Iron-Catalyzed Esterification of Benzyl C-H Bonds to Form α-Keto Benzyl Esters

An atom-economic and efficient non-precious metal-catalyzed esterification of benzyl C-H bonds has been developed. A variety of a-keto benzyl esters have been accessed in good yields through the reactions between benzyl derivatives and benzoylformic acids using iron trifluoride as a catalyst in the presence of di-tert-butyl peroxide under an inert atmosphere. This strategy provides a straightforward access to linearly expanded alpha-keto benzyl esters. A plausible reaction mechanism is proposed.