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Enantioselective hydrogenation of itaconic acid over cinchona alkaloid modified supported palladium catalyst

Paper ID Volume ID Publish Year Pages File Format Full-Text
43989 45998 2007 9 PDF Available
Title
Enantioselective hydrogenation of itaconic acid over cinchona alkaloid modified supported palladium catalyst
Abstract

The enantioselective hydrogenation of itaconic acid was studied over cinchona alkaloid-modified supported palladium catalyst in the presence of benzylamine as achiral base additive. The effect of several reaction parameters was investigated, such as the addition order of the additive, modifier and itaconic acid, hydrogen pressure, reaction temperature, amount of additive and modifier. Enantioselectivities up to 58% could be obtained by setting the appropriate conditions. The above results along with studies on the structure of the achiral amine additive, the chiral modifier and the substrate led to an interpretation of the increased enantioselection observed in the hydrogenation of itaconic acid in presence of benzylamine. According to this benzylamine plays role both on the surface of the catalyst and in the liquid phase by transforming the acid in bis-benzylammonium salt. Due to the salt formation the interaction with cinchonidine occurred through the conjugated carboxylic group, which led to increased enantioselectivity. Based on modifications in the substrate structure the effect of the unconjugated carboxylic group was also discussed.

Graphical abstractThe enantioselective hydrogenation of itaconic acid was studied over cinchona alkaloid-modified supported palladium catalyst in the presence of benzylamine. Benzylamine plays role both on the surface of the catalyst and in the liquid phase. It was shown that, by transforming the acid in bis-benzylammonium salt, the interaction with cinchonidine occurred through the conjugated carboxylic group, resulting in increased enantioselectivity. Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Benzylamine; Cinchona alkaloid; Enantioselective; Heterogeneous catalyst; Hydrogenation; Palladium; Itaconic acid
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Enantioselective hydrogenation of itaconic acid over cinchona alkaloid modified supported palladium catalyst
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 319, 1 March 2007, Pages 193–201
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
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