Visible-light-driven gem-difluorocyclopropanation of gem-difluoroalkenes with diazo compounds

A highly efficient approach is outlined for gem-difluorocyclopropanation of diazo compounds utilizing visible light catalysis. This method is distinguished by its mild reaction conditions, operational simplicity, broad substrate scope, excellent diastereoselectivity and exceptional synthetic efficacy. Notably, the synthesis of gem-difluorocyclopropanes is achieved without the necessity of transition metal catalysis or photocatalysts. In contrast to traditional methods of gem-difluorocyclopropane synthesis, this method allows for the direct synthesis of various sterically hindered gem-difluorocyclopropanes in a single step under mild conditions, while also demonstrating outstanding stereoselectivity.