effect of these substrates and the favorable formation of five- or six-membered chelates result in excellent regioselectivities. Today, excellent regiocontrol can be obtained by employing alkenes containing suitable catalyst-presenting groups. In addition, high levels of stereocontrol can also be obtained by using appropriate chiral catalyst presenting groups.
3.1.2.1 Formation of Carbocycles
Authors: Geoghegan K. , Evans P. 
Published: May 2016

AbstractThe intramolecular Mizoroki–Heck reaction is an important method for the formation of cyclic molecules, which would often be nontrivial to assemble by alternative means. Coupling between an sp2-hybridized carbon atom and an alkene generates a C—C bond which is included within a newly formed ring. In the absence of an additional coupled process, a new alkene is also generated. A variety of ring sizes may be accessed in this class of reaction and in many instances the adducts may be isolated in excellent chemical yield. The process is typically effected under the influence of palladium catalysis and the many published examples indicate that a variety of functionalities may be tolerated without interference. Within this chapter, examples have been selected from the recent literature to illustrate the utility of this method for the construction of carbocyclic compounds.
2.1.2 In Situ Generation of the α,β-Unsaturated Carbonyl Component by Wittig-Type Reaction
Authors: Alavijeh N. S. , Ghabraie E. , Balalaie S. 
Published: May 2016

AbstractThis chapter describes various multicomponent reactions (MCRs) involving in situ generated α, β-unsaturated carbonyl compounds formed by Wittig-type reactions.
2.1.3 With Isocyanide Participation
Authors: Shaabani A. , Sarvary A. , Shaabani S. 
Published: May 2016

AbstractIsocyanide-based multicomponent reactions represent a very important synthetic method for the synthesis of heterocyclic compounds with potential biological and medicinal activities. The nucleophilic property of isocyanides makes them a popular reactant class for the development of novel multicomponent reactions. One of the isocyanide-based multicomponent reaction approaches involves the generation of a dipolar intermediate by the addition of isocyanides to electron-deficient α, β-unsaturated carbonyl compounds such as dialkyl acetylenedicarboxylates; the dipolar intermediate can then be captured efficiently by various dipolarophiles such as CH-, NH-, and OH-acids, electron-deficient alkenes, and imines to form diverse cycloadducts.
2.6.2 Catalytic Metal Participation
Authors: Arndtsen B. A. , Tjutrins J. 
Published: May 2016

AbstractTransition-metal-catalyzed multicomponent reactions are of great utility in organic synthesis. These transformations exploit the reactivity of metal catalysts to both activate simple substrates toward reactions, and control how they react, thereby allowing the assembly of structurally complex products in an efficient fashion via the coupling of simple building blocks. This chapter highlights a number of important examples of such transformations, with a focus on those that lead to formation of three or more bonds, from substrates that are both widely available and easily tuned.
1.1.2 Asymmetric Hydroformylation of Alkenes
Authors: Godard C. , Perandones B. F. , Claver C. 
Published: May 2016

AbstractAsymmetric hydroformylation is a very promising catalytic reaction that produces chiral aldehydes from inexpensive feedstocks (alkenes and syngas) in a single step under essentially neutral reaction conditions. Asymmetric hydroformylation offers a great potential for the fine chemical industry since enantiomerically pure or enriched aldehydes can be obtained through hydroformylation of a variety of substrates using the appropriate chiral-phosphorus-modified rhodium catalyst. This chapter presents the successful transformations of benchmark and specific substrates, organized according to the substitution pattern.
1.1.4 Nonconventional Reaction Media: Hydroformylation, Carbonylation, and Hydroxycarbonylation of Alkenes
Authors: Mortreux A. , Sauthier M. , Monflier E. , Tilloy S. 
Published: May 2016

AbstractThis chapter focuses on catalytic reactions involving the use of carbon monoxide and alkenes together with tertiary substrates such as hydrogen, alcohols, amines, or water where the catalyst recovery and recycling has been emphasized via the use of biphasic media. These atom-economical catalytic reactions result in the synthesis of aldehydes, esters, amines, and carboxylic acids, as well as polyketones, where the activity and regioselectivity concerns have been addressed.
1.1.9 Hydrocyanation of Alkenes
Authors: Tauchert M. E. 
Published: May 2016

AbstractHydrocyanation of alkenes is an atom-economical reaction to install a functionalized C-1 building block into a molecule. The reaction can be run to yield either the linear or the branched nitrile product. Branched nitriles can be produced in moderate to good enantiomeric excess. A detailed overview of the mechanism of nickel-catalyzed hydrocyanation is provided to help assess the scope and limitations of this reaction.
1.1.10 Stereoselective Conjugate Addition of Methyl and Cyanide
Authors: Goldfuss B. 
Published: May 2016

AbstractConjugate additions of methyl and cyanide nucleophiles to Michael acceptors are powerful methods for stereoselective homologation. New ligands and a variety of copper sources today enable highly enantioselective nucleophilic 1,4-methylations. Besides Grignard reagents, methylzinc reagents and trimethylaluminum are well established as nucleophilic methyl sources. Enantioselective cyanations of alkenes, aldehydes, or imines can be accomplished with metal catalysts (e.g., based on nickel, aluminum, or titanium) or organocatalysts, mostly employing silyl cyanides or acetone cyanohydrin as the cyanide source.
1.1.11 Enantioselective Conjugate Addition of Nitromethane
Authors: Ballini R. , Petrini M. 
Published: May 2016

AbstractThe enantioselective conjugate addition of nitromethane to electron-poor alkenes is a powerful synthetic strategy allowing the introduction of a single carbon linked to a nitrogen atom in its higher oxidation state. The installation of a newly generated stereocenter in enantioenriched form and the subsequent reduction of the nitro group to an amino functionality represents a flexible gateway to the preparation of optically active amino-containing compounds. Organocatalytic methods are the most exploited procedures for this purpose and may involve activation of the carbonyl group in the corresponding enones and enals by optically active secondary amines (iminium ion catalysis). Activation of nitromethane using thiourea derivatives is also a viable approach to attain the corresponding adducts with high enantioselectivity. Chiral complexes of lanthanum, aluminum, and copper are also successfully used for this purpose and are substantially based on the activation of both nitromethane and the Michael acceptor.
1.3.2 Cyanation of Ketones, Aldehydes, and Imines
Authors: Lin L. L. , Liu X. H. , Feng X. M. 
Published: May 2016

AbstractThe synthesis of various cyanohydrins and α-aminonitriles is achieved through the cyanation of aldehydes, ketones, aldimines, and ketimines using different cyanide sources and is catalyzed by chiral or achiral organic or metallic catalysts.
2.1.1 Cyanohydrin Formation/Henry Reaction
Authors: Steiner K. , Glieder A. , Gruber-Khadjawi M. 
Published: May 2016

AbstractEnantiopure cyanohydrins and β-nitro alcohols serve as versatile building blocks for a broad range of chemical and enzymatic reactions, resulting in highly valuable products for many applications. Hydroxynitrile lyases comprise a diverse group of enzymes that catalyze the reversible cleavage of cyanohydrins to carbonyl compounds and hydrogen cyanide. The enzymes have been studied broadly concerning their substrate scope, specificity, structure, and reaction mechanism, and many have been successfully applied and engineered for the synthesis of cyanohydrins from laboratory to industrial scale. Both R- and S-cyanohydrins are accessible from a broad variety of substrates and, in most cases, high yields and enantiopurities can be obtained after enzyme and reaction engineering. Recent progress in the development and optimization of heterologous expression systems make recombinant hydroxynitrile lyases available in the quantities needed for industrial production. The procedures for safe handling of cyanides are also well-defined and established. In addition, some hydroxynitrile lyases are able to catalyze the nonnatural asymmetric Henry reaction. Although the enzyme activities are rather low, the enzymatic synthesis of enantiopure β-nitro alcohols shows promising results.
2.1.5 Addition to C=N Bonds
Authors: Ilari A. , Bonamore A. , Boffi A. 
Published: May 2016

AbstractThe Pictet–Spengler reaction consists of a Mannich-type cyclization in which an electron-rich aromatic carbon attacks a C=N bond, in the form of an electrophilic iminium ion, thus yielding a heterocyclic scaffold and generating a new asymmetric center. In this chapter, the substrate scope and limitations of the best-known Pictet–Spenglerase enzymes are discussed in order to pave the way for development of a general biocatalytic strategy for the stereoselective addition to the C=N bond.
2.3.2 Addition of Water to C=C Bonds
Authors: Resch V. , Hanefeld U. 
Published: May 2016

AbstractWhile chemists struggle to find efficient methods to perform the asymmetric addition of water, nature employs countless enzymes (called hydratases or hydro-lyases) to perform this reaction using substrates with both activated and nonactivated double bonds. However, compared to the vast number of hydratases involved in metabolic pathways in nature, only a few are described for their use in organic synthesis. Nevertheless, their potential in asymmetric catalysis has been recognized and some hydratases are used on a large scale in industrial processes. Since hydratases perform the addition of water, water is used as both a solvent and a reagent, opening up a very efficient and green route to both secondary and tertiary alcohols. This chapter focuses on hydratases that catalyze interesting reactions and are tested beyond their biochemical characterization.
2.4.2 Imine Reductases
Authors: Leipold F. , Hussain S. , France S. P. , Turner N. J. 
Published: May 2016

AbstractImine reductases catalyze the asymmetric reduction of imines to the corresponding chiral amines. The excellent enantioselectivities achieved in these conversions make this biocatalyst an attractive addition to the toolbox for chiral amine synthesis. This chapter details recent developments in the application of different classes of imine reductases in the synthesis of chiral amines as well as amino acids.
1.1.4 Arylation Using a Ruthenium(II) Catalyst
Authors: Seki M. 
Published: May 2016

AbstractThe C—H arylation of α-functionalized benzenes proceeds smoothly in the presence of a ruthenium(II) catalyst. Key factors which control the reaction (catalyst, leaving group, additive, phosphine ligand, and base) are thoroughly discussed in terms of the efficiency and practicality of the process. Of particular interest is the synthesis of biaryls by means of C—H arylation, as these constitute a key feature of some important pharmaceutical compounds.
1.1.5 Vinylation Using a Palladium Catalyst
Authors: Dornan P. K. , Dong V. M. 
Published: May 2016

AbstractThis chapter covers methods for the vinylation of non-heteroaromatic arene C—H bonds with palladium catalysts. Both oxidative methods (dehydrogenative coupling of an arene with an alkene) and direct arylation methods (coupling of an arene with a vinyl halide or equivalent) are discussed. In many cases, directing groups are used to enhance reactivity and ensure site-selective vinylation. Examples of non-directed cases are also discussed. These vinylation methods are advantageous over other cross-coupling methods since pre-activation of the arene component (via an aryl halide or arylmetal species) is not necessary.
1.1.7 Metal-Catalyzed C—H Alkylation Using RX Compounds
Authors: Yi C. S. 
Published: May 2016

AbstractThis review covers transition-metal-catalyzed C(sp2)—H alkylation methods via carbon—heteroatom bond cleavage. The first part of the review delineates catalytic C(sp2)—H alkylation methods for arene and alkene substrates using various alkyl halides. Subsequently, alkylation by cleavage of C—B, C—Si, and C—Sn bonds is described. Finally, C(sp2)—H alkylation via C—O and C—S bond cleavage is reviewed.
Medial septal GABAergic projection neurons promote object exploration behavior and type 2 theta rhythm
Authors: Gangadharan Gireesh , Shin Jonghan , Kim Seong-Wook , Kim Angela , Paydar Afshin , Kim Duk-Soo , Miyazaki Taisuke , Watanabe Masahiko , Yanagawa Yuchio , Kim Jinhyun , Kim Yeon-Soo , Kim Daesoo , Shin Hee-Sup 
Published: May 2016

SignificanceTwo different kinds of exploratory behavior, object and place, have been proposed. Their distinction has been debated, however, because of the lack of solid experimental evidence to support their heterogeneity. In this report, we show neural evidence for the heterogeneity of exploratory behaviors. Thus, we demonstrate that T-type Ca2+channels in the septo-hippocampal GABAergic pathway play a specific role in control of exploratory behavior of novel objects. In addition, we show that type 2 but not type 1 hippocampal theta rhythm is associated with object exploration.
‘You Will Take This Sacred Book’: The Musical Strambotto as a Learned Gift
Authors: Zanovello Giovanni 
Published: May 2016

AbstractThe MS Modena, Biblioteca Estense e Universitaria, α.F.9.9 is by far the most lavish collection produced in the short-lived history of the musical frottola. In its pages, unassuming four-voice secular settings are preceded by citations from Pliny and Isidore and surrounded by dazzling illuminations of birds, fruits and plants. If splendour is never amiss in gifts, one must wonder what the relationship was between the components of this intriguing artefact. In this article I investigate the gift value of the source by examining the musical repertory and style in conjunction with its other features. I propose that musical strambotti enabled fifteenth-century educated Italians to perform symbolic gestures associated with ancient music. The repertory was also perfectly congruous with the poetic and decorative choices made for the manuscript. The examination of this peculiar source helps shed more light on the musical strambotto, its uses and its implied cultural associations.
Trade Policy Coordination and Food Price Volatility
Authors: Gouel Christophe 
Published: May 2016

AbstractMany countries adjust their trade policies counter‐cyclically with food prices, to the extent that the use of restrictions by food‐exporting countries has occasionally threatened the food security of food‐importing countries. These trade policies are inconsistent with the terms‐of‐trade motivation often retained to characterize the payoff frontier of self‐enforcing trade agreements, as they can worsen the terms of trade of the countries that apply them. This article analyzes trade policy coordination when trade policies are driven by terms‐of‐trade effects and a desire to reduce domestic food price volatility. This framework implies that importing and exporting countries have incentives to deviate from cooperation at different periods: the latter when prices are high and the former when prices are low. Since staple food prices tend to have asymmetric distributions, with more prices below than above the mean but with occasional spikes, a self‐enforcing agreement generates asymmetric outcomes. Without cooperation, an importing country uses its trade policy more frequently because of the concentration of prices below the mean, but an exporting country has a greater incentive to deviate from a cooperative trade policy because positive deviations from the mean price are larger than negative ones. Thus, the asymmetry of the distribution of commodity prices can make it more difficult to discipline export taxes than tariffs in trade agreements.