Catalysts for asymmetric-induction polymerization of benzofuran. II. Properties and catalyses of some binary systems containing the menthoxy group
Catalysts for asymmetric-induction polymerization of benzofuran. II. Properties and catalyses of some binary systems containing the menthoxy group
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苯并呋喃不对称诱导聚合催化剂。
DOI：
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发表时间：
1967
期刊：
影响因子：
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通讯作者：
J. Furukawa
中科院分区：
文献类型：
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作者：
Y. Hayakawa;T. Fueno;J. Furukawa
已经发现，由铝氧化物和（−）-薄荷氧基三乙基锡、-锗或-硅组成的等摩尔二元体系对于苯并呋喃在甲苯中在−78°C下的不对称诱导聚合是有效的。所得聚苯并呋喃的比旋度[α]D范围为+10°至+40°，取决于聚合条件以及构成薄荷氧基化合物的金属原子。1：1的乙基氯化铝-薄荷醇体系对相同的聚合也是有效的。经证实，这些二元体系容易发生交换反应，得到二聚薄荷氧基二氯化铝，（Men* OAlCl 2）2，熔点72-75°C。结晶二聚体的甲苯溶液使苯并呋喃聚合成[α]D值高达+79.4°的高聚物，尽管用二聚体聚合比用母体二元混合物聚合慢得多。所有这些结果导致的结论，我们的多组分系统的真正的催化物种是最有可能的二聚薄荷氧基二氯化铝。
It has been found that the equimolar binary system consisting of aluminum trichloride and (−)-menthoxytriethyltin, -germanium or -silicone is effective for the asymmetric-induction polymerization of benzofuran in toluene at −78°C. The specific rotation [α]D of the resultant polybenzofuran ranged from +10° to +40°, depending on the polymerization conditions as well as the metal atoms constituting the menthoxy compounds. The 1:1 ethylaluminum dichloride—menthol system was also effective for the same polymerization. It was confirmed that these binary systems easily undergo an exchange reaction, giving a dimeric menthoxyaluminum dichloride, (Men*OAlCl2)2, m.p. 72–75°C. A toluene solution of the crystalline dimer polymerized benzofuran into a high polymer having as large an [α]D value as +79.4°, although polymerization with the dimer was much slower than that with the parent binary mixtures. All these results lead to the conclusion that the true catalytic species of our multicomponent systems is most probably the dimeric menthoxyaluminum dichloride.