Cationic Ring-Opening Polymerization of Optically Active N-Substituted Cyclic Thiourethanes
作者:Atsushi Nagai、Bungo Ochiai、Takeshi Endo
DOI:10.1021/ma049114b
日期:2004.10.1
polythiourethanes. The molecular weight of the polymers can be controlled by the ratio of the monomers to the initiator and the molecular weight distributions are narrow (Mw/Mn < 1.15) similar to the previously reported polymerization of a cyclic thiourethane [4(S)-(methoxycarbonyl)-1,3-oxazolidine-2-thione (SL)]. The polymerization rates are on the order of SL > BnSL > BzSL > AcSL, which agrees well
N-取代的环状硫代氨基甲酸酯[4(S)-(甲氧基羰基)-N-苄基-1,3-恶唑烷-2-硫酮(BnS L),4(S)-(甲氧基羰基)-N-苯甲酰基-1,3-恶唑烷-2-硫酮(BZS大号),和4(小号) - (甲氧羰基) - ñ -乙酰基-1,3-恶唑烷-2-硫酮(ACS大号])购自合成升-丝氨酸甲酯盐酸盐,并通过使用三氟甲磺酸甲酯聚合,得到相应的定义明确的聚硫代氨基甲酸酯。聚合物的分子量可以通过单体与引发剂的比例来控制,分子量分布较窄(M w / M n <1.15),类似于先前报道的环状硫代氨基甲酸酯的聚合[4(S)- (甲氧基羰基)-1,3-恶唑烷-2-硫酮(S L)]。聚合速率为S L>BnS L>BzS L>AcS L。,这与单体(S L,BnS L BzS L和AcS L)的硫代羰基部分的亲核性非常吻合。来自N-取代单体的聚合物的CD光谱中的Cotton效应显示出与poly(S L
Method of producing a polythiourethane and method of producing a graft polymer
申请人:Nagai Atsushi
公开号:US20050250926A1
公开(公告)日:2005-11-10
A polythiourethane is produced by polymerizing a compound represented by formula (I) in the presence of a compound represented by formula (II)
in which R
1
represents a methyl group;
amide bond among a sea of other amides is a significant and long-standing challenge. Although the use of twisted amides has been demonstrated for modifications of inert C–N amide bonds, none of these methods can selectively activate a particular amide bond for C–Cbond formation in the presence of similar amides. Using density functional theory as a guide, we report the first site-selective C–C bond