Catalyst-Free and Solvent-Controlled Divergent Synthesis of Difluoromethylene-Containing S-Heterocycles

An unprecedented catalyst-free reaction of benzo[b]thiophene-2,3-diones with difluoroenoxysilanes has been developed using either MeOH or H2O as the solvent, which constitutes a facile and efficient protocol for the solvent-controlled divergent synthesis of five- and seven-membered S-heterocycles featuring a gem-difluoromethylene group. A gram-scale synthesis and the diversification of the product transformations to other difluorinated S-heterocycles further highlight its utility.

Automated summary

An unprecedented catalyst-free reaction has been developed for the synthesis of S-heterocycles featuring a gem-difluoromethylene group, using either MeOH or H2O as the solvent. The gram-scale synthesis and the diversification of product transformations further demonstrate the utility of this method.