‘Metal Ion Electrophilic Catalysis’ in Ring-Opening Reactions of 1,2-Epoxides by Metal Halides in Ionic Liquids
作者:Dario Landini、Angelamaria Maia、Cecilia Betti
DOI:10.1055/s-2006-941562
日期:2006.6
Metal ion electrophilic catalysis (Li + > Na + K + ) has been found in ring-opening reactions of 1,2-epoxides 1-5 by metal halides MHal in ionic liquids. The results have been rationalized on the basis of a transition state where the cation M + stabilizes the negative charge developing on the oxygen atom of the oxirane ring while favoring the nucleophilic attack at the adjacent carbon by the ion-paired
金属离子亲电催化 (Li + > Na + K + ) 已在离子液体中金属卤化物 MHal 对 1,2-环氧化物 1-5 的开环反应中发现。结果已基于过渡态合理化,其中阳离子 M + 稳定环氧乙烷环氧原子上产生的负电荷,同时有利于离子对阴离子 Hal - 对相邻碳的亲核攻击。
An Efficient and Convenient
Protocol for Highly Regioselective Cleavage of Terminal Epoxides
to β-Halohydrins
作者:Bu-Bing Zeng、Tao Wang、Wen-Hao Ji、Zhong-Yu Xu
DOI:10.1055/s-0029-1217182
日期:——
An efficient and facile strategy for the cleavage of terminal epoxides to β-halohydrins using active magnesium halides is described. The conversion proceeds smoothly at room temperature with high regioselectivity and good yields even when sensitive functional groups are present.
Novel 3,5,and/or 6 substituted analogues of swainsonine processes for their preparation and their use as therapeutic agents
申请人:GlycoDesign Inc.
公开号:US20030236229A1
公开(公告)日:2003-12-25
The invention relates to novel 3, 5, and/or 6 swainsoninc analogues, processes for their preparation and their use as therapeutic agents. The invention also relates to pharmaceutical compositions containing the compounds and their use as therapeutics.
Novel 3, 5, and/or 6 substituted analogues of swainsonine, processes for their preparation and their use as therapeutic agents
申请人:GlycoDesign Inc.
公开号:US20020099065A1
公开(公告)日:2002-07-25
The invention related to novel 3, 5, and/or 6 swainsonine analogues, processes for their preparation and their use as therapeutic agents. The invention also relates to pharmaceutical compositions containing the compounds and their use as therapeutics.
Differently protected glycidol derivatives (with Bn, TBDPS, TBS and MPM groups) have been tested for regioselective ring opening with vinylmagnesium bromide in order to obtain useful five-carbon functionalised homoallylic alcohols. Careful choice of the reagents and experimental conditions allowed a general access to important chiral synthons for asymmetric synthesis. (C) 2003 Elsevier Science Ltd. All rights reserved.