CATIONIC POLYMERIZATION OF 1, 3—PENTADIENE INITIATED BY ORGANIC AZIDE/Et2AlCl

The cationic polymerization of 1, 3-pentadiene was initiated by the organic azide/Et_2 AlClinitiating system in CH_2Cl_2 and n-hexane. The polymerizations were also carried out in parallelwith organic chloride/Et_2AlCl and Et_2 AlCl alone for comparison. The Et_2 AlCl- induced polymer-ization gives a low yield while the polymerization initiated by organic chloride/Et_2 AlCl producesmainly insoluble product. In contrast, the polymerization with azide/Et,AlCl has a high conver-sion and the resulting polymer having a high molecular weight is totally soluble. The SEC spectraof the polymers have clearly shown the differences between these initiating systems.     

STUDY ON THE CATIONIC POLYMERIZATION OF 1, 3-PENTADIENE INITIATED BY AlCl_3/ALKYL HALIDE SYSTEMS

The cationic polymerizations of 1, 3-pentadiene were initiated by AlCl_3 in n-hexaneat 30℃ in the presence of alkyl halides, i.e., tert-butyl chloride, tert-butyl bromide andisobutyl chloride. The effects of these halides on the polymer yield, molecular weight,crosslinking reaction, cyclization and polymer microstructure, have been investigated. Twomain side reactions, crosslinking and cyclization, were suppressed and reduced by theaddition of the halides. The proportion of 1, 4 units of polymer chains was increasedby the presence of the halides, which reduced the polymer yield and the molecular weightof polymers.     

以7,7''''-二取代BINAP为配体不对称催化芳基硼酸对α,β-不饱和酮的1,4-加成反应

在不对称催化研究中,手性膦配体得到了广泛的应用,已有许多高效的手性膦配体报导,并应用于工业化生产手性化合物[1].BINAP是其中典型代表之一,近年来人们对BINAP进行了各种修饰并将其应用于不对称催化反应也时有报导[2].我们课题组应用近年发明的新型手性钒催化剂成功地用于偶联反应,合成了7,7'-二取代BINOL[3],进而合成了7,7'-二取代的BINAP系列配体1～5.     

顺－1，3－戊二烯的阳离子异构化聚合

顺－１，３－戊二烯的阳离子异构化聚合彭宇行，戴汉松，刘佳林，寸琳峰（中国科学院成都有机化学研究所，成都６１００４１）在阳离子聚合反应中，由于链增长过程中碳阳离子的不稳定性，可以导致异构化或重排反应￣［１］，这种异构化聚合（Ｉｓｏｍｅｒｉｚａｔｉｏｎｐ...