Catalytic Hydrogenation of Amides to Amines under Mild Conditions
作者:Mario Stein、Bernhard Breit
DOI:10.1002/anie.201207803
日期:2013.2.18
Under (not so much) pressure: A general method for the hydrogenation of tertiary and secondary amides to amines with excellent selectivity using a bimetallic Pd–Re catalyst has been developed. The reaction proceeds under low pressure and comparatively low temperature. This method provides organic chemists with a simple and reliable tool for the synthesis of amines.
Iron-Catalyzed Amide Formation from the Dehydrogenative Coupling of Alcohols and Secondary Amines
作者:Elizabeth M. Lane、Katherine B. Uttley、Nilay Hazari、Wesley Bernskoetter
DOI:10.1021/acs.organomet.7b00258
日期:2017.5.22
substituents on the amine or alcohol substrate. Variable-temperature NMR spectroscopic studies suggest that the catalyst resting state is an off-cycle iron(II) methoxide species, (iPrPN(H)P)Fe(H)(OCH3)(CO), resulting from addition of methanol across the Fe–N bond of (iPrPNP)Fe(H)(CO). This reversibly formed iron(II) methoxide complex is favored at mild temperatures but eliminates methanol upon heating
五配位氢化铁(II)络合物(i Pr PNP)Fe(H)(CO)(i Pr PNP = N [CH 2 CH 2(P i Pr 2)] 2)选择性催化醇和仲胺的脱氢分子间偶联以形成叔酰胺。这是迄今为止报道的最高效的脱氢酰胺化贱金属催化剂,在某些情况下可实现高达600的营业额。该催化剂对空间上不需要的胺和醇或环状底物效果很好,并且在从甲醇合成甲酰胺中特别有效。然而,随着胺或醇底物上大取代基的引入,催化剂性能迅速下降。变温NMR光谱研究表明,催化剂静止状态是关断周期铁(II)甲醇物种,(我镨PN(H)P)的Fe(H)(OCH 3)(CO),是由于在(i Pr PNP)Fe(H)(CO)的Fe–N键上添加了甲醇。这种可逆形成的甲醇铁(II)配合物在温和的温度下很受青睐,但加热时会消除甲醇。
Transamidation of amides with amines under solvent-free conditions using a CeO2 catalyst
with n-octylamine. CeO2 acts as a reusable and effective heterogeneous catalyst for transamidation undersolvent-freeconditions. Transamidation of a variety of amides and amines produced the corresponding N-alkyl amides in high yields. This method provides the first example of a heterogeneous catalyst for transamidation using aliphatic amines as substrates. Characterization of acid–base properties
thermally activated IrCl(PPh3)3 (8). Both catalysts showed excellent activity toward the selective conversion of a variety of N,N-dialkyl-, N-alkyl-N-aryl-, and N,N-diarylamides to the corresponding enamines with low catalyst loadings. The 14-electron species “ClIr(PPh3)2”, which is stabilized by solvents or reactants in the actual catalytic reactions, could be involved in the catalysis, which produces
Recyclable Hypervalent Iodine(III) Reagent Iodosodilactone as an Efficient Coupling Reagent for Direct Esterification, Amidation, and Peptide Coupling
作者:Jun Tian、Wen-Chao Gao、Dong-Mei Zhou、Chi Zhang
DOI:10.1021/ol301085v
日期:2012.6.15
hypervalent iodine(III) reagent plays a novel role as an efficient coupling reagent to promote the direct condensation between carboxylicacids and alcohols or amines to provide esters, macrocyclic lactones, amides, as well as peptides without racemization. The regeneration of iodosodilactone (1) can also be readily achieved. The intermediate acyloxyphosphonium ion C from the activation of a carboxylic acid