Visible-light-induced organocatalyzed C(sp2)-H bond functionalization of 1,3-azoles with trifluoroacetylsilanes
摘要
Previous carbene insertion to C-H bonds of 1,3-azoles relied on metal carbene species. Herein, we report a metal-free C(sp2)-H bond functionalization of 1,3-azoles with trifluoroacetylsilanes. The reaction features mild conditions, broad substrate scope and wide functional group tolerance. The mechanistic study supports that the success of the reaction is probably attributed to the dual roles of trifluoroacetylsilanes under the photocatalyzed conditions: generating carbenes which undergo cyclopropanation and generating biradicals which promote ring-opening aromatization of the in situ generated fused cyclopropanes.