用气相色谱法研究乙酸乙烯酯不对称氢甲酰化反应中溶剂的影响

用毛细管气相色谱、色－质谱和旋光色散及圆二色性谱仪等方法对乙酸乙烯酯在非极性和极性溶剂中的不对称氢甲酰化反应产物进行分离和鉴定。实验结果表明，在非极性溶剂中反应的收率、选择性、光学收率ｅ．ｅ．值（ｅｎａｎｔｉｏｍｅｒｉｃｅｘｃｅｓｓ）均比极性溶剂中的结果为好。由此探讨了不对称氢甲酰化反应中溶剂的影响。

Gas Chromatographic Study of Solvent Effect of Vinyl Acetate in Asymmetric Hydroformylation

Optical 2-acetoxypropanal was the main product in the asymmetric hydroformylation of vinyl acetate with catalyst containing chiral phosphate. The products of asymmetric hydroformylation in polar and non-polar solvents were separated and characterized by use of capillary gas chromatography, gas chromatography/mass spectrometry, optical rotators dispersion and circular dichroism.According to the experiments using SE-52 glass capillary column,6 components,in which 2-acetoxypropanal was 43%,were found in the catalytic reaction with non-polar solvent toluene; whereas 24 components with 24.6 % of 2-acetoxypropanal in polar solvent methanol. It is quite evident that there are more secondary reactions occurred in polar solvent (methanol) than in non-polar solvent(toluene). The main product 2-acetoxypropanal was synthesized to give yield up to 83.1 mol% with selectivity 98.7 mol% and e.e.value7.2% in solvent toluene;but in polar solvent methanol and without solvent(vinyl acetate as the reaction solvent itself).The main product 2-acetoxypropanal was synthesized to give yield,59. 2mol% and 67.4 mol% with selectivity 60.2 mol% and 98. 3 mol% ,e. e. value 1. 9% and 2. 8% respectively. There are indications that in the asymmetric hydroformylation the yield,selectivity and.e.e.value of reaction in solvent toluene is higher than those of the reactions in solvent methanol and without solvent.That shows the notable effect of solvent in the asymmetric hydroformylation of vinyl acetate.In the catalysis,using non-polar solvent is advantageous to its yield,selectivity and e.e. value.