氯化铁催化邻炔基苯甲酸酯环化反应合成异香豆素

以12,-二氯乙烷为溶剂,氯化铁能有效催化邻炔基苯甲酸酯环化反应合成3-取代的异香豆素.考察了催化剂种类及用量和反应温度等因素对产率的影响,研究了不同结构底物对反应的容忍性.通过熔点测定、GC-MSI、R和NMR等手段对产物进行分析检测,表征了产物的结构.实验结果表明:当催化剂FeCl3的用量为50 mol%,以1,2-二氯乙烷作溶剂,在反应温度80℃的最佳条件下,邻苯乙炔基苯甲酸酯环化反应合成3-苯基异香豆素的产率高达96%.通过取代基对环化反应的影响研究发现,苯环上和炔烃上的官能团都不会影响反应的发生,尤其是底物的苯环上具有吸电子基团的产率要明显高于供电子基团,反应底物的适应范围比较广泛.该催化体系具有操作简单、价格低廉、选择性好等优点.

Synthesis of Isocoumains via Iron（HI） Chloride Catalyzed o-Alkynyl Benzoate Cyclization Reaction

O-alkynyl benzoate cyclization reaction to synthesize 3-substituted iscoumarins can be effectively catalyzed by Iron （ Ⅲ ） chloride with 1,2-dichloroethane as solvent. The effects of sorts and amounts of catalysts and raction temperature on the yields were investigated., the influence of structure of substrate on the reaction tolerance was researched as well. The structures of products were characterized by melting points, GC-MS and NMR. The results show that the yield of 3-phenyl-I H-isochromen-l-one is up to 96% under the optimum condition that the ammounts of catalyst FeC13 is 50 mmol%, solvent is CH2C1CH2C1 and temperature is 80~C. The effect of substitude group on cyclization reaction is researehed The results show that the yield of substrates with electron-withdrawing group on the aromatic ring are higher than those with electron-donating group. This catalytic system has advantages of a simple operation, low cost, and high selectivity.