Asymmetric Reductive Amination/Ring-Closing Cascade: Direct Synthesis of Enantioenriched Biaryl-Bridged NH Lactams
Yao Zhang1,2, Yun-Qi Liu1, Le'an Hu1
1Guangdong Provincial Key Laboratory of Catalysis, Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China.
Abstract:
We report here a Ru-catalyzed enantioselective synthesis of biaryl-bridged NH lactams through asymmetric reductive amination and a spontaneous ring-closing cascade from keto esters and NH4OAc with H2 as reductant. The reaction features broad substrate generality and high enantioselectivities (up to >99% ee). To showcase the practical utility, a highly enantioselective synthesis of 5-ethylindolobenzazepinone C, a promising antimitotic agent, has been rapidly completed. Furthermore, the amide group in the products enables versatile elaborations through directed C-H functionalization.
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