Synthesis of cyclic polymers:: Ring-expansion reaction of cyclic S-dithioester with thiiranes
Synthesis of cyclic polymers:: Ring-expansion reaction of cyclic S-dithioester with thiiranes
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DOI：
10.1021/ma047642h
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发表时间：
2005-07-12
期刊：
影响因子：
5.5
通讯作者：
Nishikubo, T
中科院分区：
文献类型：
--
作者：
Kudo, H;Makino, S;Nishikubo, T
以TBAC为催化剂，在NMP中考察了等摩尔环二硫酯1与3-苯氧丙烯硫醚（PPS）（环二硫酯1/PPS = 1/2）的扩环反应24 h。结果表明，PPS插入环二硫酯时发生了分子间酯交换反应，得到了M(n)s = 3600 ~ 8900的环状聚合物，产率为80 ~ 96%。所得环状聚合物的结构通过H-1 NMR、C-13 NMR IR和MALDI TOF-MS谱分析得到了证实。将多余的聚苯硫醚连续插入到环二硫酯（环二硫酯1/聚苯硫醚= 1/50）中，定量地得到相应的m = 42 000、M-w/M-n = 4.50的环多硫醚，收率为96%。
The ring-expansion reaction of equimolar cyclic dithioester 1 with 3-phenoxypropyrene sulfide (PPS) (cyclic dithioester 1/PPS = 1/2) was examined in the presence of TBAC as a catalyst in NMP for 24 h. It was found that intermolecular ester-exchange reaction occurred during the insertion reaction of PPS into cyclic dithioesters, and cyclic polymers with M(n)s = 3600-8900 were obtained in 80-96% yields. The structures of the obtained cyclic polymers were confirmed by the H-1 NMR, C-13 NMR IR, and MALDI TOF-MS spectroscopy. The continuous insertion reaction of excess PPS into cyclic dithioester (cyclic dithioester 1/PPS = 1/50) was also examined, and it was found that the insertion reaction proceeded quantitatively to afford the corresponding cyclic polysulfide with M. = 42 000 and M-w/M-n = 4.50 in a 96% yield.