Diastereoselectivity in reactions of aryl-stabilised ammonium ylides are highly sensitive to the nature of the amine and the ylide substituent. DFT calculations are consistent with a mechanism in which reversibility in betaine formation [despite the high energy (and therefore instability) of ammonium ylides] is finely balanced due to the high barrier to ring closure.

Readily available poly(sulfur ylides) are described as a new class of zwitterionic polymers that show distinct solution and thermal behavior.

The reaction between vinylene trithiocarbonate and chlorosulfonyl isocyanate proceeds by initial attack of thiocarbonyl on the isocyanate carbon.

A [3+2] cycloaddition (32CA) reaction among a thiocarbonyl ylide (TCY 2) with (E)-4,4,4-trifluoro-4-phenylbut-3-en-2-one (TFB 4) as an electron-deficient enone in tetrahydrofuran (THF) were studied within the Molecular Electron Density Theory (MEDT), at the DFT-B3LYP/6-31G(d) computational level to analysis energetics, selectivities, and mechanistic aspects. The reaction can progress in four co...

Ultrasound irradiation can promote the 1,3-dipolar cycloaddition reaction of 2-chloropyridinium ylides with 2-benzylidenemalononitrile or 2,2'-(1,4-phenylenebis(methanylylidene))dimalononitrile, to afford the indolizine and bis-indolizine derivatives respectively. While the reaction of pyridinium ylides with 2-benzylidenemalononitrile or 2,2'-(1,4-phenylenebis(methanylylidene))dimalononitrile u...

The three possible structural isomers of 4-(pyridyl)pyrimidine were employed for the synthesis of new pyrrolo[1,2-c]pyrimidines and new indolizines, by 1,3-dipolar cycloaddition reaction of their corresponding N-ylides generated in situ from their corresponding cycloimmonium bromides. In the case of 4-(3-pyridyl)pyrimidine and 4-(4-pyridyl)pyrimidine the quaternization reactions occur as expect...

The experimental results of the reaction of C60 with carbonyl ylides generated from trans-epoxides, which afforded cis-products exclusively or predominantly, can be explained well by computational investigation of the proposed reaction mechanism. Our theoretical calculations demonstrate that only cis-carbonyl ylides can be formed directly from trans-epoxides, in compliance with the Woodward-Hof...

The cis-trans ratio of the alkenes formed in Wittig reactions of semistabilised ylides (derived from benzyltriarylphosphonium salts in ethanolic sodium ethoxide) with benzaldehyde, acetaldehyde or trimethylacetaldehyde increases as steric crowding at phosphorus increases. In contrast, the cis-trans ratio of the unsaturated esters formed in the related reactions of the stabilised ethoxycarbonylm...

A highly reactive Ag(I)-catalyzed [3 + 2] cycloaddition of azomethine ylides is founded using AgOAc as the catalytic precursor and phosphines as ligands. Using a new bis-ferrocenyl amide phosphine (FAP) as the ligand, we found that high enantioselectivities (up to 97% ee) have been achieved in the [3 + 2] cycloaddition of azomethine ylides. Up to four stereogenic centers can be established in t...