Boron-Catalyzed Hydrogenative Reduction of Substituted Quinolines to Tetrahydroquinolines with Hydrosilanes
Narasimhulu Gandhamsetty, Sehoon Park*, Sukbok Chang*
*Department of Chemistry, Korea Advanced Institute of Science & Technology (KAIST), Daejeon 305-701, South Korea, Email: sehoonpkaist.ac.kr, sbchangkaist.ac.kr
N. Gandhamsetty, S. Park, S. Chang, Synlett, 2017, 28, 2396-2400.
DOI: 10.1055/s-0036-1588442 (free Supporting Information)
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B(C6F5) enables a metal-free hydrogenative reduction of substituted N-heteroaromatics using hydrosilanes as reducing agents. The optimized conditions were successfully applied to quinolines, quinoxalines, and quinoline N-oxides. The initial step in the catalytic cycle involves 1,4-addition of the hydrosilane to the quinoline to give a 1,4-dihydroquinoline followed by (transfer) hydrogenation to deliver the tetrahydroquinoline.
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