Nano Silica Powder Catalyzed STEREOSELECTIVE C-Vinylation of Diphenylacetonitril

β-Addition of nucleophiles to the vinyl group of vinilic phosphonium salt leading to the formation of new alkylidene phosphoran has attracted much attention as a very convenient and synthetically useful method in organic synthesis. In recent years, we have established a convenient, one-pot method for preparation of the phosphonium salt 1 . In this article, we report facial one-pot stereoselective synthesis of dialkyl(Z)-2[cyano(diphenyl)methyl]-2- butenedioates in fairly high yields under thermal and microwave conditions in solvent-less system (SCHEME 1). The ylide 5 may result from initial addition of triphenylphosphine 1 to the acetylenic ester 2 and concomitant protonation of the 1:1 adduct, followed by the electrophilic attack of the vinyltriphenylphosphonium cation to the carbanion 4 (SCHEME 1). TLC indicated formation of ylides 5 in CH2Cl2 .Nano Silica powder was found to catalyze conversion of the stabilized phosphorus ylides 5 to dialkyl(Z)-2-[cyano(diphenyl)methyl]-2-butenedioates 6 under thermal conditions in solvent-less system.