Binaphthyl-based chiral sulfonimide (CSI) is demonstrated for the first time to be an efficient, strong Brønsted acid in asymmetric organocatalysis. A series of CSIs were synthesized and screened in the asymmetric Friedel–Crafts alkylation of indoles with imines. Good to excellent yields and enantioselectivities have been achieved. It was proved that it was crucial to wash the CSI catalyst with HCl
首次证明了基于联
萘基的手性磺
酰亚胺(CSI)在不对称有机催化中是一种有效的强布朗斯台德酸。合成了一系列CSI,并在
亚胺与
吲哚的不对称Friedel-Crafts烷基化反应中进行了筛选。已经获得了良好至优异的产率和对映选择性。事实证明,在使用前用HCl清洗CSI催化剂至关重要。