Reactivities of α-Oxo BMIDA Gold Carbenes Generated by Gold-Catalyzed Oxidation of BMIDA-Terminated Alkynes

An oxidative strategy is reported to access alpha-oxo BMIDA gold carbenes directly from BMIDA-terminated alkynes. Besides offering expedient access to seldom studied boryl metal carbenes, these BMIDA gold carbene species undergo facile insertions into methyl, methylene, methine, and benzylic C-H bonds in the absence of the Thorpe-Ingold effect. They also undergo efficient OH insertion, cyclopropanation, and F-C alkylations. This chemistry provides rapid access to structurally diverse alpha-BMIDA ketones, which are scarcely documented. In combination with DFT studies, the role of BMIDA is established to be an electron-donating group that attenuates the high electrophilicity of the gold carbene center.

Automated summary

An oxidative strategy is reported for the direct access of alpha-oxo BMIDA gold carbenes from BMIDA-terminated alkynes. These BMIDA gold carbene species can insert into various C-H bonds and undergo other reactions, leading to the formation of structurally diverse alpha-BMIDA ketones. The role of BMIDA is found to be an electron-donating group that reduces the electrophilicity of the gold carbene center, as supported by DFT studies.