products and byproducts. Coating of γ-Al2O3 with silicotungstic acid or its semisalt can significantly enhance its catalytic activity in amine oxidation. The adsorption of amine on weak acidic sites of catalyst is essential for its oxidation to main reaction products. Cycloalkylamines are oxidized mainly to cyclic oximes (selectivity up to 64%) and Schiff bases of appropriate cycloalkanone and cycloalkylamine
Transition Metal-Free Oxidative Coupling of Primary Amines in Polyethylene Glycol at Room Temperature: Synthesis of Imines, Azobenzenes, Benzothiazoles, and Disulfides
作者:Abhinandan D. Hudwekar、Praveen K. Verma、Jaspreet Kour、Shilpi Balgotra、Sanghapal D. Sawant
DOI:10.1002/ejoc.201801610
日期:2019.2.14
A transition metal‐free protocol has been developed for the oxidativecoupling of primary amines to imines and azobenzenes, thiols to disulfides, and 2‐aminothiophenols to benzothiazoles, offering excellent yields. The advantageous features of the present environmentally benign methodology include the usage of biocompatable and green reaction conditions such as solvent, room temperature reactions,
Cultivation of a Cu/HMPC catalyst from a hyperaccumulating mustard plant for highly efficient and selective coupling reactions under mild conditions
作者:Mayakrishnan Gopiraman、Kai Wei、Ke-Qin Zhang、Ill-Min Chung、Ick Soo Kim
DOI:10.1039/c7ra12470h
日期:——
determined to be 620.8 m2 g−1. The Cu/HMPC actively transformed a wide range of amines to imines under very mildreactionconditions. The catalyst Cu/HMPC gave products in excellent yields (98–61%) with very high TON/TOF values (1512/339–833/35 h−1). To the best of our knowledge, this is the most efficient Cu-based heterogeneous eco-catalyst for the synthesis of imines among those reported to date. The
含铜活性炭(生态催化剂,Cu/HMPC,其中“C”定义“碳”)是通过简单的化学活化方法从金属超富集芥菜植物 (HMP) 中提取的。透射电子显微镜/选区衍射 (HRTEM/SAED) 结果表明,Cu/HMPC 主要具有三种形态[片状形态 (2D)、空心球 (3D) 和针状结构 (1D)]是相互联系的。HRTEM-SAED、拉曼和 X 射线光电子能谱 (XPS) 结果证实了 Cu/HMPC 中存在 Cu 氧化物物种。Cu/HMPC中的Cu含量测定为1.03 wt%。使用拉曼和 XRD 结果讨论了 Cu/HMPC 中石墨化的质量。Cu/HMPC的BET表面积确定为620.8 m 2 g -1. 在非常温和的反应条件下,Cu/HMPC 可将多种胺类主动转化为亚胺类。催化剂 Cu/HMPC 以非常高的 TON/TOF 值 (1512/339–833/35 h -1 )以优异的产率 (98–61%)
Switchable activity of a Ru catalyst bearing an annulated mesoionic carbene ligand for oxidation of primary amines
作者:Suman Yadav、Saikat Pal、Nilay Kumar Pal、Noor U Din Reshi、Sourav Pal、Jitendra K. Bera
DOI:10.1002/aoc.6594
日期:——
mesoionic carbene (MIC) ligand, is examined for the oxidation of primaryamines. Complex 1 affords nitrile or imine depending on the nature of the terminal oxidants and solvents used in the reactions. Primaryamines are converted to nitriles using NaIO4 in EtOAc/H2O mixture, whereas imines are obtained under O2 balloon pressure in toluene. A variety of nitriles and imines are accessed with high yields and
带有稠合π-共轭咪唑并[1,2- a ][1,8]萘啶基介离子卡宾(MIC)配体的Ru配合物1的催化活性被检测为伯胺的氧化。配合物1提供腈或亚胺,具体取决于反应中使用的末端氧化剂和溶剂的性质。使用NaIO 4在EtOAc/H 2 O混合物中将伯胺转化为腈,而亚胺则在O 2气球压力下在甲苯中获得。以高产率和选择性获得多种腈和亚胺。进行了一系列控制实验、反应曲线和动力学研究,以揭示腈和亚胺形成的机制细节。催化反应说明了伯胺氧化过程中对氧化剂和溶剂选择的微妙依赖性。