Enantioselective Benzoyloxylation of Aldehydes

Significance

Maruoka and co-workers report the direct asymmetric benzoyloxylation of aldehydes with benzoyl peroxide using 2-tritylpyrrolidine as efficient catalyst. Catalytic amounts of hydroqui-none were found to be crucial for increased yields. The authors discuss two mechanisms, one involving the N-benzoylation of the enamine intermediate followed by a 1,3-rearrangement (path A). ­Another possible mechanism proceeds via direct C-O bond formation between enamines and benzoyl peroxide (path B).