Reductive amination of various ketones and aldehydes by transferhydrogenation under aqueous conditions has been developed, by using cyclometallated iridium complexes as catalysts and formate as hydrogen source. The pH value of the solution is shown to be critical for a high catalytic chemoselectivity and activity, with the best pH value being 4.8. In comparison with that in organic solvents, the reductive
The present invention relates to an iridium-based catalyst compound for hydrogenating reducible moieties, especially imines and iminiums, the catalyst compounds being defined by the formula: (Formula (I)) where ring B is a conjugated ring system with one or more substituents. The catalysts of the invention are particularly effective in reductive amination procedures which involve the in situ generation of the imine or iminium under reductive hydrogenative conditions.
Half-Sandwich Ru(II) Complexes with N,O-Chelate Ligands: Diverse Catalytic Activity for Amine Synthesis in Water
作者:Xue-Jing Yun、Chun Ling、Wei Deng、Zhen-Jiang Liu、Zi-Jian Yao
DOI:10.1021/acs.organomet.0c00554
日期:2020.11.9
Several types of β-ketoamino based N,O-coordinate half-sandwich ruthenium complexes have been synthesized in moderate to good yields. The stable ruthenium complexes displayed good and diverse catalytic efficiency in reductiveamination between aldehydes and amines in aqueous solution. The method gave a facile route for one-pot synthesis of diverse complicated amines with a low catalyst loading by using
已经以中等至良好的产率合成了几种类型的基于β-酮氨基的N,O-配位半三明治钌络合物。稳定的钌络合物在水溶液中的醛和胺之间的还原胺化反应中表现出良好的催化效率。该方法通过使用廉价且毒性较小的HCOOH或干净的H 2作为氢源,为一锅法合成具有低催化剂负载量的多种复杂胺提供了一条简便的途径。催化剂Ru1表现出190 h –1的最高催化活性苯甲醛与苯胺的还原胺化反应中的TOF值。在标准催化体系下,相应的胺产物以优异的产率提供。有效和多样化的催化活性,广泛的物质范围,温和的条件以及对环境无害的溶剂使该系统潜在地可用于工业生产。使用NMR,元素分析和IR技术对钌配合物进行表征,以确认其结构。
Hydrogen-Borrowing Amination of Secondary Alcohols Promoted by a (Cyclopentadienone)iron Complex
作者:Xishan Bai、Francesco Aiolfi、Mattia Cettolin、Umberto Piarulli、Alberto Dal Corso、Luca Pignataro、Cesare Gennari
DOI:10.1055/s-0039-1690101
日期:2019.9
(HB) amination has been expanded to secondaryalcohols, which had previously been reported to react only in the presence of large amounts of co-catalysts. A range of cyclic and acyclic secondaryalcohols were reacted with aromatic and aliphatic amines giving fair to excellent yields of the substitution products. The catalyst was also able to promote the cyclization of diols bearing a secondary alcohol
Cyclometalated Half-Sandwich Iridium Complex for Catalytic Hydrogenation of Imines and Quinolines
作者:Zi-Jian Yao、Nan Lin、Xin-Chao Qiao、Jing-Wei Zhu、Wei Deng
DOI:10.1021/acs.organomet.8b00553
日期:2018.11.12
iridium-based catalysts for imines and quinoline derivatives reduction have been prepared through metal-mediated C–H bond activation based on benzothiazole ligands. These iridium complexes exhibited high catalytic activity for hydrogenation of various types of imines with high yields. The most active catalyst was obtained from methoxyl substituted complex 2, showing the catalytic TOF value of 975 h–1 for
通过基于苯并噻唑配体的金属介导的CH键活化,已经制备了几种用于亚胺和喹啉衍生物还原的C,N-螯合环金属化半三明治铱基催化剂。这些铱配合物对各种类型的亚胺的氢化显示出高催化活性。活性最高的催化剂是从甲氧基取代的配合物2获得的,对于还原亚胺6a的催化TOF值为975 h –1。另外,这些半三明治配合物还显示出对N-杂环喹啉衍生物的催化加氢的高效率。对于具有给电子或吸电子基团的各种底物显示出良好的催化活性。配合物1 - 5被完全表征通过NMR,IR和元素分析。通过X射线衍射分析进一步证实了配合物1和4的分子结构。