Showing papers on "Ylide published in 1971"
TL;DR: The mode of bonding of cyclopropane to platinum is described through a crystal structure determination of the complex [PtCI2(C5H5N)2C3H6] as discussed by the authors.
62 citations
60 citations
37 citations
31 citations
TL;DR: Acylmethylenetriphenylphosphoranes react with aryl azides in refluxing benzene to give 1-aryl-5-substituted-1,2,3-triazoles exclusively.
30 citations
TL;DR: 2,3-Diphenylindenone oxide 1 undergoes thermal 1, 3-dipolar cycloadditions via a carbonyl ylide with symmetrical olefinic dipolarophiles to give (i) with cis addends mixtures of endo and exo adducts...
Abstract: 2,3-Diphenylindenone oxide 1 undergoes thermal 1,3-dipolar cycloadditions via a carbonyl ylide with symmetrical olefinic dipolarophiles to give (i) with cis addends mixtures of endo and exo adducts...
24 citations
TL;DR: The title reaction of carbonyl-stabilized sulphonium ylides 1a−1g with diphenylcyclopropenone (2) gives 2-pyrone derivatives 3a−3g under elimination of the sulphide at room temperature as mentioned in this paper.
23 citations
TL;DR: Trans-and cis-Dicyanostilbene oxides establish an equilibrium at 100-120° via carbonyl ylides as mentioned in this paper, and the intermediate is a 1,3-dipole and undergoes cycloadditions with a variety of acetylenic and olefinic dipolarophiles.
Abstract: trans- and cis-Dicyanostilbene oxides establish an equilibrium at 100–120°via carbonyl ylides; the carbonyl ylide intermediate is a 1,3-dipole and undergoes cycloadditions with a variety of acetylenic and olefinic dipolarophiles.
16 citations
16 citations
TL;DR: In this paper, the first two bands of 1-ethoxycarbonylimino-pyridinium ylide were assigned to π* π transitions, and the photorearrangement of 1 leading to the diazepine 3 was discussed.
Abstract: The UV. spectrum of 1-ethoxycarbonylimino-pyridinium ylide 1 has been measured using the stretched film technique. From a Pariser-Parr-Pople model the first two bands can be assigned to π* π transitions. The photorearrangement of 1 leading to the diazepine 3 is discussed.
14 citations
TL;DR: In this article, the ylide of 2,2′-diaminobiphenyl with pentyl nitrite or N-nitrosodiphenylamine was shown to yield benzocinnoline and nitrene on photolysis or thermolysis.
Abstract: Treatment of 2,2′-diaminobiphenyl with pentyl nitrite or N-nitrosodiphenylamine gives the ylide (2; R = H), possibly via the triazepine (1; R = H); N-substituted derivatives also exist as the ylide (2) rather than the triazepine (1), and yield benzocinnoline and the nitrene (R–N:) on photolysis or thermolysis.
TL;DR: In this article, the effect of solvent polarity on the first absorption bands of the two types of compounds was studied, and the comparative stabilities of ylides and anhydro-bases were investigated by measuring the rates of deuterium exchange of six C-benzyl-1,2,4-triazolium salts.
Abstract: Deprotonation of two N-p-nitroanilino-1,2,4-triazolium salts gave stable triazole-N-imines(triazolio-anilides), which underwent protonation, alkylation, and acetylation at the exocyclic nitrogen atom. Treatment of 3-p-nitrobenzyl- and 3-(2,4-dinitrobenzyl)-1,2,4-triazolium perchlorates with sodium ethoxide yielded deeply coloured triazolium C-ylides (16) of varying stability; a triazolo[1,5-a]pyridinium ylide (18) was prepared similarly. Coloured 1,2,4-triazole anhydrobases (5-methylene-Δ2-1,2,4-triazolines)(23) were obtained by proton abstraction from triazolium salts bearing nitrobenzyl-substituents at C-5. Deprotonation of 3,5-di-p-nitrobenzyl-1,4-diphenyl-1,2,4-triazolium perchlorate (22c) occurs from the 5-methylene group to yield the triazoline (23c). The ylides and anhydrobases react reversibly with water to form colourless triazolium hydroxides. The effect of solvent polarity on the first absorption bands of the two types of compounds was studied. The comparative stabilities of ylides and anhydro-bases were investigated by measuring the rates of deuterium exchange of six C-benzyl-1,2,4-triazolium salts. The anomalous properties of 5-(2,4-dinitrobenzylidene)-1,3,4-triphenyl-Δ2-1,2,4-triazoline (23b) are attributed to a steric effect.
TL;DR: In this paper, the preparation of the Dimethylselenononium ylide 2 of Meldrum's acid, together with some of its spectral data, is described.
TL;DR: In this article, the authors describe the Pummerer rearrangement of the 2,5-di-O-acetyl-1,4:3,6-bis(thioanhydro)-D-iditol-disulfoxide (1) isomers, which can be formed only by addition of acetic anhydride to an ylide interintermediate.
TL;DR: The crystal and molecular structure of the reaction product of (Ph3P)2C and Mn(CO)5Br has been determined and the complex found to contain the unusual phosphonium acetylide, Ph3P+−CC:− as discussed by the authors.
Abstract: The crystal and molecular structure of the reaction product of (Ph3P)2C and Mn(CO)5Br, [Mn(CO)4(C2PPh3)Br], has been determined and the complex found to contain the unusual phosphonium acetylide, Ph3P+–CC:–.
TL;DR: The thermal reaction of the pyridinium ylides (VII) results in cyclization followed by dehydrogenation to pyrazolo[1,5a]pyridines (IX) as mentioned in this paper.
Abstract: The thermal reaction of the pyridinium ylides (VII) results in cyclization followed by dehydrogenation to pyrazolo[1,5-a]pyridines (IX).
TL;DR: The intermediacy of a carbonyl ylide is used to explain why treatment of benzaldehyde with phenyl(bromodichloromethyl)mercury produced phenylmercuric bromide, carbon monoxide, benzal halide, and methyl 2,4-diphenyl-3,5-dioxahexanoate as major products as mentioned in this paper.
Abstract: The intermediacy of a carbonyl ylide is used to explain why treatment of benzaldehyde with phenyl(bromodichloromethyl)mercury produced phenylmercuric bromide, carbon monoxide, benzal halide, and methyl 2,4-diphenyl-3,5-dioxahexanoate as major products.
TL;DR: In this paper, it was shown that the thermal decomposition of diazo-2,3,4-triphenylcyclopentadiene in the presence of carbene acceptors was not a satisfactory method for the preparation of triphenyl-cyclopentadienylides.
Abstract: Thermal decomposition of diazo-2,3,4-triphenylcyclopentadiene in the presence of carbene acceptors was not a satisfactory method for the preparation of triphenylcyclopentadienylides. Pyridinium and phosphonium ylides were made by modified salt methods, and an arsonium ylide by a condensation reaction with triphenylarsine oxide.
TL;DR: In this article, an intermediate product of the reaction seems to be the ylide 6, which can be isolated, and the synthesis of 4-arylthiopyrazolone, thiophenols and DMSO is described.
Abstract: Aus Phenylmethylpyrazolon, Thiophenolen und DMSO werden die Titelverbindungen dargestellt, deren Entstehung uber das isolierbare Ylid 6 wahrscheinlich gemacht wird.
Synthesis of 1-Phenyl-3-methyl-4-arylthiopyrazol-5-ones
Synthesis of 4-arylthiopyrazolones from phenylmethylpyrazolone, thiophenols and DMSO is described. An intermediate product of the reaction seems to be the ylide 6, which can be isolated.
TL;DR: In this article, it was shown that anionic or ylide intermediates similar to those involved in these exchanges are involved in the biosynthesis of uridylic acid, and the change in mechanism for C-2 HD exchange from direct proton removal for 1-methyl-4-pyridone (1) to addition-elimination for 3 is intelligible in terms of the relative kinetic acidities of the free base and the corresponding 'onium salt for each case.
TL;DR: In this article, a crystal structure analysis of triphenylarsonium 2-Acetyl-3,4,5-triphenylcyclopentadienylide has been carried out and it has been shown that a dipolar form with an As+⋯O-interaction makes a significant contribution to the ground-state structure.
Abstract: Molecular dimensions found in a crystal structure analysis of triphenylarsonium 2-Acetyl-3,4,5-triphenylcyclopentadienylide establish that a dipolar form with an As+⋯O– intramolecular interaction makes a significant contribution to the ground-state structure.
TL;DR: In this article, it was shown that the reaction of phenyldichlorobromomethylmercury with benzophenone results in the formation of carbon monoxide, dichlorodiphenylmethane, and chlorodevinylacetyl chloride.
Abstract: Evidence is presented that the reaction of phenyldichlorobromomethylmercury with benzophenone results in the formation of carbon monoxide, dichlorodiphenylmethane, and chlorodiphenylacetyl chloride, and that the reaction may involve the intermediacy of a complex between the mercurial and the benzophenone in addition to a carbonyl ylide and/or a dichloro-oxiran.
TL;DR: The base-catalysed rearrangement of the ammonium bromide (1) gives a mixture of the allene (3) and the ylide (5); the implications of this result are discussed as mentioned in this paper.
Abstract: The base-catalysed rearrangement of the ammonium bromide (1) gives a mixture of the allene (3) and the ylide (5); the implications of this result are discussed.
TL;DR: In this article, the ylide was shown to be the vinyl sulphide, and the mechanism of its formation was found to involve a stereospecific Ylide-salt coupling process.
Abstract: The compound previously described as the ylide (2) is now shown to be the vinyl sulphide (6); the mechanism of its formation is shown to involve a stereospecific ylide–salt coupling process.
TL;DR: The sulphonium salt (VII) when exposed to base is cleanly rearranged to the sulphide (IX) even at −40°, indicating that extensive delocalisation of the intermediate ylide is insufficient to prevent the sigmatropic rearrangement as mentioned in this paper.
Abstract: The sulphonium salt (VII) when exposed to base is cleanly rearranged to the sulphide (IX) even at –40°, indicating that extensive delocalisation of the intermediate ylide is insufficient to prevent the sigmatropic rearrangement.