Trihaloisocyanuric Acid/Triphenylphosphine: An Efficient System for Regioselective Conversion of Epoxides into Vicinal Halohydrins and Vicinal Dihalides under Mild Conditions
作者:Marcio de Mattos、Vitor de Andrade
DOI:10.1055/s-0035-1560408
日期:——
vicinal chloro-/bromohydrins and vicinal dihalides by reaction with the system trihaloisocyanuric acid/triphenylphosphine in acetonitrile under mild and neutral conditions. The reactions proceed smoothly in high yield at room temperature and at reflux, respectively, over a short time. A new synthetic method has been developed for the regioselective conversion of epoxides to vicinal chloro-/bromohydrins
Chlorinated iminium chlorides have been identified to promote the highly efficient and selective mono-chlorination of unsymmetrical vicinal diols. Vilsmeier reagent, namely, (chloromethylene)dimethyliminium chloride, enables highly reactive and regioselective chlorination of 1,2- and 1,3-diols featured one secondary benzylic hydroxy group and one primary aliphatic hydroxy group to give the corresponding
1,2-Ferrocenediylazaphosphinines2: A New Class of Nucleophilic Catalysts for Ring-Opening of Epoxides
作者:Tae-Jeong Kim、Seung Hwan Paek、Sang Chul Shim、Chan Sik Cho
DOI:10.1055/s-2003-38758
日期:——
1,2-Ferrocenediylazaphosphinines (1a-c) have been successfully employed as a new class of nucleophilic catalysts for ring-opening of a range of epoxides, their catalytic efficiency in terms of regioselectivity as well as chemical yield comparing well with the existing catalysts in the literature. In contrast, low enantiomeric excesses have been obtained from the reactions of meso-epoxides catalyzed by (R)-1.