Novel optically active polymers containing pendant proline moieties, poly{(−)-L- and (+)-D-proline-[5-(4′-tert-butylphenyl)-3-vinylpyridin-2-yl]amide}, were prepared through radical polymerization of (−)-L- and (+)-D-N-Boc-proline-[5-(4′-tert-butylphenyl)-3-vinylpyridin-2-yl]amide, followed by de-protection of the Boc group. Polarimetry and circular dichroism spectroscopy studies indicated that these polymers took chiral secondary structures. They were employed to catalyze the homogeneous asymmetric aldol reaction of 4-nitrobenzaldehyde with cyclohexanone. The polymeric catalysts showed obviously enhanced reaction rate but slightly reduced enantio-selectivity compared with (−)-L- and (+)-D-proline-[5-(4′-tert-butylphenyl)-3-vinylpyridin-2-yl]amide, the low molar mass counterparts. The lowered enantio-selectivity of the polymeric catalyst might be attributed to the antagonistic action of the configurational chirality of the side-group and the conformational chirality of the polymer backbone on the stereochemistry of aldol reaction.

中文翻译：

---

新型脯氨酸不对称羟醛反应的3-乙烯基吡啶新型螺旋聚合物的合成与性能

新型的含有侧链脯氨酸部分，聚{（-）- L-和（+）- D-脯氨酸-[5-（4'-叔丁基苯基）-3-乙烯基吡啶-2-基]酰胺}的光学活性聚合物是通过（-）- L-和（+）- D - N -Boc-脯氨酸-[5-（4'-叔）的自由基聚合制备-丁基苯基）-3-乙烯基吡啶-2-基]酰胺，然后将Boc基团脱保护。旋光和圆二色光谱研究表明，这些聚合物具有手性二级结构。它们被用来催化4-硝基苯甲醛与环己酮的均相不对称醛醇缩合反应。与（-）- L-和（+）- D-脯氨酸-[5-（4'-叔）-丁基苯基）-3-乙烯基吡啶-2-基]酰胺，低摩尔质量的对应物。聚合物催化剂对映选择性的降低可能归因于侧基的构型手性和聚合物主链的构型手性对醛醇缩合反应的立体化学的拮抗作用。