Nickel‐Catalyzed Chemodivergent Coupling of Alcohols: Efficient Routes to Access α,α‐Disubstituted Ketones and α‐Substituted Chalcones

Abstract

AbstractChemodivergent (de)hydrogenative coupling of primary and secondary alcohols is achieved utilizing an inexpensive nickel catalyst, (6‐OH‐bpy)NiCl2. This protocol demonstrates the synthesis of branched carbonyl compounds, α,α‐disubstituted ketones, and α‐substituted chalcones via borrowing hydrogen strategy and acceptorless dehydrogenative coupling, respectively. A wide range of aryl‐based secondary alcohols are coupled with various primary alcohols in this tandem dehydrogenation/hydrogenation reaction. The nickel catalyst, along with KOtBu or K2CO3, governed the selectivity for the formation of branched saturated ketones or chalcones. A preliminary mechanistic investigation confirms the reversible dehydrogenation of alcohols to carbonyls via metal‐ligand cooperation (MLC) and the involvement of radical intermediates during the reaction.