Ni-Catalyzed dehydrogenative coupling of primary and secondary alcohols with methyl-N-heteroaromatics

Abstract

Here we report the first base-metal catalyzed dehydrogenative coupling of primary (aromatic, heteroaromatic, and aliphatic) and secondary alcohols with methyl-N-heteroaromatics to form various C(sp³)-alkylated N-heteroaromatics. The reaction is enabled by Earth abundant, non-precious NiBr₂ as a transition metal catalyst and N,N,N′,N′-tetramethylethylenediamine (TMEDA) as a ligand system. Mechanistic studies reveal that a hydrogen auto-transfer process is involved in the direct C(sp³)-alkylation and the reaction proceeds through an α-olefination process.