Highly Efficient Syntheses of Azetidines, Pyrrolidines, and Indolines via Palladium Catalyzed Intramolecular Amination of C(sp3)–H and C(sp2)–H Bonds at γ and δ Positions
journal contributionposted on 11.01.2012, 00:00 by Gang He, Yingsheng Zhao, Shuyu Zhang, Chengxi Lu, Gong Chen
Efficient methods have been developed to synthesize azetidine, pyrrolidine, and indoline compounds via palladium-catalyzed intramolecular amination of C–H bonds at the γ and δ positions of picolinamide (PA) protected amine substrates. These methods feature relatively a low catalyst loading, use of inexpensive reagents, and convenient operating conditions. Their selectivities are predictable. These methods highlight the use of unactivated C–H bond, especially the C(sp3)–H bond of methyl groups, as functional groups in organic synthesis.