title: Enzyme catalytic promiscuity: The papain-catalyzed Knoevenagel reaction.
abstract: Papain as a sustainable and inexpensive biocatalyst was used for the first time to catalyze the Knoevenagel reactions in DMSO/water. A wide range of aromatic, hetero-aromatic and α,β-unsaturated aldehydes could react with less active methylene compounds acetylacetone and ethyl acetoacetate. The products were obtained in moderate to excellent yields with Z/E selectivities of up to 100:0. This case of biocatalytic promiscuity not only widens the application of papain to new chemical transformations, but also could be developed into a potentially valuable method for organic synthesis.
authors.affiliation: School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Wen
authors.initials: W
authors.lastname: Hu
authors.forename: Zhi
authors.initials: Z
authors.lastname: Guan
authors.forename: Xiang
authors.initials: X
authors.lastname: Deng
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: He
mesh_terms: D000090:Acetoacetates / Q000737:chemistry / Q000378:metabolism; D000447:Aldehydes / Q000737:chemistry / Q000378:metabolism; D002384:Catalysis; D015394:Molecular Structure; D010206:Papain / Q000378:metabolism*; D010422:Pentanones / Q000737:chemistry / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D000090:Acetoacetates; D000447:Aldehydes; D010422:Pentanones; C008790:acetylacetone; D010206:Papain; C024840:ethyl acetoacetate