83444-26-2Relevant articles and documents
Nickel Complexes Bearing N,N,O-Tridentate Salicylaldiminato Ligand: Efficient Catalysts for Imines Formation via Dehydrogenative Coupling of Primary Alcohols with Amines
Han, Zhangang,Hao, Zhiqiang,Lin, Jin,Lu, Guo-Liang,Zhang, Junhua,Zhang, Xiaoying
, p. 3843 - 3853 (2021/11/18)
Treatment of salicylaldiminato ligand L1H-L2H (L1H = 2,4-di-tert-butyl-6-((quinolin-8-ylimino)methyl)phenol; L2H = 2,4-di-tert-butyl-6-(((2-(diethylamino)ethyl)imino)methyl)phenol) with Ni(OAc)2·4H2O in refluxing ethanol afforded nickel complexes [(L1)Ni(OAc)] (1) and [(L2)Ni(OAc)] (2), respectively. Reaction of L3H (L3H = (2,4-di-tert-butyl-6-(((2-(pyridin-2-yl)ethyl)imino)methyl)phenol)) with Ni(OAc)2·4H2O in the presence of excess triethylanmine gave the dual ligands coordinated nickel complex [(L2)2Ni] (3). Complexes 1-3 were well characterized by high-resolution mass spectrometry, infrared spectroscopy, elemental analysis, and X-ray diffraction analysis. All the three Ni(II) complexes exhibited efficient activity and good selectivity in the acceptorless dehydrogenative coupling of alcohols and amines to produce imines and diimines. The present protocol provides an atom-economical and sustainable route for the synthesis of various imine derivatives by employing an earth-abundant nickel salt and easily prepared salicylaldiminato ligands.
Nickel(II)-NΛNΛO Pincer Type Complex-Catalyzed N-alkylation of Amines with Alcohols via the Hydrogen Autotransfer Reaction
Balamurugan, Gunasekaran,Ramesh, Rengan,Malecki, Jan Grzegorz
, p. 7125 - 7135 (2020/06/08)
A highly sustainable catalytic protocol for the coupling of alcohols and amines for selective monoalkylated amines using Ni(II)-NΛNΛO pincer type complexes through the borrowing hydrogen methodology is described. An array of Ni(II) catalysts (1-3) was synthesized and characterized by various spectral and analytical methods. Furthermore, the distorted square planar geometry of the complexes (1 and 2) was substantiated with single crystal X-ray diffraction study. The inexpensive nickel-based catalytic methodology displays a broad substrate scope for the N-alkylation of aromatic and heteroaromatic amines using a diverse range of primary alcohols with excellent yields up to 97%. The present approach is environmentally benign, which liberates water as the sole byproduct. A short synthesis of drug intermediates such as mepyramine and chloropyramine illustrates the utility of the present protocol.
Manganese catalyzed reductive amination of aldehydes using hydrogen as a reductant
Wei, Duo,Bruneau-Voisine, Antoine,Valyaev, Dmitry A.,Lugan, No?l,Sortais, Jean-Baptiste
supporting information, p. 4302 - 4305 (2018/05/03)
A one-pot two-step procedure was developed for the alkylation of amines via reductive amination of aldehydes using molecular dihydrogen as a reductant in the presence of a manganese pyridinyl-phosphine complex as a pre-catalyst. After the initial condensation step, the reduction of imines formed in situ is performed under mild conditions (50-100 °C) with 2 mol% of catalyst and 5 mol% of tBuOK under 50 bar of hydrogen. Excellent yields (>90%) were obtained for a large combination of aldehydes and amines (40 examples), including aliphatic aldehydes and amino-alcohols.
