Borane-Catalyzed Enantioselective\nα‑Alkylation\nof Unactivated 2‑Alkylbenzoxazoles with Electron-Deficient\nOlefins

Chiral borane–catalyzed reactions have recently\nemerged\nas a powerful tool for the enantioselective production of chiral scaffolds.\nIn this study, we demonstrated for the first time that a chiral bisborane\ncatalyst can be used for the α-functionalization of 2-alkylazaarenes;\nspecifically, we accomplished unprecedented highly enantioselective\nα-alkylation of unactivated 2-alkylbenzoxazoles with electron-deficient\nolefins. The strong Lewis acidity and the steric bulk of the bisborane\ncatalyst were essential to the observed reactivity and selectivity.