The reactions of acetylenes with bromine in alcohols at 20–25 °C afford dibromodialkoxyalkanes in good yields together with variable amounts of dibromoalkenes. Similar treatment of phenylacetylene with copper(II) bromide gives only bromophenylacetylene and 2-phenyl-1,1,2-tribromoethylene, the latter being formed by dibromination of the former with copper(II) bromide.
乙炔与溴在 20-25 °C 的醇中反应以良好的收率提供二溴二烷氧基烷烃和不同数量的二溴烯烃。用溴化铜 (II) 对苯乙炔进行类似处理,仅得到溴苯乙炔和 2-苯基-1,1,2-三溴乙烯,后者通过前者与溴化铜 (II) 的二溴化反应形成。
Iron(III) catalyzed halo-functionalization of alkynes
作者:Bryant Catano、John Lee、Claudia Kim、David Farrell、Jeffrey L. Petersen、Yalan Xing
DOI:10.1016/j.tetlet.2015.05.039
日期:2015.7
Aromatic and aliphatic alkynes can be halo-functionalized to alpha,alpha-dihalodimethyl ketals catalyzed by FeCl3 in excellent yields. MeOH is used as a nucleophilic solvent and N-halosuccinimide as the halogen source for this efficient transformation. The resulting alpha,alpha-dibromodimethyl ketals can be converted to the corresponding alpha,alpha-dibromoketones by treatment with 8% FeCl3 in silica gel. (C) 2015 Elsevier Ltd. All rights reserved.