C-C Formation Reactions Catalyzed By Hydrolase In Organic Medium

Enzymes are the catalysts of many chemical reactions, which can improve thereaction rate at least10times. Enzymatic have been widely used in modern organicsynthesis, because of their simple processing, high selectivity and mild reaction conditions.In the past decades, there were many studies about how to improve the catalytic activity,stereoselectivity and stability of enzyme in organic synthesis. All the studies include twomain aspects: the one is to improve the catalytic activity of enzyme from internalenvironment, contain: enzyme modification, site-specific mutagenesis of enzyme andimmobilized enzyme. The another is to improve the catalytic activity of enzyme from theoutside environment, contain: using organic medium, ionic liquids and supercritical fluidas reaction medium.This thesis mainly studied the C-C formation reactions catalyzed by hydrolase in theorganic phase. It is divided into five chapters.The first chapter introduces the research progress of enzymatic in the organic phase,ionic liquids and the supercritical fluid.The second chapter studies the Henry reaction of aldehyde and nitroalkane catalyzedby ANL (Amano Lipase A from Aspergillus niger). The effect of enzymes, reaction media,water content, enzyme loading, molar ratio of reactants and temperature on the reactionhave been studied to find the optimum condition of the reaction. Results showed that underthe optimum conditions, ANL can catalyze Henry reaction and the yield up to94%.The third chapter studies the Henry reaction catalyzed by papain (papain from papayalatex). After discussion of reaction conditions, found that the trend of Henry reactioncatalyzed by papain is the same with ANL. The yield of the reaction up to95%, whichshows protease and lipase may be have similar catalytic performance.The fourth chapter studies the synthesis5-benzylidene rhodamine derivativescatalyzed by papain. The results showed that the reaction can process in a relatively short time, and the best yield was86%after12h. But may be because the effect of sterichindrance, the papain have no catalytic effect for2-substituent aldehyde.The fifth chapter studies the Aldol reactions catalyzed by acylase. Base on thediscussion of enzymes, temperature, water content, enzyme loading, the best reaction areobtained. It showed that acylase can catalyze Aldol reaction of aldehydes and acetone withhigh efficient, and the yield up to88%.