Research on Bioreduction of Saturated Aliphatic Aldehydes with α-chiral Carbon Centre
|School||Huazhong University of Science and Technology|
|Keywords||Baker's yeast Asymmetric reduction 2 - phenylpropionaldehyde alpha - chloro- n-butyraldehyde alpha - chloro- benzene, acetaldehyde|
The biocatalytic has become very important to today 's asymmetric synthesis method , currently baker's yeast as a biocatalyst asymmetric reduction reaction of the ketone compound , has become an effective method of producing an optically active alcohol compound . However, not much research on baker's yeast catalytic reduction of aldehydes , and most of the alpha , beta- unsaturated aldehydes , and the chiral carbon -containing alpha - unsaturated aldehydes has been reported rarely . The completion of the thesis research of the the part containing alpha - chiral carbon atoms saturated aliphatic aldehydes biological reduction reaction . A detailed examination of the bread yeast catalyzed reduction of 2 - phenyl propanal reaction to study the reaction time , the reaction temperature, the types of bread yeast , substrate concentration , pH value of the solution , additives , solvent system and other factors for the reaction affected. Found Angel Yeast culture fresh yeast biocatalyst obtained chloroformate was added to ethyl acetate as the inhibitor , 2 - phenyl - propionaldehyde can be converted to a high ee values ??(64% in phosphate buffer pH 8 ) and conversion rate (65% ) of ( S ) -2 - phenyl-1 - propanol. Another interesting result is to improve the ee value of the reduction product produced by the reaction with the substrate 2 , - increase of the concentration of phenyl propanal . Meanwhile, also on the synthesis of alpha - chlorinated aldehyde and alpha - bromo- aldehyde , respectively, using L- proline and prolinamide hexahydro- pyridine as catalyst , NCS and NBS as the halogenating agent , for the n-butyraldehyde , 3 - methyl butanal , n-heptyl aldehyde, phenyl acetaldehyde , and phenylpropyl aldehyde alpha - chloro and alpha - bromo- Wherein the use of L- proline can be obtained a very good yield , the number of grams above the alpha - chloro / bromo- aldehyde . Synthesis of alpha - chloro- n-butyraldehyde and alpha - chloro- phenyl acetaldehyde as a substrate , preliminary investigated the catalytic reduction of the bread yeasts . In addition, the synthesis of hetero atoms such as oxygen and nitrogen, sulfur aldehydes attempt. Use pyridinium salts of PCC , respectively oxidizing agent such as NaIO4 , CrO3 glycol ether , 3 - methoxy- 1, 2 - propanol, 3 - phenoxy 1,2 - propanol , 3 - benzyloxycarbonyl yl 1,2 - 2 -propanol , and a nitrogen-containing hetero atom , a sulfur primary alcohol oxidation .