Palladium(II)-Catalyzed Intramolecular Tandem Aminoalkylation via Divergent C(sp3)–H Functionalization

Abstract

We have developed a Pd(II)-catalyzed oxidative tandem aminoalkylation via divergent C(sp3)–H functionalization, affording three- and five-membered-ring fused indolines in good yields under two optimized conditions, respectively. The mechanism studies have indicated that the benzylic C–H cleavage involved in the former transformation is the rate-determining step, while the cleavage of amide α-C–H in the latter is not. This is the first example of a Pd-catalyzed tandem reaction involving C(sp3)–H activation without the employment of prefunctionalized reagents (e.g., halogenated and boron reagents) and directing groups, representing a green and economic protocol for the construction of N-containing heterocycles.