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.
Hg(OTf)2-Catalyzed cyclization of alkynyl tert-butylcarbonate leading to cyclic enol carbonate
摘要:
Mercuric triflate was shown to be a powerful catalyst for the cyclization of alkynyl tert-butylcarbonates giving rise to cyclic enol carbonates under mild conditions. Internal alkynyl carbonate affords endo cyclization product selectively, while terminal alkynyl carbonate provides only exo cyclization product. (c) 2006 Elsevier Ltd. All rights reserved.
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
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。
Efficient chemical fixation of CO2 promoted by a bifunctional Ag2WO4/Ph3P system
作者:Qing-Wen Song、Bing Yu、Xue-Dong Li、Ran Ma、Zhen-Feng Diao、Rong-Guan Li、Wei Li、Liang-Nian He
DOI:10.1039/c3gc42406e
日期:——
anion is proposed. Recycling trials on carboxylative cyclization of propargyl alcohols and CO2 illustrate that the catalyst can be reused at least 4 times with retention of high catalytic activity and selectivity. Especially, it allows the direct and effective application in the one-pot synthesis of various oxazolidinones bearing exocyclic alkenes and carbamates in moderate to high yields upon the alternative
通过炔丙醇和CO 2的羧化组装,开发了一种高效的多相银催化的α-亚甲基环状碳酸酯基序的构建反应。在室温下,在无溶剂条件下,仅用1 mol%的Ag 2 WO 4和2 mol%的PPh 3以及大气中的CO 2平稳地进行这种CO 2固定方案,对环境无害且低能耗。简单的操作程序。值得注意的是,仅通过化学选择性就可以达到高达98%的分离的碳酸盐收率。另外,Ag 2 WO 4的双重活化能力面向炔丙基底物和CO 2的基础是,提出了银阳离子和钨酸根阴离子的协同催化机理。炔丙醇和CO 2的羧基环化的循环试验表明,该催化剂可重复使用至少4次,同时保留了高催化活性和选择性。特别地,它允许在交替引入伯胺或仲胺时以中等至高收率直接有效地将各种带有环外烯烃和氨基甲酸酯的恶唑烷酮单锅合成。
A highly stable polyoxovanadate-based Cu(<scp>i</scp>)–MOF for the carboxylative cyclization of CO<sub>2</sub>with propargylic alcohols at room temperature
作者:Hong-Rui Tian、Zhong Zhang、Shu-Mei Liu、Tian-Yi Dang、Zhuo Li、Ying Lu、Shu-Xia Liu
DOI:10.1039/d0gc02812f
日期:——
to stably exist in various solvents and pH = 2–12 solutions. Additionally, the V–Cu–MOF as a heterogeneous catalyst can catalyze the carboxylative cyclization of CO2 and propargylicalcohols to high value-added α-alkylidene cyclic carbonates at room temperature, and the conversion and selectivity are almost 100%. More importantly, no obvious decrease in the yield of the α-alkylidene cyclic carbonate
一种新型的基于聚氧钒酸盐的铜(I)-有机骨架,[Cu I(bib)] 4 V V 4 O 12 }(V-Cu-MOF,bib = 1,4-bis(1 H-咪唑基-1- ))在温和的水热条件下容易合成。V–Cu–MOF的结构由环状V 4 O 12 } 4-阴离子基团和一维链Cu(I)–MOF([Cu I(bib)] +)构成。V 4 O 12 } 4−团簇的存在稳定了Cu(I)–MOF和Cu(I)作为中心,从而提高了V–Cu–MOF的稳定性,使其能够稳定地存在于各种溶剂和pH = 2–12的溶液中。此外,V-Cu-MOF作为非均相催化剂可以在室温下催化CO 2和炔丙醇向高附加值α-亚烷基环状碳酸酯的羧化环化反应,转化率和选择性几乎达到100%。更重要的是,在十个循环后,没有观察到α-亚烷基环状碳酸酯的收率明显降低。这些结果表明V-Cu-MOF具有出色的催化活性和可持续性。对催化反应机理
Alkoxide-functionalized imidazolium betaines for CO<sub>2</sub> activation and catalytic transformation
作者:Yan-Bo Wang、Dong-Sheng Sun、Hui Zhou、Wen-Zhen Zhang、Xiao-Bing Lu
DOI:10.1039/c3gc42346h
日期:——
Alkoxide-functionalized imidazolium betaines (AFIBs) functioned as organocatalysts for the coupling of CO2 with propargylic alcohols to give valuable cyclic carbonates via AFIB-CO2 adducts.