立体中心
废止
炔烃
铑
催化作用
化学
位阻效应
立体化学
对映选择合成
组合化学
有机化学
作者
Chao Yang,Lijun Shi,Fang Wang,Yijin Su,Ji‐Bao Xia,Fuwei Li
出处
期刊:ACS Catalysis
[American Chemical Society]
日期:2022-11-04
卷期号:12 (22): 14194-14208
被引量:10
标识
DOI:10.1021/acscatal.2c04373
摘要
N-Fused 5/7-membered bicycles have witnessed apparent importance in many bioactive molecules, but there are rare examples to construct these privileged scaffolds by asymmetric catalysis due to the unfavorable steric hindrance, transannular interactions, and congested bridgehead stereocenter. We herein report rhodium-catalyzed (3 + 2 + 2) annulation of alkenylamides with alkynes for the efficient synthesis of stereogenic 1-azabicyclo[5.3.0]decanes through N–H/C–H bond dual activation. Moreover, the corresponding asymmetric catalytic reaction has been realized leading to enantioenriched products bearing bridgehead quaternary stereocenter in moderate-to-good yields with up to 96% ee. Mechanistic studies and density functional theory calculations have revealed that rhodium experienced a preset unique catalytic pathway via amino rhodation of tethered ene to produce a stereogenic alkyl-Rh species, which undergoes the following C–H activation and alkyne insertion to provide the key 8-membered rhodacycle intermediate. This protocol discloses a highly valuable asymmetric rhodium-mediated C–H functionalization mode and validates a de novo cascade construction of chiral 1-azabicyclo[5.3.0]decanes.
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