A sensitive amine-responsive disassembly of self-assembled AuI -CuI double salts was observed and its utilization for the synergistic catalysis was enlightened. Investigation of the disassembly of [Au(NHC)2 ][CuI2 ] revealed the contribution of Cu-assisted ligand exchange of N-heterocyclic carbene (NHC) by amine in [Au(NHC)2 ]+ and the capacity of [CuI2 ]- on the oxidative step. By integrating the
Iron-catalyzed urea synthesis: dehydrogenative coupling of methanol and amines
作者:Elizabeth M. Lane、Nilay Hazari、Wesley H. Bernskoetter
DOI:10.1039/c8sc00775f
日期:——
byproduct. Mechanistic studies indicate a stepwise pathway beginning with methanol dehydrogenation to give formaldehyde, which is trapped by amine to afford a formamide. The formamide is then dehydrogenated to produce a transient isocyanate, which reacts with another equivalent of amine to form a urea. These mechanisticinsights enabled the development of an iron-catalyzed method for the synthesis of unsymmetric
取代脲有许多应用,但它们的合成通常需要使用剧毒的起始材料。在此,我们描述了第一种通过甲醇与伯胺脱氢偶联选择性合成对称脲的贱金属催化剂。使用钳形负载铁催化剂,生成了一系列尿素,分离产率高达 80%(相当于催化转化率高达 160),且 H 2为唯一副产物。机理研究表明,从甲醇脱氢开始逐步生成甲醛,甲醛被胺捕获,生成甲酰胺。然后甲酰胺脱氢产生暂时的异氰酸酯,其与另一当量的胺反应形成脲。这些机理见解使得铁催化方法得以开发,用于从酰胺和胺合成不对称脲。
Ruthenium-Catalyzed Urea Synthesis by N–H Activation of Amines
observed in situ, which resulted in the formation of CO and dimethylamine. The scope of this new mode of bond activation is extended to the synthesis of urea derivatives from amines using DMF as a carbon monoxide (CO) surrogate. This catalytic protocol allows the synthesis of simple and functionalized urea derivatives with liberation of hydrogen, devoid of any stoichiometric activating reagents, and avoids
Polynuclear Gold [Au<sup>I</sup>
]<sub>4</sub>
, [Au<sup>I</sup>
]<sub>8</sub>
, and Bimetallic [Au<sup>I</sup>
<sub>4</sub>
Ag<sup>I</sup>
] Complexes: C−H Functionalization of Carbonyl Compounds and Homogeneous Carbonylation of Amines
作者:Ekaterina S. Smirnova、José M. Muñoz Molina、Alice Johnson、Nuno A. G. Bandeira、Carles Bo、Antonio M. Echavarren
DOI:10.1002/anie.201603200
日期:2016.6.20
tetranuclear gold complexes, a structurally unprecedented octanuclear complex with a planar [Au(I) 8 ] core, and pentanuclear [Au(I) 4 M(I) ] (M=Cu, Ag) complexes is presented. The linear [Au(I) 4 ] complex undergoes C-H functionalization of carbonyl compounds under mild reaction conditions. In addition, [Au(I) 4 Ag(I) ] catalyzes the carbonylation of primary amines to form ureas under homogeneous conditions
作者:Phillip A. Shelton、Yue Zhang、Thi Hoang Ha Nguyen、Lisa McElwee-White
DOI:10.1039/b819891h
日期:——
Oxidative carbonylation of amines using NaIO4 as the oxidant and NaI as a promoter affords good to excellent yields of ureas from primary amines in the absence of transition metalcatalysts.
使用 NaIO4 作为氧化剂和 NaI 作为促进剂的胺的氧化碳基化反应,可以在没有过渡金属催化剂的情况下,从初级胺中获得良好到优异的尿素产率。