专业文献

2011

文章编号: 0253-9837(2011)01-0065-05

Chinese Journal of Catalysis

国际版DOI: 10.1016/S1872-2067(10)60161-1

Vol. 32 No. 1

研究论文: 65~69

Pd(OAc)2/(S)-P-PHOS 催化的丙烯与 CO 交替共聚合

成手性功能高分子

王来来, 贾小静, 万 博

中国科学院兰州化学物理研究所羰基合成与选择氧化国家重点实验室, 甘肃兰州 730000

以丙烯和 CO 为原料, Pd(OAc)2/(S)-P-PHOS 为手性催化剂, 在有机溶剂中, 经不对称交替共聚反应合成了手性功能高分子摘要：

聚酮. 当过量的还原剂 LiAlH4 和 NaBH4 分别还原聚酮时, 手性聚醇产率达 90%; 当 NaBH4/羰基摩尔比分别为 0.5, 1 和 2, 紫外光谱 (200~400 nm) 检测证明, 手性聚酮中羰基的 29%, 71% 和 81% 分别被还原; 使用过量的还原剂 BH3·THF 时, 手性聚酮中羰基只能部分被还原. 手性聚醇的数均分子量比手性聚酮的低, 产物手性聚醇的摩尔旋光度随还原反应条件而变化. 关键词：醋酸钯; 手性双膦配体; 丙烯; 一氧化碳; 手性聚酮; 还原剂; 手性聚醇 中图分类号：O643 文献标识码：A

Synthesis of Chiral Functionalized Polymers by Alternating Copolymerization of

Propene and CO Using the Pd(OAc)2/(S)-P-PHOS Catalyst

WANG Lailai*, JIA Xiaojing, WAN Bo

State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics,

…… 此处隐藏0字 ……

Chinese Academy of Sciences, Lanzhou 730000, Gansu, China

Abstract: Pd(OAc)2 (palladium acetate)/(S)-P-PHOS ((S)-2,2′,6,6′-tetramethoxy-4,4′-bis(diphenyl)phosphino)-3,3′-bipyridine) catalysis systems were applied to the alternating copolymerization of propene and CO in organic solvents to synthesize chiral polyketones. The di-astereoselective reduction of a chiral polyketone using excess LiAlH4 (lithium aluminum hydride) and NaBH4 (sodium borohydride) as re-ducing agents gave a new class of optically active polyalcohol and the product yield was more than 90%. In the presence of various amounts of NaBH4 (NaBH4/carbonyl molar ratio of 0.5, 1, and 2), quantitative measurements of the intensity of the carbonyl absorbance at 200–400 nm in the UV (ultraviolet) spectrum showed a reduction of 29%, 71%, and 81%, respectively, for the carbonyl groups. The use of excess BH3·THF (borane tetrahydrofuran complex) as a reducing agent resulted in a partial reduction of the carbonyl groups of the chiral polyke-tone. The molecular weight of the product was lower than that of the chiral polyketone and the molar optical rotations of the product varied with the reductive conditions.

Key words: palladium acetate; chiral diphosphous ligand; propene; carbon monoxide; chiral polyketone; reducing agent; chiral polyalcohol

The alternating copolymerization of olefins and CO has attracted considerable attention from both academia and industry over the last few decades [1]. Initially, the reaction occurred in the presence of a radical initiator using ethylene as a starting material. Several polymers incorporating a va-riety of heteroatom functionalities have been synthesized and the product C2H4/CO ratio has been found to be more than 1 [2]. The obtained products exhibit engineering plastic properties. In the 1980s, a class of highly active palladium

catalysts for this reaction (Scheme 1) were reported [3,4]. A terpolymer derived from ethene, propene, and CO became commercially available under the trade name Carilon. The alternating copolymers (olefin/CO = 1) have the highest possible concentration of reactive carbonyl groups, which can be chemically modified to new functional groups such as hydroxyl, cyano, amino, etc. Polyketones are also excel-lent starting materials for other classes of polymers such as polyalcohols [2], polyamines [5], polyoximes [2,6–8], poly-

Received 30 June 2010. Accepted 17 September 2010.

*Corresponding author. Tel: +86-931-4968161; Fax: +86-931-4968129; E-mail: wll@

Foundation item: Supported by the National Natural Science Foundation of China (20343005, 20473107, 20673130, 20773147) English edition available online at ScienceDirect (/science/journal/18722067).