Synthesis of chiral quaternary ammonium polymers and their application to asymmetric reaction

虽然已经进行了大量的工作，使用侧链官能化的聚合物，只有有限数量的调查已经进行，以阐明使用主链官能化的聚合物。具有刚性和空间规则结构的主链手性聚合物催化剂可以在催化位点处具有更好限定的微环境，并且允许系统地改变其催化性能。我们合成了两种不同类型的含有季铵盐结构的手性主链聚合物。以该手性聚合物为催化剂，催化N-二苯基亚甲基甘氨酸叔丁酯的不对称烷基化反应，高选择性地合成了苯丙氨酸衍生物。

Although a substantial amount of work has been carried out using a side chain functionalized polymers, only a limited number of investigations have been performed to elucidate the use of main-chain functional polymers. The main-chain chiral polymer catalysts having rigid and sterically regular structure may have a better defined microenvironment at the catalytic sites and have allowed a systematic modification of their catalytic properties. We have synthesized two different types of chiral main-chain polymers containing quaternary ammonium salt structure. These chiral polymers were used as catalyst for asymmetric alkylation reaction of N-diphenylmethylidene glycine tert-butyl ester to give phenylalanine derivative in high level of enantioselectivity.