Studies On [3+2]Cycloadditions Reaction Of α-Oxo Ketene Dithioacetal With The Propargyl Amine

Functionalized a-oxo ketene dithioacetals are versatile intermediates in organic synthesis. Due to activation fuction of carbonyl and alkylthio of α-oxo ketene dithioacetals. Electronic cloud density of α-C is high, can be used as a nucleophilic center reaction, β-C as a electrophilic center of reaction. One of the most important use is in can be associated with a variety of having a nucleophilic reaction of the material, what can synthesize a variety of heterocyclic compounds. In addition, Propargyl amine has a nucleophilic nitrogen atoms. And, C-C triple bond has high density of electron cloud and the formation of tube-shaped distribution between the C-C, carbon nuclear attract electrons not firmly and electronic flow easily, the uneven distribution of electronic between C-C and II electronic can easily polarized.This special structure determine that the C-C triple bond can take nucleophilic addition reactions and can also occur electrophilic addition.Based on the features of the a-oxo ketene dithioacetal and propargyl amine to synthesize the target product. Though continuous reaction:the nitrogen atom of propargyl amine and the α-C of α-oxo ketene take nucleophilic addition elimination reaction, via deacylative [3+2] cycloaddition reaction to preparate2,3,4-trisubstituted pyrroles. On this base, we studied the reaction of the α-oxo ketene dithioacetal and N-methylprop-2-yn-1-amine, via a formal1,2-acyl migrating cycloaddition reaction to preparate1,2,3,4-tetrasubstituted pyrroles compounds. The work of this paper include the following:1:We synthesized2,3,4-trisubstituted pyrroles compounds via the reaction of the α-oxo ketene dithioacetal and the propargyl amine.2:We synthesized1,2,3,4-tetrasubstituted pyrroles compounds via the reaction of the α-oxo ketene dithioacetal and the N-methylpropargyl amine.In this paper,23compounds were synthesized and confirmed by1H NMR and13C NMR spectroscopies, etc.