Preparation of Optically Active Cyclic Carbonates and 1,2-Diols via Enantioselective Hydrogenation of α-Methylenedioxolanones Catalyzed by Chiral Ruthenium(II) Complexes
摘要:
The enantioselective hydrogenation of alpha-methylene-1,3-dioxolan-2-ones catalyzed by chiral (diphosphine)ruthenium complexes leads to optically active cyclic carbonates with high enantioselectivities. Their hydrolysis in methanol in the presence of potassium carbonate quantitatively affords optically active 1,2-diols.
corresponding carbamic acid intermediates. The present bifunctionality could be applied to chemicalfixation of CO2 even at atmosphericpressure with various kinds of structurally diverse aryl diamines, primary monoamines, propargylic alcohols, and propargylic amines into cyclic urea derivatives, 1,3-disubstituted urea derivatives, cyclic carbonates, and cyclic carbamates, respectively.
Copper-catalysed synthesis of α-alkylidene cyclic carbonates from propargylic alcohols and CO<sub>2</sub>
作者:Alejandro Cervantes-Reyes、Kaveh Farshadfar、Matthias Rudolph、Frank Rominger、Thomas Schaub、Alireza Ariafard、A. Stephen K. Hashmi
DOI:10.1039/d0gc03990j
日期:——
propargylic alcohols and carbondioxide at room temperature. By using the combination of a sterically demanding BPDPrCuCl complex (BPDPr = 1,3-bis(2,6-diisopropylphenyl)-1,3-diazonine-2-ylidene) and CsF, as catalytic system, primary propargylic alcohols are efficiently converted to the corresponding α-alkylidenecycliccarbonates. Gram scale (up to 89% yield) and reusability experiments (74% global
Robust Silver(I) Catalyst for the Carboxylative Cyclization of Propargylic Alcohols with Carbon Dioxide under Ambient Conditions
作者:Qing-Wen Song、Liang-Nian He
DOI:10.1002/adsc.201500639
日期:2016.4.14
date for this conversion, with a very high turnover number of up to 6024, probably due to the synergistic effect of Lewis basic and Lewis acidic species for the activation of both propargylic alcohol and carbon dioxide by the formation of the alkyl carbonate with a bulkier counterion. Notably, this catalyst also worked well for the carboxylative cyclization of propargylic amines with carbon dioxide with
Effective Guanidine-Catalyzed Synthesis of Carbonate and Carbamate Derivatives from Propargyl Alcohols in Supercritical Carbon Dioxide
作者:Nicola Della Ca'、Bartolo Gabriele、Giuseppe Ruffolo、Lucia Veltri、Tito Zanetta、Mirco Costa
DOI:10.1002/adsc.201000607
日期:2011.1.10
The reactions of propargyl alcohols with carbondioxide in supercriticalcarbondioxide or in acetonitrile with gaseous carbondioxide in the presence of organic bases as catalysts have been examined. Bicyclic guanidines are effective catalysts for the formation of α‐methylene cyclic carbonates under mild reaction conditions. Oxoalkyl carbonates, oxoalkyl carbamates or α‐methyleneoxazolidinones are
Bifunctional Silver(I) Complex-Catalyzed CO<sub>2</sub>Conversion at Ambient Conditions: Synthesis of α-Methylene Cyclic Carbonates and Derivatives
作者:Qing-Wen Song、Wei-Qiang Chen、Ran Ma、Ao Yu、Qiu-Yue Li、Yao Chang、Liang-Nian He
DOI:10.1002/cssc.201402921
日期:2015.3
The chemical conversion of CO2 at atmospheric pressure and room temperature remains a great challenge. The triphenylphosphine complex of silver(I) carbonate was proved to be a robust bifunctional catalyst for the carboxylative cyclization of propargylicalcohols and CO2 at ambient conditions leading to the formation of α‐methylene cyclic carbonates in excellent yields. The unprecedented performance
在大气压和室温下,CO 2的化学转化仍然是一个巨大的挑战。事实证明,碳酸银(I)的三苯基膦配合物是一种强大的双功能催化剂,可在环境条件下对炔丙醇和CO 2进行羧化环化反应,从而以极好的收率形成α-亚甲基环状碳酸酯。[(PPh 3)2 Ag] 2 CO 3的空前性能可能归因于CO 2和炔丙醇的同时活化。此外,催化物种的高度相容的碱性使炔丙醇与CO 2反应导致形成关键的烷基碳酸银中间体:较大的[(Ph 3 P)2 Ag I ] +有效激活碳-碳三键并增强烷基碳阴离子的O-亲核性,从而大大促进了分子内亲核环化。值得注意的是,该催化方案也适用于炔丙醇,仲胺和CO 2(在大气压下)反应以生成β-氧代丙基氨基甲酸酯。