Rh(III)‐catalyzed C6‐selective Acylmethylation and Carboxymethylation of 2‐Pyridones with Diazo Compounds

Abstract

AbstractChelation‐assisted C6‐selective acylmethylation and carboxymethylation of 2‐pyridones with diazo carbonyl compounds under [Cp*RhCl2]2/AgSbF6 catalysis have been developed. Deesterificative C6‐acylmethylation of 2‐pyridones with diazo tert‐butyl ester compounds proceeds effectively with the use of HOAc additive and hexafluoroisopropanol (HFIP) solvent, whereas switching to NaOAc additive and MeOH solvent enables efficient deacylative C6‐carboxymethylation of 2‐pyridones with alkyl 2‐diazo‐3‐oxobutanoates. The procedures are characterized by excellent regioselectivity, high efficiency, broad substrate scope, wide functional group compatibility and gram‐scalability. Preliminary mechanistic experiments are conducted to gain insights into the reaction mechanisms.