Effect of the ancillary ligand in N-heterocyclic carbene iridium(III) catalyzed N-alkylation of amines with alcohols
作者:Xinshu Feng、Ming Huang
DOI:10.1016/j.poly.2021.115289
日期:2021.9
of air-stable N-heterocyclic carbene (NHC) Ir(III) complexes (Ir1-6), bearing various combinations of chlorine, pyridine and NHC ligands, were assayed for the N-alkylation of amines with alcohols. It was found that Ir3, with two monodentate 1,3-bis-methyl-imidazolylidene (IMe) ligands, emerged as the most active complex. A large variety of amines and primary alcohols were efficiently converted into
一系列空气稳定的ñ -杂环卡宾(NHC)的Ir(III)络合物(IR1 - 6),轴承氯,吡啶和NHC配体的各种组合,进行测定的Ñ与醇胺的烷基化。据发现,Ir3的,具有两个单齿1,3-双甲基imidazolylidene(IME)的配体,成为最活跃的复合物。多种胺和伯醇被有效地转化为单-N-烷基化胺,产率为 53-96%。作为一个特别的亮点,对于具有挑战性的 MeOH,选择性N-单甲基化可以在空气气氛下使用 KOH 作为碱来实现。此外,该催化体系已成功应用于一些有价值化合物的克级合成。