Trimethylsilyl chloride assisted conjugate addition-elimination of organocopper reagents to 2-bis(methylthio)nitroethylene: an efficient and highly stereoselective synthesis of 2-methylthio-2-alkyl/aryl-1-nitroethylenes and their application for synthesis of nitroheterocycles

Abstract

An efficient method for the synthesis of novel 2-methylthio-2-alkyl/aryl-1-nitroethylenes 2 has been developed via conjugate addition-elimination of organocopper reagents to nitroketene dithioacetal 1 in the presence of TMSCl. The product nitroethylenes 2 have been further utilized for the synthesis of substituted 3-nitro-2-alkyl/arylpyrroles 5 by their reaction with aminoacetaldehyde dimethylacetal followed by acid catalyzed cyclization in ethereal HCl. The reaction of 2 with propargyl alcohol has also been investigated.