Carbonate phosphonium salts as catalysts for the transesterification of dialkyl carbonates with diols. The competition between cyclic carbonates and linear dicarbonate products
作者:Maurizio Selva、Alessio Caretto、Marco Noè、Alvise Perosa
DOI:10.1039/c4ob00655k
日期:——
At 90–120 °C, in the presence of methylcarbonate and bicarbonate methyltrioctylphosphonium salts as catalysts ([P8881][A]; [A] = MeOCO2 and HOCO2), the transesterification of non-toxic dimethyl- and diethyl-carbonate (DMC and DEC, respectively) with 1,X-diols (2 ≤ X ≤ 6) proceeds towards the formation of cyclic and linear products. In particular, 1,2-propanediol and ethylene glycol afford propylene-
在90–120°C下,在存在碳酸甲酯和碳酸氢盐的情况下,甲基三辛基phosph盐作为催化剂([P 8881 ] [A]; [A] = MeOCO 2和HOCO 2),无毒碳酸二甲酯和碳酸二乙酯进行酯交换反应用1(DMC和DEC,分别地),X -diols(2≤ X ≤6)朝向环状和线性产物的形成进行。特别地,1,2-丙二醇和乙二醇选择性地提供碳酸亚丙酯和碳酸亚乙酯,产率分别高达95%和90%。同时,DMC与高级二醇反应,例如1,3-丁二醇,2-甲基-1,3-丙二醇,1,3-丙二醇,2,2-二甲基,1,3-丙二醇,1,4-丁二醇和1,6-己二醇产生线性C 8 –C10种通式为MeOC(O)O ~~~ OC(O)OMe的二碳酸酯几乎是排他的产物。值得注意的是,这些二碳酸酯衍生物否则不能通过其他常规的碱催化方法以高收率获得。在1,3-二醇中,唯一的例外是2-甲基2,4-戊二醇产生相应的环状碳酸酯