Asymmetric <i>para</i> -Functionalization of Anilines Via Chiral Phosphoric Acid Catalysis: Access to CF ₃ -Substituted Indole–Aniline Quaternary Stereocenters

We report a chiral phosphoric acid-mediated <i>para</i>-selective functionalization of diphenylamines with propargylic 3-methyleneindoles, enabling the construction of acyclic quaternary stereocenters bearing a trifluoromethyl substituent under mild conditions. This protocol delivers indole-aniline frameworks in good yields and excellent enantioselectivities (up to 99% ee) across 26 examples with a broad tolerance to indole, alkyne, and aniline substitution. Late-stage modification of estrone and l-menthol derivatives and diversification to urea and triazole scaffolds underscore utility, expanding asymmetric <i>para</i>-functionalization of anilines.