可调苯氧基修饰的聚(苯乙烯-苯乙烯基膦酸)-磷酸氢锆固载手性Mn^III(Salen)高效催化烯烃环氧化（英文）  

Chiral Mn~Ⅲ(Salen) supported on tunable phenoxyl group modified zirconium poly (styrene-phenylvinylphosphonate)-phosphate as an efficient catalyst for epoxidation of unfunctionalized olefins

作　　者：邹晓川[1,2] 石开云[1] 王存[1] 

机构地区：[1]重庆第二师范学院生物与化学工程系,重庆400067 [2]西南大学应用化学研究所,重庆市应用化学重点实验室,三峡库区生态环境教育部重点实验室,重庆400715

出　　处：《催化学报》2014年第9期1446-1455,共10页

基　　金：supported by the Basic and Frontier Research Project of Chongqing (cstc2013jcyjA50013);Scientific and Technological Research Program of Chongqing Municipal Education Commission (KJ131504);the Innovation Team Building at Institutions of Higher Education in Chongqing (KJTD201325)~~

摘　　要：使用不同空间位阻的苯氧链接手臂修饰的聚(苯乙烯基-苯乙烯膦酸)-磷酸氢锆轴向固载手性MnIII(Salen)催化剂(Cat1–Cat3),随后在间氯过氧苯甲酸(m-CPBA)为氧化剂的体系中考察了固载催化剂的催化性能.同时,在相同氧化体系下测试了一系列均相催化剂类似物(Cat4–Cat6).结果表明,在非均相条件下,可调变苯氧链接手臂的邻位取代基对催化剂活性起着重要作用,环氧化产物的对映选择性随着取代基位阻的增加而增大,但产物转化率有一定程度下降.此外,非均相催化剂即使在没有轴向助剂的参与下(通常需要添加,为了增大催化活性)仍然表现出非常高的催化活性,尤其对α-甲基苯乙烯反应,其对映选择性从6.8%增加到76.8%,转化率从19.8%上升到90.7%.制备的非均相催化剂11次的循环使用实验表明,在前5次使用后催化剂活性与对映选择性没有明显变化.We have developed a series of chiral MnI I（Salen） （chiral Jacobsen’s catalyst） catalysts that were axially supported onto zirconium poly（styrene-phenylvinylphosphonate）-phosphate through tunable phenoxyl linkers of varying steric hindrance, and evaluated their perfor-mance as catalysts （Cat1-Cat3） for the epoxidation of unfunctionalized olefins using m-chloroperbenzoic acid as an oxidant. The corresponding non-supported analogues （Cat4-Cat6） were also prepared and tested under similar conditions. The results demon-strated that the incorporation of substituents at the ortho-positions of the tunable phenox-yl linkers had a critical effect on the catalytic activity. Furthermore, the enantioselectivity increased as the steric hindrance imposed by the linker increased, although this also led to a decrease in the conversions under the same reaction conditions, especially for heteroge-neous epoxidation. The heterogeneous system also displayed high ee values and conver-sions in the absence of the axial additive N-methylmorpholine N-oxide, which is commonly required to improve the catalytic activity of epoxidation reactions, especially for the epox-idation ofα-methylstyrene. The reusability of the catalyst was also evaluated over 11 cata-lytic cycles, with no significant reduction observed in the catalytic activity or enantioselec-tivity after five runs.

关 键 词：聚(苯乙烯基-苯乙烯膦酸)-磷酸氢锆 手性Jacobsen催化剂 可调变苯氧链接基团 不对称非均相环氧化 

分 类 号：O621.251[理学—有机化学]