the anticoagulant racemic warfarin is synthesized by the michael addition of 4-hydroxycoumarin with benzalacetone in the present of equimolar amounts of imidazolium based ionic liquids [bmim] bf4 and [bmim] br and other reaction solvents such as h2o, pyridine and ammonia in five different tests. also synthesis of a derivative of warfarin (2-methyl-4-phenyl pyrano [3, 2-c] chromen-5(4h)-one) und...

The enantioselective Michael addition using water as both nucleophile and solvent has to date proved beyond the ability of synthetic chemists. Herein, the direct, enantioselective Michael addition of water in water to prepare important β-hydroxy carbonyl compounds using whole cells of Rhodococcus strains is described. Good yields and excellent enantioselectivities were achieved with this method...

an efficient synthesis of some novel coumarin derivatives via 1, 4- michael addition of indole to coumarin chalcones catalyzed by cellulose sulphonic acid (csa) under solvent free conditions is described. the corresponding michael addition products were obtained in good to excellent yield. the synthesized compounds were screened for their antibacterial activity against e. coli, s. aureus and an...

The first phosphine catalysed Michael addition of arylcyanoacetates to allenoates has been developed, and the β-selective products with a quaternary center were obtained in excellent yields. This unusual regioselectivity may open new opportunities to access interesting molecular structures.

Aza-Michael addition of amines, including aromatic and aliphatic amines, with α, β-unsaturated ketones was realized employing N-Heterocyclic Carbene (NHC) as organocatalyst, yielding β-amino ketones with up to 98% yield.

Catalytic asymmetric Michael additions with curcumin derivatives were achieved by a new series of tertiary amine-thiourea organocatalysts to afford the Michael adducts in high yields and excellent enantioselectivities.