Mishra Manmath, De Pinaki Bhusan, Pradhan Sourav, Punniyamurthy Tharmalingam
Department of Chemistry , Indian Institute of Technology Guwahati , Guwahati 781039 , India.
J Org Chem. 2019 Sep 6;84(17):10901-10910. doi: 10.1021/acs.joc.9b01506. Epub 2019 Aug 14.
Aerobic copper(II)-catalyzed tandem ring opening and oxidative C-H alkylation of donor-acceptor cyclopropanes with bisaryl hydrazones is accomplished to produce tetrahydropyridazines, in which copper(II) plays dual role as a Lewis acid as well as redox catalyst. The reaction is stereospecific, and optically active cyclopropanes can be reacted with high optical purities (89-98% enantiomeric excess). The substrate scope, functional group tolerance, dual role of the copper(II) catalyst, and the use of air as an oxidant are the important practical features. A product bearing a 3-bromoaryl group can be subjected to Pd-catalyzed Suzuki coupling with boronic acid in high yield.
实现了有氧铜（II）催化的供体-受体环丙烷与双芳基腙的串联开环和氧化C-H烷基化反应，以生成四氢哒嗪，其中铜（II）作为路易斯酸和氧化还原催化剂发挥双重作用。该反应具有立体专一性，光学活性环丙烷可以以高光学纯度（对映体过量89-98%）进行反应。底物范围、官能团耐受性、铜（II）催化剂的双重作用以及使用空气作为氧化剂是重要的实际特点。带有3-溴芳基的产物可以高产率地进行钯催化的与硼酸的铃木偶联反应。
