a first copper‐catalyzed synthesis of α‐aryl‐β‐borylstannane compounds was accomplished through three‐component borylstannation of aryl‐substituted alkenes. In the exploration of an asymmetric variant, chiral sulfinylphosphine ligands proved advantageous in controlling stereochemistry of BCu addition and in promoting transmetalation of enantioenriched alkylCu species. The stereochemical outcome