Asymmetric Synthesis of Triphenylmethanes via Organocatalytic Regio- and Enantioselective Friedel-Crafts Alkylation of Aniline Derivatives

Org Lett. 2023 Mar 17;25(10):1711-1716. doi: 10.1021/acs.orglett.3c00370. Epub 2023 Mar 9.

Abstract

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.