Manganese-Catalyzed β‑Alkylation of Secondary Alcohols with Primary Alcohols under Phosphine-Free Conditions

Manganese(I)
complexes bearing a pyridyl-supported pyrazolyl-imidazolyl
ligand efficiently catalyzed the direct β-alkylation of secondary
alcohols with primary alcohols under phosphine-free conditions. The
β-alkylated secondary alcohols were obtained in moderate to
good yields with water formed as the byproduct through a borrowing
hydrogen pathway. β-Alkylation of cholesterols was also effectively
achieved. The present protocol provides a concise atom-economical
method for C–C bond formation from primary and secondary alcohols.

负载有吡啶支撑型吡唑基咪唑基配体的一价锰配合物，可在无膦条件下高效催化伯醇与仲醇的直接β-烷基化反应。目标β-烷基化仲醇产物可获得中等至良好的产率，反应经由借氢路径进行，副产物仅为水。胆固醇的β-烷基化反应同样可高效实现。本方法为利用伯醇与仲醇构建C-C键提供了一种简洁的原子经济性路径。