Preparation of Dendritic and Non-Dendritic Styryl-Substituted Salens for Cross-Linking Suspension Copolymerization with Styrene and Multiple Use of the Corresponding Mn and Cr Complexes in Enantioselective Epoxidations and Hetero-Diels–Alder Reactions
作者:Holger Sellner、Jaana K. Karjalainen、Dieter Seebach
DOI:10.1002/1521-3765(20010702)7:13<2873::aid-chem2873>3.0.co;2-c
日期:2001.7.2
than 95% of the Salen incorporated being actually accessible for complexation (by elemental analysis). The polymer-bound Mn and Cr complexes were used as catalysts for epoxidations of six phenyl-substituted olefins (m-CPBA/NMO; products 22a-f), and for dihydropyranone formation from the Danishefsky diene and aldehydes (PhCHO, C5H11CHO, C6H11CHO, products 23a-c). There are several remarkable features
在使用TADDOL和BINOL之后,我们现在制备了带有两个至八个苯乙烯基的Salen衍生物(2、3、14、15、18、19、20、21),用于与苯乙烯交联共聚。Salen核要么衍生自(R,R)-二苯基乙二胺(3,15,19,21),要么衍生自(R,R)-环己烷二胺(2,14,18,20)。使用Suzuki(cf.1)或Sonogashira交叉偶联(cf.11)和/或用树状苯乙烯基取代的Fréchet型苄基进行酚醚化(cf.5、7)将苯乙烯基连接到水杨醛部分上分支溴化物。随后与二胺的缩合提供手性Salens。还制备了缺少外围乙烯基的相应Salens(参见12、13、16、17),用于比较均相溶液中的催化活性和聚苯乙烯中的催化活性。按照Itsuno和Fréchet的程序,苯乙烯和苯乙烯基Salens的交联自由基悬浮共聚,得到的珠子(直径约400微米)装有Mn或Cr(每克聚合物约0.2 mmo