Song Qing-Wen, Chen Wei-Qiang, Ma Ran, Yu Ao, Li Qiu-Yue, Chang Yao, He Liang-Nian
State Key Laboratory and Institute of Elemento-Organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin, 300071 (PR China).
ChemSusChem. 2015 Mar;8(5):821-7. doi: 10.1002/cssc.201402921. Epub 2014 Dec 15.
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.
在大气压力和室温下将二氧化碳进行化学转化仍然是一个巨大的挑战。碳酸银（I）的三苯基膦配合物被证明是一种强大的双功能催化剂，可在环境条件下催化炔丙醇与二氧化碳的羧基环化反应，以优异的产率生成α-亚甲基环状碳酸酯。[（PPh3）2Ag]2CO3前所未有的性能可能归因于其对二氧化碳和炔丙醇的同时活化作用。此外，催化物种高度兼容的碱性使炔丙醇能够与二氧化碳反应生成关键的碳酸银烷基酯中间体：体积较大的[（Ph3P）2Ag（I）]+有效地活化碳-碳三键并增强烷基碳酸根阴离子的O-亲核性，从而极大地促进分子内亲核环化反应。值得注意的是，该催化方法对于炔丙醇、仲胺和二氧化碳（在大气压力下）反应生成β-氧代丙基氨基甲酸酯的反应也同样有效。
