Pd-Catalyzed Regioselective Arylation of <i>gem</i> -Difluoroallenes: Access to Tertiary and Quaternary Center-Tethered Difluoroalkenes

Herein, we report a Pd-catalyzed γ- selective protoarylation of gem -difluoroallenes with arylboronic acids to rapidly access gem -difluoroalkenes bearing sterically congested tertiary and quaternary carbon centers. The transformation proceeds under mild, base-free conditions, using water as a key additive, and features short reaction times. The protocol delivers products with retention of the difluoro motif and exhibits a broad substrate scope with good to excellent yields. The method further enables deuterium incorporation from D 2 O and representative downstream transformations. Mechanistic studies reveal the crucial roles of the gem -difluoro group and water, while preliminary asymmetric results demonstrate the feasibility of enantioinduction.