Boron-Catalyzed Silylative Reduction of Quinolines: Selective sp3 C–Si Bond Formation
journal contributionposted on 03.12.2014, 00:00 by Narasimhulu Gandhamsetty, Seewon Joung, Sung-Woo Park, Sehoon Park, Sukbok Chang
A silylative reduction of quinolines to synthetically versatile tetrahydroquinoline molecules involving the formation of a C(sp3)–Si bond exclusively β to nitrogen is described. Triarylborane is a highly efficient catalyst (up to 1000 turnovers), and silanes serve as both a silyl source and a reducing reagent. The present procedure is convenient to perform even on a large scale with excellent stereoselectivity. Mechanistic studies revealed that the formation of a 1,4-addition adduct is rate-limiting while the subsequent C(sp3)–Si bond-forming step from the 1,4-adduct is facile.