An Asymmetric Hydrogenation/N‐Alkylation Sequence for a Step‐Economical Route to Indolizidines and Quinolizidines

作者：Wei Zhao, Wenji Wang, Huan Zhou, Qishan Liu, Zhiqing Ma, Haizhou Huang, Mingxin Chang · 发表于：Angewandte Chemie International Edition · 年份：2023 · DOI：10.1002/anie.202308836 · 被引用次数：14 · 研究领域：Asymmetric Hydrogenation and Catalysis、Surface Chemistry and Catalysis、Asymmetric Synthesis and Catalysis

The direct catalytic asymmetric hydrogenation of pyridines for the synthesis of piperidines remains a challenge. Herein, we report a one-pot asymmetric hydrogenation of pyridines with subsequent N-alkylation using a traceless Brønsted acid activation strategy. Catalyzed by an iridium-BINAP complex, the substrates undergo ketone reduction, cyclization and pyridine hydrogenation in sequence to form indolizidines and quinolizidines. The absolute configuration of the stereocenter of the alcohol is retained and influences the formation of the second stereocenter. Experimental and theoretical mechanistic studies reveal that the chloride anion and certain noncovalent interactions govern the stereoselectivity of the cascade reaction throughout the catalytic process.