Chiral N ‐Arylsulfonyl‐ N' ‐perfluoroalkylphospho‐ramidimidate Catalysts Enable Asymmetric Friedel–Crafts Alkylation of Arenes via Cyclopropylcarbinyl Cations

Comprehensive Summary The high reactivity and transient nature of non‐stabilized sp 3 ‐hybridized carbocations have long limited their application in enantiocontrolled transformations. Here, we report a catalytic strategy that addresses these challenges by harnessing cyclopropylcarbinyl cations as reactive yet controllable intermediates. Despite their rarity in asymmetric catalysis, these electrophiles enable highly enantioselective Friedel–Crafts alkylations when paired with newly developed chiral APPAIs catalysts. This method delivers excellent enantioselectivity and yields across a broad range of arenes. Unlike conventional methods requiring substrate preactivation, our approach directly utilizes alcohols, forming water as the only byproduct via an S N 1‐type pathway. This strategy expands the electrophile scope in asymmetric synthesis and offers new opportunities in chiral Brønsted acid catalysis and enantiocontrolled carbocation chemistry.