液-液相转移催化Wittig-Horner反应合成二苯乙烯

针对当前二苯乙烯的合成工艺存在反应时间长、收率低、产品分离成本高等问题,提出了液-液相转移催化合成二苯乙烯的新方法。详细研究了各种因素如搅拌速率、催化剂种类与用量、有机溶剂种类与体积、氢氧化钠浓度和温度对相转移催化反应体系的影响,并探讨了液-液相转移催化反应机理。以用量为6%的四丁基溴化铵作催化剂,在甲苯/50%的烧碱溶液体系中于45℃、1 200 r/分钟下反应80分钟,苯甲醛的转化率为92.6%,并且反应产物全为E式构象。研究结果表明:液-液相转移催化Wittig-Horner反应为萃取机理,这为二苯乙烯母体结构化合物的绿色工业化生产提供了新的合成路径。

Synthesis of Stilbene by Wittig-Horner Reaction with L-L PTC

To counter problems such as long reaction time, low yield, high cost of separating product and so on, a novel synthetic method of liquid-liquid phase transfer catalysis （ L-L PTC） for synthesizing stilbene was presented. The effects of agitation speed, kinds and amounts of catalysts, kinds and volumes of organic solvents, concentration of NaOH and temperature on catalysis reaction were investigated in detail, and a mechanism of Wittig-Horner reaction was given. The conversion of benzaldehyde could reach 92.6% when dosage of catalyst tetra-n-butylammonium bromine （TBAB） was 6%, reaction at 45 ℃ with 1200 rpm for 80 minutes in a toluene / aqueous NaOH （wt 50% ） system; all product were E-alkenes. The results showed that reaction of L-L PTC was Starks extraction mechanism rather than Makosza interfacial mechanism. The study provided a new synthetic method for green industrial production of stilbenoid.