Department of Chemistry, Zhejiang University, Hangzhou, 310058, China.
Nat Commun. 2020 Feb 7;11(1):783. doi: 10.1038/s41467-020-14459-x.
Highly regio- and enantioselective intermolecular hydroamination of alkenes is a challenging process potentially leading to valuable chiral amines. Hydroamination of alkenes via metal-catalyzed hydrogen atom transfer (HAT) with good regioselectivity and functional group tolerance has been reported, however, high enantioselectivity has not been achieved due to the lack of suitable ligands. Here we report a ligand-promoted cobalt-catalyzed Markovnikov-type selective radical hydroamination of alkenes with diazo compounds. This operationally simple protocol uses unsymmetric NNN-tridentate (UNT) ligand, readily available alkenes and hydrosilanes to construct hydrazones with good functional group tolerance. The hydrazones can undergo nitrogen-nitrogen bond cleavage smoothly to deliver valuable amine derivatives. Additionally, asymmetric intermolecular hydroamination of unactivated aliphatic terminal alkenes using chiral N-imidazolinylphenyl 8-aminoquinoline (IPAQ) ligands has also been achieved to afford chiral amine derivatives with good enantioselectivities.
高区域和对映选择性的烯烃的分子间氨氢化是一个具有挑战性的过程，可能导致有价值的手性胺。通过金属催化的氢原子转移（HAT）进行烯烃的氨氢化具有良好的区域选择性和官能团耐受性，但由于缺乏合适的配体，因此没有实现高对映选择性。在这里，我们报告了一种配体促进的钴催化 Markovnikov 型选择性自由基烯烃与重氮化合物的氨氢化。该操作简单的方案使用不对称的 NNN-三齿（UNT）配体、易得的烯烃和硅烷氢来构建具有良好官能团耐受性的腙。腙可以顺利地进行氮-氮键断裂，从而得到有价值的胺衍生物。此外，使用手性 N-咪唑啉基苯基 8-氨基喹啉（IPAQ）配体还实现了未活化的脂肪族末端烯烃的不对称分子间氨氢化，以获得具有良好对映选择性的手性胺衍生物。
