Nickel-Catalyzed Deoxyvinylation of Benzyl Alcohols via Cross-Electrophile Coupling with Vinyl Bromides

Transition-metal-catalyzed cross-coupling directly utilizing alcohols remains a formidable challenge. Herein, we report a synergistic strategy integrating in situ chlorination with reductive coupling to achieve the efficient synthesis of allylbenzenes from benzyl alcohols and vinyl bromides. The 2-chloro-3-ethylbenzo[d]oxazol-3-ium salt (CEBO)/TBACl system serves as a mild chlorinating agent, enabling the conversion of benzyl alcohols to benzyl chlorides in THF in less than 1 min. This activation step exhibits exquisite chemoselectivity and allows for the kinetic, quantitative transformation of polyols. Seamlessly interfacing with a nickel catalytic cycle, this protocol eliminates the need for prefunctionalized benzyl halides and demonstrates broad functional group tolerance. By enabling the precise and quantitative modification of polyols, this work streamlined the direct vinylation of hydroxyl-containing compounds. Notably, this methodology breaks new ground by accommodating both conjugated and nonconjugated vinyl halides, thereby facilitating the development of a broader repertoire of efficient derivatizations.