光促进温和条件下氯代烷烃与甲酸甲酯的羰基化反应

Photopromoted Carbonylation of Chloroalkanes with Methyl Formate under Ambient Conditions

研究了光促进温和条件下,非贵金属铜化合物、镉化合物催化氯代烷烃与甲酸甲酯的羰基化反应。结果表明,以CuCl_2、CuBr_2或CdI_2为催化剂,可实现氯代烷烃与甲酸甲酯的羰基化反应,得到相应的羧酸甲酯,如以CdI_2为催化剂,氯代环己烷的羰基化产物环己基甲酸甲酯的产率和选择性分别为64%和65%;镉化合物CdCl_2或Cd(OAc)_2单独使用时,无催化活性,向反应体系中加入碘化物,羰基化反应可以顺利进行。MS分析表明I-在镉化合物催化体系中的作用是I-在光照下先原位取代氯代烷烃中的Cl-生成相应的碘代烷烃,然后再与甲酸甲酯进行羰基化反应。

The photopromoted carbonylation of chloroalkanes with methyl formate was carried out under ambient conditions catalyzed by copper and cadmium compounds. The corresponding esters were obtained with three catalysts, i.e. CuCl2, CuBr2 and CdI2, e.g. methyl cyclohexanecarboxylate from chlorocyclohexane was given with 64% yield and 65% selectivity under the catalysis of CdI2. On the other hand, the carbonylation did not occur with single CdCl2 or Cd（OAc）2 unless iodide was added. The MS analysis indicated that the role of iodide ion in the cadmium catalytic system was firstly to give the corresponding iodoalkanes via substituting chloride ion in chloroalkanes in situ, and then, the carbonylation performed under irradiation.