aza-Michael Addition Of Aromatic Amines Research Articles

Sodium trifluoroacetate mediated copper-catalyzed aza-Michael addition of α,β-unsaturated olefins with aromatic amines

We present a sodium trifluoroacetate (CF3CO2Na) mediated copper-catalyzed aza-Michael addition of aromatic amines with activated olefins under mild, aqueous reaction conditions. This simplistic protocol employs a copper catalyst (10 mol%) and water as solvent. This transformation occurs precisely with aromatic substituted amines containing both electron-donating (EDG) and electron-withdrawing (EWG) groups. A broad range of substrates were tested under the optimized conditions, which are producing good to moderate yields.

Copper-Catalyzed Aza-Michael Addition of Aromatic Amines or Aromatic Aza-Heterocycles to α,β-Unsaturated Olefins.

A highly efficient and mild Cu-catalyzed conjugate addition reaction of aromatic amines and aromatic aza-heterocycles to α,β-unsaturated olefins is described. The transformation is promoted by 3-7 mol % of a Cu complex generated in situ from a mixture of inexpensive CuCl, a readily available phosphine or imidazolium salt, and KOt-Bu at ambient temperature. A wide range of β-amino sulfone, β-amino nitrile, and β-amino carbonyl compounds is efficiently and selectively synthesized in high yields (62-99%).

Synthesis, Characterization and Catalytic Application of MCM 41 Supported Phenanthrolinium Dibromide Catalyst for Aza-Michael Addition Reaction in Aqueous Medium

MCM-41 immobilized phenanthrolinium dibromide (phen-MCM-Br2) was easily prepared and applied as an efficient heterogeneous catalyst for aza-Michael addition of aromatic amines to α,β-unsaturated nitriles and nitro compounds in water. The catalyst was characterized by CHN, TGA, FT-IR, SEM, EDAX, XRD, BET, and TEM. It could be simply recovered and reused several times without significant loss of catalytic activity.

Synthesis and Antimicrobial/Cytotoxic Assessment of Ferrocenyl Oxazinanes, Oxazinan-2-ones, and Tetrahydropyrimidin-2-ones

3-Arylamino-1-ferrocenylpropan-1-ones, prepared through aza-Michael addition of aromatic amines to 1-ferrocenylpropenone, were transformed into the corresponding 1,3-amino alcohols upon NaBH4-mediated carbonyl reduction. The latter amino alcohols were deployed as eligible substrates for the synthesis of a variety of ferrocene-containing heterocycles including 1,3-oxazinanes, 1,3-oxazinan-2-ones, and tetrahydropyrimidin-2-ones, which were subsequently evaluated for their antimicrobial and cytotoxic activities.

An environmentally benign protocol: catalyst-free Michael addition of aromatic amines to α,β-unsaturated ketones in glycerol

Glycerol was used as a reaction medium as well as promoter for aza-Michael addition of aromatic amines to electronic deficient α,β-unsaturated ketones. Various aromatic amines can react smoothly with chalcone, 2-cyclohexen-1-one, 2-cyclopenten-1-one, and ethyl vinyl ketone to achieve good to excellent yields in the absence of any catalyst.

Chiral Phosphoric Acid Catalyzed Enantioselective Aza-Michael Addition of Aromatic Amines to Nitroolefins

Abstract Chiral phosphoric acid was found to be an effective organocatalyst in the enantioselective aza-Michael addition of aromatic amines to nitroolefins giving the corresponding β-nitroamine products in good yields (65%-95%) with moderate to good enantiomeric excess (16%-70%). This study represents the first example of a chiral phosphoric acid catalyzed asymmetric aza-Michael addition reaction.

Green, efficient and practical Michael addition of arylamines to α,β-unsaturated ketones

The aza-Michael addition of aromatic amines to α,β-unsaturated ketones was carried out effectively at room temperature in good to excellent yields without any catalyst or solvent. It was significant that part of adducts could be collected in almost quantitative yield without column chromatography. This procedure offered a green, efficient, and practical approach for the synthesis of β-amino ketones.

An effective aza-Michael addition of aromatic amines to electron-deficient alkenes in alkaline Al 2O 3

Aza-Michael addition of aromatic or aliphatic amines with various electron-deficient alkenes was performed using alkaline Al 2O 3 as solid media at room temperature afforded the corresponding Michael addition products in good to excellent yields. The alkaline Al 2O 3 can be easily recovered and reused.

Green and efficient aza-Michael additions of aromatic amines to α,β-unsaturated ketones catalyzed by DBU based task-specific ionic liquids without solvent

The DBU (1,8-Diazabicyclo[5.4.0]undec-7-ene) derived task-specific ionic liquids [DBU][Lac] (1,8-diazabicyclo[5.4.0]-undec-7-en-8-ium lactate), [DBU][Ac] (1,8-diazabicyclo[5.4.0]-undec7-en-8-ium acetate) and [DBU][Tfa] (1,8-diazabicyclo[5.4.0]-undec-7-en-8-ium trifluoroacetate) were synthesized. Among the three novel ionic liquids, [DBU][Lac] was found to have the highest catalytic activity for aza-Michael addition of aromatic amines to α,β-unsaturated ketones. The protocol can give good to excellent products yields and has advantages such as readily work-up and good reusability, which makes this method quite attractive.

A route to functionalized pyrimidines from carbohydrates via amine-driven dehydrative ring transformations

A novel and expeditious synthetic protocol for functionalized pyrimidines using unprotected aldoses as biorenewable resources is reported. The synthesis involves aza-Michael addition of aromatic amines to aldose-derived 1,3-oxazin-2-ones(thiones) followed by dehydrative ring transformation to afford 4-polyhydroxyalkylpyrimidin-2-ones(thiones) in excellent yields. This is a one-pot Montmorillonite K-10 clay-catalyzed amine-driven process proceeding under solvent-free microwave irradiation conditions.

Highly efficient aza-Michael reactions of aromatic amines and N-heterocycles catalyzed by a basic ionic liquid under solvent-free conditions

A task-specific basic ionic liquid, [Bmim]OH, has been introduced as a catalyst for the aza-Michael addition of aromatic amines and N-heterocycles to cyclic or acyclic ketones under neat conditions. The catalyst can be recycled for subsequent reactions without any appreciable loss of efficiency.