The multicomponent reaction of 2-nitroacetophenone (or nitroacetone), acetaldehyde diethyl acetal, ?-dicarbonyl compound, and ammonium acetate in an acetic acid solution allowed the acquisition previously undescribed 4-methyl-substituted derivatives 5-nitro-1,4-dihydropyridine satisfactory yields. oxidation obtained resulted corresponding 2,4-dimethyl-5-nitropyridines. In addition, for first ti...

      In order to investigate the effects of dimethylamino substituent at postion 2 of the dihydropyridine nucleus on its activity, dialkyl 1,4-dihydro-2-[2-(dimethy- lamino) ethyl]-6-methyl-4-(1-benzyl-2-alkylthio-5-imidazolyl)-3,5-pyrdinedicar- boxylates (6a-f) were synthesized. The synthesis was started from dialkyl 1,4- dihydro-2,6-dimethyl-4-(1-benzyl-2-alkylthio-5-imidazolyl)-3,5-pyridine...

The reaction of a sec-nitrodienamine 3 with aldehyde compounds afforded 2-substituted 3-nitro-1,2-dihydropyridines 5, providing a heterocyclic annulation reaction.

In the present paper, a direct quenching of radical species by a number of synthesized nitrosoaryl 1,4-dihydropyridines and their parent nitroaryl 1,4-dihydropyridines was determined in aqueous media at pH 7.4. These two series of compounds were compared with the C-4 unsubstituted 1,4-dihydropyridines derivatives and the corresponding C-4 aryl substituted 1,4-dihydropyridines derivatives. Kinet...

Diastereoselective Ugi reactions of DMAP-based aldehydes with α-amino acids and tert-butyl isocyanide were examined. The reactions of 4-(dimethylamino)-2-pyridinecarboxaldehyde with various α-amino acids afforded 2-substituted DMAP derivatives with low diastereoselectivity. On the contrary, reactions with 4-(dimethylamino)-3-pyridinecarboxaldehyde delivered 3-substituted DMAP derivatives with m...

Acid treatment of densely substituted 2-silyl-1,2-dihydropyridines provides a new and convenient entry to reactive azomethine ylides that can (1) be protonated and reduced with high stereoselectivity to give piperidines, (2) participate in [3 + 2] dipolar cycloaddition to give tropanes, and (3) undergo a Nazarov-like 6-π electrocyclization that upon reduction give 2-azabicyclo[3.1.0] systems.

Coupling of the N,N-dimethylacrylamides 6a-c with cyclopentadienide resulted in the formation of the substituted 3-dimethylamino-1,2-dihydropentalnenes 2a-c. Deprotonation followed by metallation with CpZrCl(3)·DME gave the substituted zirconocenes 12a-c. The reaction of 3-dimethylamino-1-methyl-dihydropentalene 2a with ZrCl(2)(NMe(2))(2)·2THF resulted in a unique coupling between a pair of the...

in order to investigate the effects of dimethylamino substituent at postion 2 of the dihydropyridine nucleus on its activity, dialkyl 1,4-dihydro-2-[2-(dimethy- lamino) ethyl]-6-methyl-4-(1-benzyl-2-alkylthio-5-imidazolyl)-3,5-pyrdinedicar- boxylates (6a-f) were synthesized. the synthesis was started from dialkyl 1,4- dihydro-2,6-dimethyl-4-(1-benzyl-2-alkylthio-5-imidazolyl)-3,5-pyridinedicar-...

An efficient three component reaction with enaminones, primary amines and aldehydes resulted in easy access to 1,4-dihydropyridines with different substituents at the 1-, 3-, 4- and 5-positions. Microwaves improved the reaction yield, reducing also considerably the reaction time and the amount of solvent used. Chiral primary amines gave chiral 1-substituted-1,4-dihydropyridines. The 4-(1-naphth...

Recently, a series of alkyl 2-substituted 3-(dimethylamino)prop-2-enoates and related enaminones have been prepared as versatile reagents for the preparation of various dehydroalanine derivatives, heterocyclic systems, and natural product analogues. In extension, chiral cyclic enamino lactams and lactones, derived from α-amino acids and (+)-camphor have been used in the synthesis of functionali...