the kinetics of the reactions between triphenylphosphine 1 and dialkyl acetylenedicarboxylates 2, in the presence of a nh-acid such as 5-nitroindazole 3,were studied. corresponding kinetic parameters to all reactions were evaluated, with the second order rate constant (k) values calculated. effects of solvent, temperature, and reactants (dialkyl acetylenedicarboxylates) structure and concentrat...

in order to investigate the effects of dimethylamino substituent at postion 2 of the dihydropyridine nucleus on its activity, dialkyl 1,4-dihydro-2-[2-(dimethy- lamino) ethyl]-6-methyl-4-(1-benzyl-2-alkylthio-5-imidazolyl)-3,5-pyrdinedicar- boxylates (6a-f) were synthesized. the synthesis was started from dialkyl 1,4- dihydro-2,6-dimethyl-4-(1-benzyl-2-alkylthio-5-imidazolyl)-3,5-pyridinedicar-...

Stable crystalline phosphorus ylides are obtained in excellent yields from the 1:1:1 addition reactionbetween hydantoins or thiohydantoins and dialkyl acetylenedicarboxylates in the presence oftriphenylphosphine. These phosphoranes undergo smooth intramolecular Wittig reaction followedby an electrocyclic ring opening to produce dialkyl (E)-2-(2,5-dihydro-5,5-diaryl-2-thioxo-1H-imidazol-4-yl)fum...

The 1:1 reactive intermediates produced in the reaction between alkyl isocyanides and dialkyl acetylenedicarboxylates were trapped with 2-thioxothiazolidin-4-one to generate to highly functionalized ketenimines. A series of new 2-thioxothiazolidin-4-one derivatives were synthesized in moderate yields. The advantages of the present method include good functional group tolerance and simple experi...

Abstract The one‐bond nucleophilic reactivities of seven cyclic α‐diazo carbonyl compounds in dichloromethane were determined by analyzing the kinetics their reactions with benzhydrylium ions (one‐bond reference electrophiles) at 20 °C according to Mayr‐Patz equation. Though not calibrated for pericyclic reactions, identified nucleophilicities also reflect relative 1,3‐dipolar cycloadditions di...