文档介绍：摘要
高分子负载手性催化剂纳米粒子具有稳定高、溶剂适用性广、易于产物分离纯化、对环境危害小、易从反应体系中分离回收和重复使用等优点,受到了人们极大的重视。本文运用可逆加成断裂链转移聚合(RAFT)技术合成了一种新型高分子负载型手性催化剂纳米粒子。将催化剂应用于催化直接不对称Alodl反应,研究了反应条件对催化剂性能的影响。本文主要工作包括下列两部分:
聚0.***、表征:首先, 我们以羟脯氨酸为原料,使用三***乙酸为溶剂与***丙酰***反应合成了O.***,使用Boc保护氨基,.***;然后以二氧化硅纳米粒子为基质对其进行表面修饰,得到表面接有链转移试剂的官能团化二氧化硅,运用可逆加成断裂活性自由基聚合(RAFT)技术制备聚0.***丙
;,获得最终的固载手性催化剂二氧化硅纳米粒子。我们使用核磁共振、红外光谱、。
将制备的聚O.***,研究了此催化剂在直接不对称Aldol反应中的催化性能。实验结果表明,此催化剂在不对称Aldol反应中具有较好的催化活性和对映选择性。DMF作溶剂, 在0℃下使用10m01%催化剂催化对硝基苯甲醛与***的不对称Aldol反应,得到47% %的ee值。催化剂通过简单分离可重复使用。关键词:高分子负载手性催化剂,可逆加成断裂链转移聚合,O.***
酸,直接不对称Aldol反应
ABSTRACT
The supported catalyst has received much attention,its advantages is high stability,extensive suitability to solvents,easy separation and purification of product,lower environmental hazard,easy separation recovery from reaction system and reuse,and SO this thesis,a new hairy silica nanoparticles linking Poly(O-methyl acroloyl—L—hyp)chains had been synthesized by reversible addition fragmentation chain transfer(RAFT).And the catalyst had been used in asymmetric direct alodl reaction to investigate the optimized reaction paper could be divided into two parts.
Synthesis and characterization of hairy silica nanoparticles grafted with Poly(O-methyl acroloyl—L-hyp):O··methyl acroloyl—L-hyp hydrochioride Was prepared by the reaction of L··hyp and methyl carbonyl chloride in the trifluoro acetic polymerizable monomer N-substituted Boc-O-methyl acroloyl—L-hyp Was obtained from the N·boc protection of O-methyl acroloyl·L—hyp chain revesible agent Was attached on the surface of silica nanoparticles,and hairy silica nanoparticles linking polymeric chains with N··Boc··hyp were obtained from surface of silica by reversible addition fragmentation active radical polymerization(RAFT) ha