Synthesis of 3,4-Disubstituted 1,2,3,4-Tetrahydroquinoline Thiocyanates Based on Thiocyanation-Cyclization of <i<N</i<-Cinnamyl Sulfonamides

Compounds containing other important functional groups can be synthesized by the functionalization conversion reactions of olefins, such as halogenated compounds, sulfur trifluoromethyl compounds and selenophenyl compounds.It is difficult to synthesize thiocyanates based on the formation of new C-C bonds from olefins.In this study, a thiocyanation-cyclization method of <i<N</i<-cinnamyl sulfonamides was developed to prepare 3,4-disubstituted 1,2,3,4-tetrahydroquinoline thiocyanates by constructing a new C-C bond in hexafluoroisopropanol (HFIP) with zinc chloride existence.The reaction conditions were mildly arranged with high yield and high regio-selectivity,and a new free radical mechanism was proposed based on the newly discovered cationic thiocyano reagent (<i<N</i<-thiocyanosaccharin).