Cyclization of 1,1-Disubstituted Alkenes to Cyclopentenes
摘要:
A general method for the cyclization of an unactivated 1,1-disubstituted alkene such as 1 to the corresponding cyclopentene 5 is described. Bromination followed by the addition of strong base in the same pot gave the vinyl bromide 3, which reacted further in situ to give the alkylidene carbene 4. This then inserted 1,5 into a C-H bond to give the cyclopentene 5.
Metal-Free Three-Component Oxyalkynylation of Alkenes
作者:Yangshan Li、Ran Lu、Shutao Sun、Lei Liu
DOI:10.1021/acs.orglett.8b02954
日期:2018.11.2
An unprecedented (NH4)2S2O8 mediated metal-free three-componentalkene oxyalkynylation using H2O or alcohol as oxygenation agent is described. Mechanistic studies suggested that the reversed regioselectivity should be dictated by an alkene radical cation intermediate.
描述了前所未有的(NH 4)2 S 2 O 8介导的使用H 2 O或醇作为氧化剂的无金属三组分链烯氧基炔基化反应。机理研究表明,逆向的区域选择性应由烯烃自由基阳离子中间体决定。
Synthesis of novel macrocyclic peroxides by bis(sym-collidine)iodine (I) hexafluorophosphate-mediated cyclization of unsaturated hydroperoxides and unsaturated alcohols
Bis(sym-collidine)iodine (I) hexafluorophosphate-mediated cyclization of unsaturated hydroperoxides, prepared by a variety of different methods, afforded the corresponding 10- to 20-membered macrocyclic peroxides having two or three peroxide units located within one ring in moderate yields. By analogy, cyclization of unsaturated alcohols having one or two peroxide bond in the chain afforded the corresponding
POLAR GROUP-CONTAINING COPOLYMER, RUBBER COMPOSITION AND STUDLESS TIRE
申请人:Sumitomo Rubber Industries, Ltd.
公开号:EP2404944A1
公开(公告)日:2012-01-11
The present invention provides a polar group-containing copolymer which can provide a rubber composition and a winter tire achieving the abrasion resistance, performance on ice, and handling stability on dry roads in a balanced manner. The present invention relates to a polar group-containing copolymer obtainable by copolymerizing a conjugated diene compound and a polar group-containing vinyl compound, wherein the polar group-containing vinyl compound is a compound that has a polymerizable unsaturated bond and a polar group, wherein any one of carbon atoms forming the polymerizable unsaturated bond and a carbon atom linked to the polar group are connected to each other via at least one carbon atom, and wherein a cis content of the double bond portion of the conjugated diene compound in the polar group-containing copolymer is 80 mol% or more.