Cl^-促进CuCl2在水中选择性合成木糖醇二缩醛  

Cl^-promotion CuCl2 catalyst selectively synthesis xylitol diacetal in water

作　　者：汤琼[1] 李旭 董晋湘[1,2] TANG Qiong;LI Xu;DONG Jin-xiang(College of Chemistry and Chemical Engineering,Taiyuan University of Technology,Taiyuan 030024,China;School of Chemical Engineering and Light Industry,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]太原理工大学化学化工学院,山西太原030024 [2]广东工业大学轻工化工学院,广东广州510006

出　　处：《应用化工》2020年第3期531-535,共5页Applied Chemical Industry

基　　金：国家自然科学基金(21436008);"三晋学者"支持计划资助项目(2013);“万人计划”百千万工程领军人才(2016)。

摘　　要：以CuCl2为催化剂,木糖醇和辛醛为原料,通过在水溶液中加入NaCl高选择性的获得木糖醇二缩醛。不同水量加入CuCl2的催化体系中,紫外分光光度计分析反应后水溶液的结果表明,在325 nm处[CuClx]^2-x(x>2)配合物的浓度与反应的辛醛转化率和二缩醛选择性有关。为了调整水溶液中配合物的浓度,通过加入不同浓度的NaCl、不同阳离子氯化物、改变反应温度和时间,证明了Cl-的存在促进CuCl2在水中形成[CuClx]^2-x(x>2)配合物,而促进二缩醛的生成。与无水条件下的催化结果进行对比,在水和木糖醇质量比例为2.4,NaCl浓度为20%(质量分数),反应4 h,二缩醛的选择性为95.3%,与无水条件下获得最高选择性的数值接近(94.8%)。Using CuCl2 as a catalyst,xylitol and n-octanal as reactant,xylitol diacetal was synthesized with high selectivity in the presence of NaCl in water.When different amount of water was added into the reaction system in the presence of CuCl2,the after reaction aqueous was analyzed by UV-Vis spectroscopy.The concentration of [CuClx]^2-x(x>2) complex at 325 nm was related to the n-octanal conversion and diacetal selectivity of the reaction.In order to adjust the complex concentration of the aqueous,the different concentrations of NaCl and different cationic chlorides were taken,the reaction temperatures and time were changed.It was proved that the presence of Cl- promoted the formation of [CuClx]^2-x(x>2) complex in CuCl2 and which promoted formation of diacetal.Compared with the catalytic results under solvent-free conditions,the mass ratio of water to xylitol was 2.4,the concentration of NaCl was 20%,the reaction time was 4 h,the selectivity of diacetal was 95.3%.The value was closed to the highest obtained under solvent-free conditions(94.8%).

关 键 词：木糖醇 水溶液催化 选择性 缩醛反应 

分 类 号：TQ423.2[化学工程]