Gas chromatographic study of solvent effect on asymmetric hydroformylation of vinyl acetate

Abstract

Optical 2-acetoxypropanal was the main product in the asym. hydroformylation of vinyl acetate with catalyst contg. chiral phosphine. The products of asym. hydroformylation in polar and nonpolar solvents were sepd. and characterized using capillary gas chromatog., gas chromatog./mass spectrometry, ORD and CD. By using GC with SE-52 glass capillary column, 6 components, in which 2-acetoxypropanal was 43%, were found in the catalytic reaction products using toluene as the nonpolar solvent, whereas 24 components were found with 24.6% of 2-acetoxypropanal using methanol as the polar solvent. There are more secondary reactions occurred in the polar solvent (methanol) than in the nonpolar solvent (toluene). The main product 2-acetoxypropanol was synthesized to give yield up to 83.1 mol% with selectivity 98.7 mol% and e.e value 7.2% in toluene; in methanol or without solvent (vinyl acetate as the reaction solvent) the main product 2-acetoxypropanal was synthesized to give yield, 59.2 mol% and 67.4 mol% with selectivity 60.2 mol% and 98.3 mol%, e.e. value 1.9% and 2.8%, resp. There are indications that in the asym. hydroformylation the yield, selectivity and e.e. value of reaction in toluene is higher than those of the reactions in methanol or without solvent. Significant solvent effect on the asym. hydroformylation of vinyl acetate was obsd. Nonpolar solvent is advantageous to its yield, selectivity and e.e. value. [on SciFinder (R)]