Synthetic applications of Pd(II)-catalyzed C-H carboxylation and mechanistic insights: expedient routes to anthranilic acids, oxazolinones, and quinazolinones.

摘要: A Pd(II)-catalyzed reaction protocol for the carboxylation of ortho-C-H bonds in anilides to form N-acyl anthranilic acids has been developed. This procedure provides a novel and efficient strategy rapid assembly biologically pharmaceutically significant molecules, such as benzoxazinones quinazolinones, from simple without installing removing an external directing group. The conditions are also amenable N-phenyl pyrrolidinones. monomeric palladacycle containing p-toluenesulfonate anionic ligand characterized by X-ray crystallography, crucial role p-toluenesulfonic acid activation C-H presence carbon monoxide is discussed. Identification two key intermediates, mixed anhydride benzoxazinone formed reductive elimination organometallic Ar(CO)Pd(II)-OTs species, mechanistic evidence dual-reaction pathway.