Selective Conversion of Epoxides to<i>vic</i>-Halo Alcohols and Symmetrical or Unsymmetrical Dihalides by Triphenylphosphine/2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in the Presence of Quaternary Ammonium Halides
A new method is described for the efficient and selective conversion of epoxides to vic-halo alcohols or symmetrical and unsymmetrical dihalides using PPh 3 /DDQ/F 4 NX (X = Cl, Br, I) as a mixed-reagent system.
Solvent-Free, Efficient, and High Regioselective Conversion of Epoxides to Symmetrical and Unsymmetrical <i>vic</i>-Dihalides Using Chlorodiphenylphosphine and N-Halosuccinimides
作者:Ghasem Aghapour、Asieh Afzali
DOI:10.1080/10426507.2010.509877
日期:2011.2.28
Abstract A new method is described for the efficient and high regioselective conversion of epoxides to symmetrical and unsymmetrical vic-dihalides in high yields using chlorodiphenylphosphine and N-halosuccinimides under solvent-free and neutral conditions and at room temperature. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and
Catalytic Chemo-, Regio-, Diastereo-, and Enantioselective Bromochlorination of Unsaturated Systems Enabled by Lewis Base-Controlled Chloride Release
作者:Alexandra E. Lubaev、Manjula D. Rathnayake、Favour Eze、Liela Bayeh-Romero
DOI:10.1021/jacs.2c04588
日期:2022.7.27
triphenylphosphine or triphenylphosphine oxide as Lewis basic activators. This metal-free, catalytic chemo-, regio-, and diastereoselective bromochlorination of alkenes and alkynes exhibits excellent site selectivity in polyunsaturated systems and provides access to a wide variety of vicinal bromochlorides with up to >20:1 regio- and diastereoselectivity. The precision installation of Br, Cl, and I in various
描述了一种用于不饱和体系的路易斯碱催化溴氯化反应的新策略,该策略在机制上与现有方法不同。该方法的新颖性在于使用亚硫酰氯作为潜在的氯源,并结合低至 1 mol% 的三苯基膦或三苯基膦氧化物作为路易斯碱性活化剂。这种烯烃和炔烃的无金属催化化学、区域和非对映选择性溴氯化反应在多不饱和体系中表现出优异的位点选择性,并提供了多种邻位溴氯化物,其区域选择性和非对映选择性高达 >20:1。通过简单地改变所使用的商业卤化试剂也可以证明 Br、Cl 和 I 在各种组合中的精确安装。尤其,2菲尔。