Highly Enantioselective Construction of Trifluoromethylated All-Carbon Quaternary Stereocenters via Nickel-Catalyzed Friedel–Crafts Alkylation Reaction
作者:Jian-Rong Gao、Hao Wu、Bin Xiang、Wu-Bin Yu、Liang Han、Yi-Xia Jia
DOI:10.1021/ja400650m
日期:2013.2.27
A highly enantioselective Friedel-Crafts alkylation reaction of indoles with β-CF(3)-β-disubstituted nitroalkenes was achieved using a Ni(ClO(4))(2)-bisoxazoline complex as a catalyst, which afforded indole-bearing chiral compounds with trifluoromethylated all-carbon quaternary stereocenters in good yields with excellent enantioselectivities (up to 97% ee). The transformation of one of the products
使用Ni(ClO(4))(2)-双恶唑啉配合物作为催化剂,实现了吲哚与β-CF(3)-β-二取代硝基烯烃的高度对映选择性Friedel-Crafts烷基化反应,得到了含吲哚的手性化合物具有三氟甲基化的全碳四元立体中心,收率良好,对映选择性出色(高达 97% ee)。通过连续硝基还原和 Pictet-Spengler 环化反应,其中一个产物首先转化为三氟甲基化色胺,然后转化为三氟甲基化四氢-β-咔啉,同时完全保留了对映体纯度。