基于复合氯化剂CuCl_2·5/3NaCl·5/2Al_2O_3的1-氯-2-芳基乙炔的合成

Synthesis of 1-Chloro-2-aryl Ethyne Using CuCl_2·5/3NaCl·5/2Al_2O_3 as Composite Chlorinating Agent

直接使用CuCl2氯化芳基乙炔的反应通常存在着选择性差(有取代氯化和多种加成氯化的产物生成)、副产物多和分离困难等问题.描述了一种复合氯化剂(CuCl2·无机盐·载体)的制备以及基于该氯化剂取代氯化芳基乙炔的有效方法.首先通过一系列对比实验获得了CuCl2、载体和无机盐添加物的最佳配比.在此基础上考察了溶剂、复合氯化剂用量、反应温度诸因素对取代氯化反应的影响,提出了最佳反应条件:复合氯化剂为CuCl2·5/3Na Cl·5/2Al2O3,芳基乙炔与氯化剂的物质的量比为1∶3,溶剂为CH2Cl2,反应温度为35℃.在优化条件下,高产率(72%~99%)地合成了一系列1-氯-2-芳基乙炔目标产物1a^1n,并对这些化合物进行了表征.该方法反应条件温和、产率高、选择性好,并且适用于芳环上带有各种基团的底物.

An effective protocol for substitution chlorination was accomplished using a new composite chlorinating agent from CuC12, inorganic salt and carrier. The most appropriate ratio of each individual component of composite chlorinating agent was determined by comparative experiments. The optimal synthetic conditions for 1-chloro-2-aryl ethyne were obtained by the investigation of various factors, including solvents, the amount of composite chlorinating agents and reaction temperature. The mild and simple method allowed the formation of 1-chloro-2-aryl ethyne in up to 99% yields and showed good selectivities. Various substrates bearing inert or sensitive groups were tolerable for the present preparation. A plausible mechanism for the reaction was also proposed.