Incorporation of Carbon Dioxide into Carbamate Directing Groups: Palladium-Catalyzed meta-C-H Olefination and Acetoxylation of Aniline Derivatives

摘要

Carbon dioxide (CO2), a readily available, non-toxic, and inexpensive greenhouse gas, is an ideal reagent for carbamate synthesis. For the first time, CO2 has been efficiently incorporated into a novel nitrile-containing directing group (DG) for meta-C-H activation of anilines under mild conditions. Thus, various aniline derivatives were metaolefinated with palladium(II) acetate. meta-C-H acetoxylation was also feasible and the carbamate DG could be easily removed under basic conditions. The practicality of substrate preparation, functional group tolerance, and versatility of this method make it a valuable addition to the meta-C-H functionalization of anilines.