Borrowing hydrogen and dehydrogenative/oxidative cyclization reactions catalyzed by a CCC-NHC pincer Re complex: An air stable catalyst for the synthesis of α-alkylated ketones and quinolines
作者:Hoang H. Pham、T. Keith Hollis
DOI:10.1016/j.tetlet.2023.154569
日期:2023.6
CCC-NHC pincer Re(I) complex was achieved for the borrowing hydrogen coupling reaction between primary and secondary benzylic alcohols. An expansive scope of 17 aromatic and 2 aliphatic substrates were investigated and isolated yields from 40% to 91% were collected. The aliphatic substrates yielded complex aldol self-condensation by-products. The catalytic activity of the CCC-NHC pincer Re(I) complex was
CCC-NHC 钳状 Re(I) 配合物成功地催化了伯苄醇和仲苄醇之间的借氢偶联反应。研究了 17 种芳香族底物和 2 种脂肪族底物的广泛范围,并收集了 40% 至 91% 的分离产率。脂肪族底物产生复杂的羟醛自缩合副产物。CCC-NHC 夹钳 Re(I) 复合物的催化活性还通过 2-氨基苄醇与苄酮或仲苄醇的脱氢/氧化环化反应形成喹啉。12 个实例的分离产率为 68% 至 87%。所有产品和副产品均通过1 H & 13充分表征C NMR 和质谱。进行了脱氢和氢转移反应等控制研究,这些实验的结果支持了由 CCC-NHC 螯合 Re(I) 络合物催化的借氢偶联反应的拟议机制。