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Abstract: Regioselective Michael addition of purine derivatives to α,β-unsaturated carbonyl compounds could be catalyzed by d-aminoacylase amano (DA) in DMSO. The influence of reaction conditions on the Michael addition, including solvent, temperature, and enzyme concentration was systematically investigated. Then we extended this methodology to six structurally diverse purine derivatives and a variety of α,β-unsaturated carbonyl compounds. 21 Michael adducts were selectively synthesized in moderate to high yields. It is the first report on enzyme-catalyzed Michael addition for the preparation of purine derivatives. [Copyright &y& Elsevier]

Abstract: A novel strategy to perform Michael additions between 1,3-dicarbonyl compounds and α,β-unsaturated compounds was developed by the catalysis of hydrolase. We found that 11 hydrolase could catalyze the enzymatic Michael addition reaction to form the carbon–carbon bond. In 2-methyl-2-butanol d-aminoacylase showed high Michael addition activity. The influence of substrate and Michael acceptor structure on Michael addition was evaluated systematically. Some control experiments demonstrated that the active site of d-aminoacylase was responsible for the enzymatic Michael addition reaction. This novel Michael addition activity of hydrolase is of practical significance in expanding the application of enzymes and in the evolution of new biocatalysts. [Copyright &y& Elsevier]

Abstract: A novel and efficient enzymatic promiscuous protocol for aza-Michael addition of aromatic N-heterocycles to α,β-unsaturated compounds has been described. The reactions were catalyzed by promiscuous zinc-active-site acylase in organic solvent at 50°C. The strategy works with a broad range of N-heterocycles to afford the corresponding Michael adduct with good yields in several hours (0.5–6h). This catalytic promiscuity is the first example of metal-active-site enzyme-catalyzed aza-Michael addition for aromatic N-heterocycles. [Copyright &y& Elsevier]

Abstract: A novel and highly efficient protocol for Markovnikov’s addition using ionic liquid as a catalytic green solvent is described. The strategy is especially useful in the synthesis of N-heterocycle derivatives with biological activity. This reaction widens largely the applicability of ionic liquid in organic synthesis. [Copyright &y& Elsevier]