Palladium-catalyzed intramolecular dearomatization of indoles via Heck/Stille cross-coupling with organostannanes

Abstract

A palladium-catalyzed tandem intramolecular Heck cyclization/intermolecular Stille coupling for the dearomatization of N-(2-bromobenzoyl)indoles is described. This organotin-based protocol provides fused indoline derivatives bearing contiguous quaternary carbon stereocenters at the C2 and C3 positions in moderate to excellent yields and is compatible with structurally diverse organotin reagents, including aryl-, naphthyl-, vinyl ether-, alkenyl-, and alkyl-substituted stannanes. Moreover, this protocol is characterized by mild conditions and gram-scale scalability.