Aerobic oxidative cyclization under Pd(II) catalysis: a regioselective approach to heterocycles.

[chemical reaction: see text]. An efficient Yb(OTf)3-promoted palladium-catalyzed oxidative cyclization of gamma-heteroalkenyl beta-keto amides has been developed. Under simple aerobic condition, a variety of six-, seven-, and eight-membered-ring N- and O-heterocycles were obtained regioselectively in excellent yield.