Shenzhen Grubbs Institute and Department of Chemistry, Guangdong Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen 518055, China.
Org Lett. 2020 Sep 18;22(18):7278-7283. doi: 10.1021/acs.orglett.0c02614. Epub 2020 Sep 8.
The borrowing-hydrogen (or hydrogen autotransfer) process, where the catalyst dehydrogenates a substrate and formally transfers the H atom to an unsaturated intermediate, is an atom-efficient and environmentally benign transformation. Described here is an example of an asymmetric borrowing-hydrogen cascade for the formal anti-Markovnikov hydroamination of allyl alcohols to synthesize optically enriched γ-secondary amino alcohols. By exploiting the Ru-()-PrPyme catalyst with minimal stereogenicity, a cascade process including dehydrogenation, conjugate addition, and asymmetric reduction was developed. The mild conditions, functional group tolerance, and broad substrate scope (54 examples) demonstrate the synthetic practicality of the catalytic system.
borrowing-hydrogen（或氢自动转移）过程中，催化剂使底物脱氢，并将 H 原子正式转移到不饱和中间体上，这是一种原子经济且环境友好的转化。这里描述的是不对称 borrowing-hydrogen 级联反应的一个例子，用于烯丙醇的形式反 Markovnikov 氢胺化反应，以合成光学富集的γ-仲氨基醇。通过利用具有最小手性的 Ru-()-PrPyme 催化剂，开发了包括脱氢、共轭加成和不对称还原在内的级联反应。温和的条件、官能团耐受性和广泛的底物范围（54 个实例）证明了催化体系的合成实用性。
