Study On Kinetic Resolution With Defatted Rapeseeds Or Ionic Liquid And Research On The Suzuki Reaction Conditions Of Cyanohydrins

Plant fruit contains a lot of enzyme, to use the plant fruits do a source has the certain advantage to explore the application of the enzyme of fruit in asymmetric synthesis. This thesis will use the rapeseed enzyme as a source to study it in three direction of ester, hydrolysis and go to the symmetry.First, some existing ketone is restored alcohol by LiAlH4; a series of alcohol with chiral carbon is got through the reaction of Grignard reagent with aldehyde. Substrate corresponding alcohols, reacted with with chiral carbon, and then acetic anhydride and Vinyl acetate as esterification reagent analyzed the rapeseed enzyme resolution effect.Secondly, racemic ester was made in with DMAP as catalyst, acetic anhydride as esterification reagent and the alcohol. Na2HPO4/NaH2PO4 as buffer, disstlled water as solvent analyzed the rapeseed enzyme hydrolysis effect in racemic ester.Third, A series of symmetry ester be reducted though the reaction of ester with and halogenated, to study the split effect by the condition of rapeseed as enzyme,and reaction conditions were optimized.Symmetry ester was reducted to symmetry alcohol by LiAlH4,to test rapeseed enzyme the selective esterification.We found there was no effect in esterification reaction of alcohol with chiral carbon with rapeseed enzyme.It was weak effect in hydrolysis reaction of common ester.But it had better result in hydrolysis reaction of symmetry ester, the yield can be reach 10% in such conditions: temperature of 20℃, pH 6.0 (Na2HPO4/NaH2PO4 as buffer).And,the result was more better to destroy symmetry especially in symmetry of double hydroxides, the yield can be reach 10%, without impurity and the two hydroxyl groups protected.We decided to put the ionic liquid into the split system, With the concept of recycling the catalyst and ionic liquid in use of chiral split. We found lipase PS-30,P-30,APF-12 had no catalytic effect in cyanohydrins and the compound contain a-CF3 with ionic liquid as solvent.Finally, we try to find a more stable compound after the cyanohydrins protected in order to adapt to exquisite Suzuki reaction condition.We got a type isomer when cyanohydrin with THP was stired under 0℃using p-toluenesulfonic acid as catalyst.It was more stable than the Acetyl group, and doesn't decomposed at room temperature or water-phase system or weak base, but it decomposed when the temperature reaches above 50℃.The yeild can reach 34% when 4-bromobenzaldehyde as substrate.Then,we obtain phenylbenzene either the expectation though the Suzuki coupling reaction. I think we should research other more stable protective group which is key to the success of this reaction.