Bidentate Ru(II)-NC Complexes as Catalysts for alpha-Alkylation of Unactivated Amides and Esters

Five Ru(II)-NC complexes were tested as catalysts for alpha-alkylation of unactivated amides using alcohols as alkylating agents, and complex {(C5H4N)-(C6H4)}RuCl(CO)(PPh3)(2) (1) showed the highest activity. With 0.5 mol% catalyst loading, a series of alpha-alkylated amides were isolated at 80 degrees C within 6 hours. Furthermore, under similar conditions, complex 1 was also active for alpha-alkylation of unactivated esters with alcohols, and the reaction time was shortened to 1.5 hours. The catalytic performance of 1 is comparable to the best reported catalyst.