摘要
研究了2,2'-联吡啶钌配合物RuCl3(2,2'-bipy)(CH3OH)与十六烷基三甲基氯化铵(CTAC)组成的催化体系催化二氧化碳与不同的环氧化合物进行环加成反应制备环状碳酸酯.在此基础上,利用电喷雾质谱(ESI-MS)对RuCl3(2,2'-bipy)(CH3OH)/CTAC催化CO2与环氧丙烷(PO)反应制备碳酸丙烯酯(PC)进行了研究,检测到了反应中间态配合物RuCl3(2,2'-bipy)(PO)与RuCl3(2,2'-bipy)(PC),为该反应机理研究提供了实验证据.研究结果表明,RuCl3(2,2'-bipy)(CH3OH)/CTAC催化体系催化CO2与环氧化合物的反应首先是通过环氧化合物与RuCl3(2,2'-bipy)(CH3OH)中的甲醇分子发生配体交换引发的,经CTAC中的氯离子进攻环氧化合物开环、二氧化碳插入Ru—O键、分子内关环及消去生成环状碳酸酯.
The cycloaddition of CO2 with various epoxides to afford cyclic carbonates was investigated via the catalysis of ruthenium 2,2＇-bipyridine complex RuCl3（2,2＇-bipy）（CH3OH） and hexadecyl trimethyl ammonium chloride （CTAC）. The cyclic carbonate formation mechanism was studied by using electrospray ionization mass spectrometry （ESI-MS） in the case of cycloaddition of CO2 with propylene oxide （PO）. Two intermediate complexes, RuCl3（2,2＇-bipy）（PO） and RuCl3（2,2＇-bipy）（PC）, in the proposed reaction mechanism were successfully detected via ESI-MS measurement. Experimental results suggested that the initial coordination of epoxide is likely to occur first through the methanol ligand replacement in RuCl3（2,2＇-bipy）（CH3OH）. A nucleophilic attack of the chloride anion in CTAC on the less sterically hin- dered β-carbon atom of the coordinated epoxide is responsible for the epoxide ring-opening, CO2 succeedingly inserts into the Ru—O bond and ring-closure happens subsequently yielding the cyclic carbonate.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2010年第18期1871-1875,共5页
Acta Chimica Sinica
基金
河南省重点科技攻关(Nos.092102210172
102102210117)资助项目
