bluuebunny/crossref_metadata_2025_split huggingface dataset:
A quantumchemical study of the C6H+5 potential energy surface. Evidence for a nonclassical pyramidal carbenic species
Authors: Castenmiller W.A.M. , Buck H.M. 
Published: September 2010

AbstractMINDO/3 and STO‐3G MO calculations including geometry optimization have been performed for nonlinear C6H+5 structures. The phenyl cation 5 is the lowest energy compound on the surface, followed by the nonclassical pyramidal carbenic structure 4. Other local minima include the bicyclic carbene 6 and the benzvalenyl cation 7. Fairly good agreement between the results from both methods was obtained. The electronic structure of 4 is explained using orbital interaction diagrams which show the stabilization of the cyclopentadienyl cation by the apical carbon atom and the relation between 4 and pyramidal transition‐metal complexes. The electronic structure of 6 is related to that of the bicyclo[3.1.0]hexenyl cation 12. Activation energies for rearrangement reactions on the energy surface show that 4 can probably be studied starting from benzvalene‐type precursors.
Boron trifluoride catalysed rearrangement and decarbonylation of quinoid γ‐oxo‐α,β‐unsaturated thiolesters. α‐Alkylthio‐γ‐lactones
Authors: Mosterd A. , Bos H.J.T. 
Published: September 2010

AbstractUnder the influence of boron trifluoride quinoid γ‐oxo‐α,β‐unsaturated thiolesters (5) and (10) rearrange into α‐alkylthio‐γ‐lactones (6) and (9), respectively, in yields of 50–90%. In the case of S‐alkyl 2‐(10‐oxo‐9‐phenanthrenylidene)alkanethioates (13) decarbonylation occurs with formation of α,β‐unsaturated ketones (14). Mechanisms are proposed. The γ‐oxo‐α,β‐unsaturated thiolesters were prepared in situ from a 1‐alkynyl sulfide and 3,5‐di‐tert‐butyl‐o‐benzoquinone or 9,10‐phenanthroquinone, under the influence of boron trifluoride.
Thiophene analogues of estrone; synthesis and structural assignment
Authors: Corvers A. , Scheers P.C.H. , de Haan J.W. , Buck H.M. 
Published: September 2010

AbstractThe synthesis of tetracycles of type 1 is described. Both la and lb are converted into the estrogen‐like compounds 12a and 12b via the corresponding α‐epoxides. The β‐epoxides yield mixtures of dienes. The stereochemical influence of the base on the alkene precursors for tetracyclic compounds, formed under Wittig‐Schlosser conditions, has been established. Finally, evidence is offered for the trans,anti,trans geometry in the tetracyclic molecules under discussion.
Preparation, structure and properties of complexes with the bis(di‐n‐butyldithiocarbamato)arsenic(III) or antimony(III) cation
Authors: van de Leemput P. J. H. A. M. , Cras J.A. , Willemse J. 
Published: September 2010

AbstractThe preparation, structure and some physical properties of cationic dithiocarbamatoarsenic(III) and ‐antimony(III) compounds [M(Bu2dtc)2] + X− [X = I−3 for M = As and Sb; X = Cd2I2−6 for M ‐ Sb and Bu2dtc− = Bu2NC(S)S−] are reported. [Sb(Bu2dtc)2]2Cd2I6, crystallizing in the monoclinic space group P21/n with a = 16.236(6), b = 12.573(5), c = 16.126(5) Å, β = 94.13(2)°, V = 3283 Å3 and Z = 2, contains Sb in pseudo‐trigonal‐bipyramidal coordination, with a stereoactive lone pair in an equatorial position. The Bu2dtc groups are asymmetrically bonded, with their largest Sb‐S bonds in equatorial direction.
Synthesis of substance P via its sulfoxide by the repetitive excess mixed anhydride (REMA) method
Authors: Izeboud E. , Beyerman H. C. 
Published: September 2010

AbstractThe N‐protected heptapeptide sulfoxide corresponding to positions 5 to 11 inclusive of substance P, Boc‐Gln‐Gln‐Phe‐Phe‐Gly‐Leu‐Met(O)‐NH2 (VII), was synthesized by the repetitive excess mixed anhydride (REMA) method (Scheme). Consecutive mixed anhydride coupling to N‐deprotected VII of the dipeptides Boc‐Lys(Z)‐Pro‐OH (VIII) and Z‐Arg(NO2)‐Pro‐OH (X) yielded protected substance P sulfoxide, XI. From XI both Z groups and the NO2 group were removed with liquid hydrogen fluoride, yielding substance P sulfoxide.Substance P sulfoxide was conveniently reduced to substance P with the aid of iodide ions in strongly acid olution. Preliminary results are given on the scope of this method, i.e. peptides containing ‐ besides methionine ‐ tyrosine, where the method worked well, or tryptophan, where the method failed.REMA‐synthesized substance P, after gel filtration, was found to be chemically pure and to possess the same biological activity as a substance P standard (Beckman), according to two tests (sialagogic assay and guinea pig ileum contraction).
Synthese von Bicyclo[3.2.n]alka‐2,6‐dienen und Bicyclo[3.2 + n.0]alka‐2,n + 4‐dienen aus 1,3‐cycloalkadienen
Authors: Japenga J. , Klumpp G. W. , Kool M. 
Published: September 2010

AbstractThermolysis (350°C, 2 sec) of mixtures of the endo‐ and exo‐epimers of (n + 5)‐vinyl‐bicyclo[n + 2.1.0]alk‐2‐enes [n = 2, 3, 4; prepared by a sequence of reactions starting with the addition of (methoxycarbonyl)carbene to an appropriate 1,3‐cycloalkadiene] yields bicyclo[3.2.n]‐alka‐2,6‐dienes. Bicyclo[5.3.0]deca‐2,7‐diene is obtained by thermolysis (550°C, 2 sec) of bicyclo‐[3.3.2]deca‐2,9‐diene.
Oxydation des alcools. II ‐ Mesure des effets isotopiques secondaires du deutérium pour déterminer le mécanisme de l'étape lente de la réaction d'oxydation par le chrome (VI)
Authors: Durand R. , Geneste P. , Lamaty G. , Moreau C. , Pomarès O. , Roque J. P. 
Published: September 2010

AbstractThe nature of hydrogen transfer occurring during the slow step of the oxidation reaction of the alcohol using chromic acid has been studied by measuring the secondary deuterium isotope effects. The results obtained with cyclohexanol (kH/kD = 1.25); cis‐4‐tert‐butylcyclohexanol (kH/kD = 1.44); trans‐s‐4‐tert‐butylcyclohexanol (kH/kD = 1,10); exo‐2‐norbornanol: exo‐3‐d1 (kH/kD = 0.99), endo‐3‐d1 (kH/kD = 1.09), 3‐3‐d2 (kH/kD = 1.07); endo‐2‐norbornanol: exo‐3‐d1 (kH/kD = 1.05), endo‐3‐di (kH/kD = 1.00) and 3‐3‐d2 (kH/kD = 1.07) are more in agreement with a proton transfer than with a hydride transfer if there is no important structural modification of the chromic esters.
Ring transformations of heterocycles by oxidizing agents. A 14C study of the conversion of cinnolines into indazoles
Authors: van der Plas H. C. , Buurman D. J. , Vos C. M. 
Published: September 2010

Abstract5‐Nitro‐ and S‐nitro[4‐14C]cinnoline have been prepared. Oxidation of those compounds by hydrogen peroxide in acetic acid gave 4‐nitro[3‐14C]‐ and 7‐nitro[3‐14C]indazole, respectively. The indazoles have nearly the same specific radioactivity as the cinnolines, leading to the conclusion that only the C(3) atom of the cinnoline ring is expelled. A mechanism for the ring transformation is proposed.
2‐(Arylimino)imidazolidines; synthesis and hypotensive activity
Authors: Timmermans P. B. M. W. M. , van Zwieten P. A. , Speckamp W. N. 
Published: September 2010

AbstractThe synthesis of various 2‐(arylimino)imidazolidines is described. Most compounds were prepared by reaction of N‐aryl‐S‐methylisothiuronium iodides or N‐aryldichloroimines with ethylene‐diamine. The derivatives differ in substitution in the aromatic moiety. The hypotensive activity of the imidazolidines has been measured following intravenous administration to anaesthetized, normotensive rats. Big differences in hypotensive activity exist within the present series of structurally related compounds.
A new synthesis of allenic hydrocarbons from tertiary 2‐propynyl sulfinates and organocopper(I) compounds. Evidence for a syn‐l,3‐substitution pattern in the steroid series
Authors: Vermeer P. , Westmijze H. , Kleijn H. , van Dijck L. A. 
Published: September 2010

AbstractIn tetrahydrofuran tertiary 2‐propynyl sulfinates R1‐C≡C‐C(R2,R3)‐OS(O)Me (1) are smoothly converted in a 1,3‐substitution reaction into allenic hydrocarbons RR1CCCR2R3 (4) by organoheterocuprates of the type (RCuBr)MgX. Generally, much attack on the sulfur atom in 1 is observed when this compound is treated with (RCuBr)MgX in diethyl ether, or with R2CuMgX in diethyl ether or in tetrahydrofuran. The stereochemical course of the allene formation has been studied in the case of the sulfinic ester 5, derived from the steroid “Mestranol”. It is found that the syn‐1,3‐substitution product 6 is exclusively formed from 5 and the heterocuprates (MeCuBr)MgCl or (MeCuBr)MgCl·LiBr. Most likely, copper(III) species are formed in the first step of the 1,3‐substitution reactions described.
The electrocatalytic reduction of nitrogen compounds. Part II: The influence of the electrode material on the electrochemical reduction of nitrite
Authors: van der Plas J. F. , Barendrecht E. 
Published: September 2010

AbstractThe electrochemical reduction of nitrite was studied at several electrode materials in 7.5 M sulfuric acid solutions. The thin oxide films on the noble metals, Pt, Ir and Rh, did not interfere with the reduction process. A thick oxide layer, as on Nb and Ta, however, did shift positively the reducing potential by several hundreds of mV.In these solutions, the protecting layer on a lead electrode (lead sulfate) behaved in the same manner. From the decrease in the current in repeated cyclic experiments, it could be concluded that poisoning of the active surface sites of the electrodes by oxygen did change the reduction mechanism of nitrite.
On the conformation and dimerization of a 2‐mercapto‐5‐methylenepiperazine‐3,6‐dione
Authors: Noordik Jan H. , Herscheid Koos D. M. , Tijhuis Marianne W. , Ottenheijm Harry C. J. 
Published: September 2010

AbstractAn X‐ray crystal structure analysis of 9,9a‐dihydro‐l,9,9‐trimethyl‐2‐methylene‐3,10‐diketo‐9a‐mercapto‐piperazino[1,2‐a]indole (1) shows a boat conformation for the piperazinedione ring in this compound. This observation supports the previously suggested Zn++ chelate 3 as an intermediate in the conversion of 1 into 2. Crystals of 1 are monoclinic, a = 12.751 (7)å, b = 7.439 (2) Å, c = 15.324 (15) Å,β = 98.73(6)°; space group: P21/n,Z = 4. In solution at room temperature 1 dimerizes to 4 with loss of one molecule of H2S.
A NMR study on the ring contraction of N‐methylpyrimidinium salts into pyrazoles
Authors: Brouwer M. S. , van der Plas H. C. , van Veldhuizen A. 
Published: September 2010

Abstract1H‐NMR evidence is presented for the covalent hydrazination of 1‐methyl‐, 1,2‐dimethyl‐, 1,4,6‐trimethyl‐ and l‐methyl‐4‐phenyl‐pyrimidinium iodide (1a‐d) at C(6). With fully deuterated hydrazine hydrate the salts 1a‐d undergo ring contraction into pyrazole and pyrazole derivatives (8a‐d) containing deuterium at position 4. Evidence is presented for the intermediacy of a tautomeric mixture of open‐chain compounds, in which H/D exchange occurs before cyclisation takes place.
Long‐range carbon‐proton spin‐spin coupling constants. A 13C NMR study of monohalogen substituted ethanes and propanes
Authors: Spoormaker Tom , de Bie Marius J. A. 
Published: September 2010

AbstractThe analysis of single resonance 13C FT NMR spectra has provided all long range 13C‐1H coupling constants in the monohalogeno‐ethanes and ‐propanes. In addition, all directly bonded 13C‐1H coupling constants, 13C‐chemical shifts as well as 1H‐NMR data are reported (together with literature values). Substituent effects on the geminal and vicinal 13C‐1H coupling constants are discussed in terms of electronegativity, conformation and bond polarization.
The chemistry of small‐ring compounds. Part 40. Protonated and methylated methyleneaziridines
Authors: Jongejan E. , Steinberg H. , de Boer Th. J. 
Published: September 2010

AbstractThe N‐substituted methyleneaziridines 1a‐c are protonated on nitrogen without ring rupture by HFSO3/SbF5 in SO2 at − 78°C. NMR spectra remain unchanged up to + 50°C. Methylation of la does not take place with ordinary methylating agents but can be achieved with (CH3)2Cl⊕SbF5Cl⊖.
α‐Amino acid dehydrogenase models. Reduction of an imine and of iminium salts of α‐keto esters by 1,4‐dihydropyridines (Preliminary communication)
Authors: Pandit Upendra K. , de Nie‐Sarink Margreet J. , van der Burg Alida M. , Steevens Jan B. , van Dokkum Ronald F. M. 
Published: September 2010

Abstract3,5‐Di(ethoxycarbonyl)‐2,6‐dimethyl‐1,4‐dihydropyridine (Hantzsch ester) reduces imines (in the presence of Mg+ + ions) and iminium salts, derived from α‐keto esters.
The exchange of alkanediammonium ions in the zeolites X and Y
Authors: Vansant E. F. , Vanhoof L. 
Published: September 2010

AbstractA study has been made of the exchange properties of +H3N‐CH2‐NH+3, +H3N‐(CH2‐NH+3, +H3N‐(CH2)3‐NH+3, +H3N‐CH2‐CH(NH+3)‐CH3, +H3N‐(CH2)4‐NH+3, +H3N‐(CH2)5‐NH+3 and +H3N‐(CH2)6‐NH+3 in the zeolites X and Y.For steric reasons, none of the organic cations could effect a complete replacement of the Na+ ions initially present in the zeolite. A linear decrease and increase between the maximum extent of exchange and the molecular weight of the alkanediammonium ions were found for the zeolites X and Y, respectively. For any given alkanediammonium ion the maximum exchange capacity decreases with an increase in the affinity of the cations initially present in the zeolite, the order being Li+ > Na+ > K+. It is suggested that the localisation of the initial inorganic cations, influenced by the affinity of the ingoing organic cations and the difficulties of packing of the organic ions, controls the maximum extent of exchange.
Structure elucidation of the photo‐oxidation product of 1‐(9‐phenanthryl)‐4‐phenylbut‐1‐en‐3‐yne
Authors: van Arendonk R. J. F. M. , Laarhoven W. H. , Prick P. A. J. 
Published: September 2010

AbstractThe photo‐oxidation product of 1‐(9‐phenanthryl)‐4‐phenylbut‐1‐en‐3‐yne has been elucidated by chemical and spectroscopic methods (IR, UV, 1H‐NMR, 13C‐NMR) and independently by X‐ray analysis. The structure 6‐phenyl‐8,9‐10,11‐dibenzotricyclo[5.4.0.01,6]‐4‐oxaundeca‐2,8,10‐trien‐5‐one has a cyclopropapyrone unit which decomposes on thermolysis or by catalytic hydrogenation.
Recherches en série triazépine‐1,2,4 XIII. Hydrazinolyses de thioxo‐3 oxo(thioxo)‐5 triazépines‐1,2,4
Authors: Hasnaoui A. , Lavergne J.‐P. , Viallefont Ph. 
Published: September 2010

AbstractThe ring interconversion of 2,7‐dimethyl‐3‐thioxo‐5‐oxo(thioxo)‐1,2,4‐triazepines into pyrazolones, 3‐hydrazinopyrazoles or tetrazocyne by hydrazinolysis are described.The hydrazine and methylhydrazine reactions afforded 2‐methyl thiosemicarbazide and 3(5)‐pyrazolones by breaking of the two N(1)‐C(7) and N(4)‐C(5) bonds in the triazepinone ring. The reaction with phenylhydrazine is different. In this case three reaction centres must be taken into account: 3, 5 and 7 positions.Hydrazinolysis of 5‐thioxo‐1,2,4‐triazepine is more complicated and depends on the experimental conditions. The mechanism suggested is addition of two molecules of hydrazines in the 5 position followed by a transannular reaction to the 7 position for hydrazine and to the 3 and 7 position for phenylhydrazine.
Transsubstitution and equilibrium of phenols. Part III. Transbromination of phenols in the presence of aluminium phenoxide and other acidic catalysts
Authors: Jonkheer P. C. Th. M. , Moen J. , Wolters J. , Kooyman E. C. 
Published: September 2010

AbstractIntra‐ and inter‐molecular bromine migrations in bromophenols occur in the presence of catalytic amounts of aluminium phenoxides or proton acids (such as sulfuric and trifluoromethanesulfonic acid) at temperatures between 80 and 180°C. Under these conditions only ortho and para positions are involved; no meta‐bromophenols are formed.The equilibrium constants for the ortho‐ortho transsubstitution (Kx = [2‐bromo‐4‐X‐phenol]2/[2,6‐dibromo‐4‐X‐phenol] [4‐X‐phenol = 15 ± 3) are independent of substituents in the para position. The equilibrium constants for the ortho‐para isomerization are calculated (R2/4 = [2‐bromophenol]/[4‐bromophenol] = 1.9±0.3; R2,6/2,4 = [2,6‐dibromophenol]/[2,4‐dibromophenol] = 0.34± 0.04). Kinetic data ‐ some of them suggesting second‐order kinetics ‐ are given. A mechanism is proposed.
The solvent effect on the enthalpy of hydrolysis of cyclic adenosine 3′,5′‐monophosphate. A quantumchemical study
Authors: Scheffers‐Sap M. M. E. , Buck H. M. 
Published: September 2010

AbstractThe solvent effect on the enthalpy of hydrolysis has been studied by the Extended‐Hückel method for the hydrolysis reactions of cyclic adenosine 3′,5′‐monophosphate (cyclic 3′,5′‐AMP) and related cyclic phosphate diesters. The results show that the difference in enthalpy of hydrolysis between cyclic 3′,5′‐AMP and related phosphate diesters is explained by the difference in net solvation enthalpy. The larger exothermic net solvation enthalpy of cyclic 3′,5′‐AMP can be ascribed to an extra stabilization of the hydrolysis product with respect to the reactants, which does not occur for the other cyclic phosphate diesters. The extra stabilization is due to hydrogen bonding with water between O(1′) and O(5′) in both adenosine 5′ ‐ and 3′‐monophosphate.
Ring transformations in reactions of heterocyclic compounds with nucleophiles (XXI): Conversion of 5‐nitropyrimidine into pyridines and benzene derivatives by ketones
Authors: Barczyński P. , van der Plas H. C. 
Published: September 2010

AbstractReaction of 5‐nitropyrimidine with ketonic reagents such as acetone, diethyl ketone, dibenzyl ketone and acetylacetone in the presence of triethylamine or potassium ethoxide gave either the 5‐nitropyridine derivatives 1, the 4‐nitrophenol (2) or the 4‐pyridone (3). These reactions show the first examples of the conversion of a pyrimidine ring into a benzene ring. The reaction pattern strongly depends on the nature of the ketone and the base used. The mechanism of these ring‐transformation reactions involves the initial addition of the anion of the ketone to either C(6) (leading to 1 or 2) or C(2) (giving 3).
Selective photochemical isomerizations of E,E‐germacra‐1(10),4,7(11)‐trien‐8‐one
Authors: Reijnders Peter J. M. , Buck Henk M. 
Published: September 2010

AbstractDirect irradiation of title compound 1 causes isomerization of the 1(10)‐double bond to give the 1(10)Z,4E‐isomer 2, due to selective energy transfer in the β,γ‐enone fragment formed by the carbonyl group and the 1(10)‐double bond. Acetophenone‐sensitized irradiation in n‐hexane leads to the completely isomerized 1(10)Z,4Z‐germacrone 3. 1(10)E,4Z‐Germacrone could not be prepared photochemically.
Préparation de cyclobutanones substituées par l'intermédiaire de dérivés sulfurés
Authors: Paquer D. , Reffet D. , Vazeux M. 
Published: September 2010

AbstractSubstituted cyclobutanones have been obtained from the corresponding 1,3‐diones by converting one oxo group in the latter compounds into sulfur containing group(s) and subsequently removing the S group(s) with Raney‐Nickel. The mass spectral fragmentation patterns of these compounds are discussed.
Aspects of the amination of 4‐t‐butyl‐5‐halogenopyrimidines by potassium amide in liquid ammonia
Authors: Rasmussen C. A. H. , van Der Plas H. C. 
Published: September 2010

AbstractThe amination of 5‐bromo‐2,4‐di‐t‐butylpyrimidine (11b), 5‐chloro‐2,4‐di‐t‐butylpyrimidine (11c) and 4‐t‐butyl‐5‐chloropyrimidine (11a) on treatment with potassium amide in liquid ammonia has been studied. 11b yields 6‐amino‐2,4‐di‐t‐butylpyrimidine (7b) as major product. In contrast, 11c and 11a give 6‐amino‐5‐chloro‐2,4‐di‐t‐butylpyrimidine (12c) and 6‐amino‐4‐t‐butyl‐5‐chloropyrimidine (12a), respectively as main products, together with minor quantities of 7b and 6‐amino‐4‐t‐butylpyrimidine (7a). Choice of halogen and accessibility of C(2) of the pyrimidine nucleus influence the mechanism of the amination. An SN(ANRORC) mechanism is not operative in any of the conversions described.
Complex formation of adenine and 9‐methyladenine with transition metal salts in ethanol
Authors: Guichelaar M. A. , Reedijk J. 
Published: September 2010

AbstractThe coordination chemistry of adenine and 9‐methyladenine towards transition‐metal ions has been studied. Solid compounds of the formula M(AH)2X2 were isolated and characterised for M = Ni, Cu, Zn and Cd and X = Cl, Br, NO3 and ClO4; AH standing for adenine. With 9‐methyladenine (MA) solid compounds formulated as M(MA)X2(M = Co, Ni, Cu, Zn and Cd; X = Cl and Br) and formula M(MA)2(NO3)2‐nH2O (M = Co and Ni with n = 2 and M = Cu, with n = 1) have been synthesized.The compounds were characterised by chemical analysis, infrared spectra, far‐infrared spectra, ligand‐field spectra, X‐ray powder diagrams, ESR powder spectra and magnetic susceptibility measurements. Despite several attempts, no compounds containing more than two of these ligands per metal ion could be òbtained. Extensive ligand‐ligand and ligand‐anion hydrogen bonding may account for this result.With a few exceptions adenine appears to coordinate via N(9) in monomeric compounds and via N(3) and N(9) in dinuclear compounds. The respective coordination sites in 9‐methyladenine complexes are N(7) in the case of monodentate coordination, and N(1) and N(7) in the case of bidentate bridging coordination.
Catalytic inhibition of hydrocarbon autoxidation by secondary amines and nitroxides
Authors: Bolsman T. A. B. M. , Blok A. P. , Frijns J. H. G. 
Published: September 2010

AbstractA study has been made of the catalytic inhibition of the autoxidation of hydrocarbons at 130°C by secondary amines and derivatives thereof (hydroxylamines and nitroxides). Owing to a better resistance towards side‐reactions that cause decomposition of the inhibitor, certain dialkylamines are much more efficient than diarylamines. Some of the dialkylamines examined are capable of scavenging several hundreds of propagating radicals per molecule of inhibitor in autoxidizing alkanes and a few thousand radicals in autoxidizing n‐hexylbenzene.
Factors influencing the occurrence of an SN(ANRORC) mechanism in the amino‐dehalogenation of 4‐substituted 6‐halogenopyrimidines by potassium amide in liquid ammonia
Authors: Rasmussen C. A. H. , van der Plas H. C. 
Published: September 2010

AbstractEvidence is presented by means of 15N‐labelling that the occurrence of an SN(ANRORC) mechanism in the amino‐dehalogenation of 4‐substituted 6‐halogenopyrimidines by potassium amide in liquid ammonia is dependent on at least two factors. The C(2) position must be readily accessible to the attacking amide ion and the substituent at C(4) must not contain an acidic hydrogen atom adjacent to the pyrimidine nucleus. It is shown that the amount to which an SN(ANRORC) process occurs can be dependent on the reaction temperature.
Nitrogen fixation by reduced transition metal complexes. II. The influence of lithium and naphthalene as reducing species on vanadium trichloride
Authors: Beelen T. P. M. , Rummens C. P. J. 
Published: September 2010

AbstractVCl3 is able to bind dinitrogen at room temperature and a N2 pressure of 1 atmosphere after reduction with Li+Np− (Np = naphthalene) or with Li + Li+Np2−. In the latter case also a direct reaction of N2 with Li + Li2+Np2− occurs, so that there are two independent nitrogen fixation reactions effective in the system VCl3 + Li + Li2+Np2−. The role of Np2− ions in this system has been investigated and a proposal for the mechanism of the reaction of Li + Li2+Np2− with N2 is made.
3‐Methyl‐2‐chloro‐2‐hydroxy‐2‐phosphanaphthalene. A stable p‐hydroxy‐λ5‐phosphorin
Authors: Klebach Th. , Jongsma C. , Bickelhaupt F. 
Published: September 2010

Abstract3‐Methyl‐2‐chloro‐2‐hydroxy‐2‐phosphanaphthalene (3) is obtained from the dihydroprecursors 6 and 14 by treatment with COCl2 followed by triethylamine. Contrary to other P‐hydroxy‐λ5‐phosphorins, 3 is thermally surprisingly stable. Protons catalyze its rearrangement to the thermodynamically more stable isomer 3‐methyl‐2‐chloro‐1,2‐dihydro‐2‐phosphanaphthalene 2‐oxide (5). Some aspects of the formation of 3 are discussed.