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RESEARCH PRODUCT

First Evidence of Proline Acting as a Bifunctional Catalyst in the Baylis–Hillman Reaction Between Alkyl Vinyl Ketones and Aryl Aldehydes

Renato NotoAdriana Mossuto MarculescuSerena RielaMichelangelo GruttadauriaFrancesco GiacalonePaolo Lo Meo

subject

chemistry.chemical_classificationKetoneProlineAldehydeArylOrganic ChemistrySemi-empiricalcalculationSettore CHIM/06 - Chimica OrganicaBifunctional catalystCatalysisOrganocatalysichemistry.chemical_compoundchemistryOrganocatalysisOrganic chemistryAmine gas treatingBaylis–Hillman reactionPhysical and Theoretical ChemistryBaylis–Hillman reactionBifunctionalReaction mechanism

description

Proline in the presence of sodium hydrogen carbonate has been found to be an effective catalyst for the Baylis–Hillman reaction between methyl or ethyl vinyl ketone and aryl aldehydes. Screening of several amine catalysts showed that an ionizable carboxylic function directly linked to the secondary amine catalyst plays an important role in the synthesis of the desired product in good yield. The data obtained has allowed us to suggest, for the first time, that proline, sarcosine, pipecolinic acid and homoproline may act as bifunctional catalysts via a bicyclic enaminolactone species as intermediate. Quantum-mechanical calculations (PM3/COSMO and ab initio 3-21G/COSMO) support this mechanism and give more insight into the role of hydrogen carbonate.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

https://doi.org/10.1002/ejoc.200701112