The reactivity of phosphate esters. Reactions of diesters with nucleophiles
作者:A. J. Kirby、M. Younas
DOI:10.1039/j29700001165
日期:——
The reactions of a wide range of nucleophiles with a series of aryl methyl phosphate ester anions involve concerted nucleophilic displacement at phosphorus. The attack of neutral nucleophiles is slower than the corresponding reactions of both triesters and monoester monoanions. SN2(P) reactions involving the attack of anions on phosphate diester anions are observed, and are shown to be retarded by
多种亲核试剂与一系列芳基甲基磷酸酯阴离子的反应涉及在磷处的协同亲核取代。中性亲核试剂的进攻要比三酯和单酯单阴离子的相应反应慢。观察到涉及阴离子对磷酸二酯阴离子的攻击的S N 2(P)反应,并且显示出受阻约两倍。速率为100倍,这归因于不良的静电作用。对亲核试剂和离去基团的敏感性都很高,并且对反应性有一定的依赖性:它们显然也受到静电作用的影响。
PROCESS FOR PRODUCING POLYCARBONATES AND A COORDINATION COMPLEX USED THEREFOR
申请人:SK INNOVATION CO., LTD.
公开号:US20140249323A1
公开(公告)日:2014-09-04
The complex of the present invention containing an onium salt and a central Lewis acidic metal has a high catalytic activity at a high temperature for the copolymerization of an epoxide and carbon dioxide to produce a high molecular weight polycarbonate.
Copolymerization of carbon dioxide and propylene oxide by several metallosalen-based bifunctional catalysts
作者:Wenkai Zhu、Longchao Du、Siyu Qian、Qingsong Yang、Wanjie Song
DOI:10.1002/jccs.201800051
日期:2018.7
increase of temperature, both the catalyst efficiency and the molecular weight of the copolymer decrease for all the five complexes. The salen‐Co(III) complex demonstrated higher activity under mild conditions: reaction temperature at 30 °C, copolymerization time of 24 hr, and 2 MPa of CO2 pressure. The DSC curve indicated that the PPC by the salen‐Co(III) complex has the highest Tg of 46.19 °C. DTGA
new Salen‐Co(III) bifunctionalcatalysts were synthesized for the first time, and they were studied to catalyze the copolymerization of CO2 and propyleneoxide (PO)/cyclohexene oxide (CHO). At the same time, the effects of reaction conditions (electronic effect, temperature, time) on catalytic activity and selectivity were investigated. The results show that the Salen‐Co(III) complexes with electron‐withdrawing
Isopropenyl chloroformate (IPCF) was used for preparation of mixed carbonates (Aryl and isopropenyl) which are very suitable reagents for active ester synthesis of amino acid derivatives ( Boc derivatives In particular).