Asymmetric Hydrogenation Of α,β-unsaturated Ester With Copper Catalyst

Since chirality has emerged as an important issue in many industrial production,especially in the areas connected to life sciences such as agrochemical, pharmaceutical,fragrance industries, extensive efforts have been made to obtain the pure enantiomers.Generally, the racemic mixture must be separated via chemical methods with a series ofcomplicated process to get single chiral compounds. But asymmetric catalytic reactionsonly use a small amount of chiral catalysts and synthesize a lot of chiral drugs. Thecatalytic asymmetric reduction of α, β-unsaturated carbonyl compounds offers a convenientand efficient method for preparing the optically active compounds bearing a stereogeniccenter at the β-position.Thiazide compounds and their derivatives are used widely as pharmaceuticals,pesticides, dyes and other fine chemical products, intermediates. On the basis of theresearch work previously, we found that thiazine compounds’ structure also has a hugespace in inhibiting the activity of aldose reductase. In this paper, we exploring theasymmetric catalytic hydrogenation conditions of thiazide unsaturated compounds,including the ligands, catalysts, additives, hydrogen source, solvents and other aspectsrespectively, choose the most suitable condition for the reaction finally. We got highenantioselectivities and reaction yield (up to94%and57%).Then we select1-tetralone,4-chromanone,1-indanone,3-coumaranone as the startingmaterials of the substrates. We will obtain four α,β-unsaturated carboxylic acid ester afterwittig-horner reaction, and use the selected optimal conditions above for the reaction, inorder to get high enantioselectivities (up to87%、82%、60%and65%) and reaction yield.So this kind of catalyst system is suitable for α, β-unsaturated esters.