Bifunctional silver(I) complex-catalyzed CO2 conversion at ambient conditions: synthesis of α-methylene cyclic carbonates and derivatives.
Bifunctional silver(I) complex-catalyzed CO2 conversion at ambient conditions: synthesis of α-methylene cyclic carbonates and derivatives.
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DOI：
10.1002/cssc.201402921
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发表时间：
2015-03
期刊：
影响因子：
8.4
通讯作者：
Qing-Wen Song;Wei-qiang Chen;Ran Ma;A. Yu;Qiu‐Yue Li;Yao Chang;Liang‐Nian He
中科院分区：
文献类型：
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作者：
Qing-Wen Song;Wei-qiang Chen;Ran Ma;A. Yu;Qiu‐Yue Li;Yao Chang;Liang‐Nian He
在常压和室温下CO2的化学转化仍然是一个巨大的挑战。三苯基膦配合物银碳酸盐是一种稳定的双功能催化剂，可用于炔丙醇和CO2在室温下的羧化环化反应，以高产率生成α-亚甲基环状碳酸酯。[（PPh 3）2Ag] 2CO 3的空前性能可能归因于CO2和炔丙醇的同时活化。此外，催化物种的高度相容的碱性允许炔丙醇与CO2反应，导致关键的银烷基碳酸酯中间体：较大的[（Ph 3 P）2Ag（I）]（+）有效地活化碳-碳三键并增强烷基碳酸阴离子的O-亲核性，从而极大地促进分子内亲核环化。值得注意的是，该催化方案对于炔丙醇、仲胺和CO2（在大气压下）的反应也很有效，得到β-氧代丙基氨基甲酸酯。
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 propargylic alcohols and CO2 at ambient conditions leading to the formation of α-methylene cyclic carbonates in excellent yields. The unprecedented performance of [(PPh3)2Ag]2CO3 is presumably attributed to the simultaneous activation of CO2 and propargylic alcohol. Moreover, the highly compatible basicity of the catalytic species allows propargylic alcohol to react with CO2 leading to key silver alkylcarbonate intermediates: the bulkier [(Ph3P)2Ag(I)](+) effectively activates the carbon-carbon triple bond and enhances O-nucleophilicity of the alkylcarbonic anion, thereby greatly promoting the intramolecular nucleophilic cyclization. Notably, this catalytic protocol also worked well for the reaction of propargylic alcohols, secondary amines, and CO2 (at atmospheric pressure) to afford β-oxopropylcarbamates.