Utilization of phenylthio substituted amines for the synthesis of pyrrolidines

Abstract

Abstract α‐Phenylthio substituted amines [ 2, 10, 17, 26 , and 39 ] have been found to be convenient reagents for the preparation of the pyrrolidine ring. Benzyl[(phenylthio)methyl][(trimethylsilyl)methyl]amine ( 2 ) undergoes 1,3‐dipolar cycloaddition with several dipolarophiles in the presence of silver fluoride. The reaction is believed to proceed via the intermediacy of an azomethine ylide. Treatment of α‐(phenylthio)cyanoamines 10 and 17 with strong base results in the loss of the phenylthio group, and formation of substituted trans ‐piperazines 21, 22 in the case of 17 . The mechanism of the reaction involves dimerization of the initially formed cyano substituted azomethine ylide intermediate, which behaves as a captodative diradical. Finally, the reaction of several alkenyl[(phenylthio)methyl]amines with tributyltin hydride was studied as a method for generating the pyrrolidine ring via a radical cyclization reaction.