Asymmetric Synthesis of Triphenylmethanes via Organocatalytic Regio- and Enantioselective Friedel-Crafts Alkylation of Aniline Derivatives.
Rui-Lin ZhangBo LiuKai-Xiong QiuHong-Tao LiHui-Nan ZhangBao-Chun ShenZhong-Wen SunPublished in: Organic letters (2023)
Herein, we described a highly regio- and enantioselective Friedel-Crafts alkylation of aniline derivatives with in situ generated ortho -quinone methides enabled by chiral phosphoric acid, furnishing a wide range of enantioenriched triarylmethanes bearing three similar benzene rings in high yields (up to 98%) with excellent stereoselectivities (up to 98% ee). Furthermore, the large-scale reactions and diversified transformations of product demonstrate the practicality of the protocol. Density functional theory calculations elucidate the origin of the enantioselectivity.