Synthesis of N-Aryl-4-arylhexahydroquinoline Derivatives by Reaction of Cyclic Enaminones with Arylidenemalononitriles in DMSO

The reaction of cyclic enaminones with arylidenemalono­nitriles was carried out in the presence of 13X molecular sieves in dimethyl sulfoxide. Under these mild reaction conditions, various bioactive N-aryl-4-arylhexahydroquinoline derivatives were obtained in high yields without the necessity of using transition-metal catalyst, organobase, or reflux conditions.

Synthesis of fused-tetrahydropyrimidines: one-pot methylenation–cyclization utilizing two molecules of CO2

A methylenation–cyclization reaction employing cyclic enaminones with primary aromatic amines and two molecules of CO2 to furnish fused-tetrahydropyrimidines has been developed.

Synthesis of tetrahydroindazol-4(5H)one and 7-thione from reaction of functionalized cyclic enaminones with hydrazine

Functionalized enaminones; 3-N-(aryl)amino-1--oxo-cyclohex-2-ene-2-dithiocarboxylates cyclohex-2-en-1-ones and 3-N-(aryl)amino-2-(N-aryl)thioamido-cyclohex-2-en-1-ones were obtained upon reaction of 3-N(aryl)amino-5,5-dimethyl-1-oxo-cyclohex-2-enes with carbon disulfide in presence of sodium hydroxide in DMSO, followed by methylation with dimethyl sulfate or with phenyl and p-bromophenyl isothiocyanates in toluene or under solvent-free condition, respectively. The cyclization of the dithioesters or the thioamides with hydrazine hydrate was accompanied by a displacement of the 3-N- arylamine moiety by a hydrazine group to give 6-hydrazino-4,4-dimethyl-1,3,4,5-tetrahydroindazole-7-thione or 3-N-(aryl)amino-4,5,6,7-tetrahydro-1H-indazole-4(5H)one respectively. Structure of the indazole derivatives formed was further confirmed from their reaction with acetone or p-nitrobenzaldehyde. The new structures were confirmed using 1HNMR, 13CNMR, 2DNMR, DEPT experiments and mass spectra.

A catalytic asymmetric interrupted Nazarov-type cyclization of 2-indolylmethanols with cyclic enaminones

A chiral phosphoric acid-catalyzed asymmetric interrupted Nazarov-type cyclization of C3-alkenyl-substituted 2-indolylmethanols has been established by using cyclic enaminones as nucleophiles.

Catalytic enantioselective and regioselective substitution of 2,3-indolyldimethanols with enaminones

2,3-Indolyldimethanols as a new class of indolyldimethanols have been designed, and the first catalytic asymmetric substitution of 2,3-indolyldimethanols has been established by using cyclic enaminones as nucleophiles.

Iodine as a New Catalyst for the Condensation of 2-Hydroxy-2,2′-bisindan-1,1′,3,3′-tetrone with Cyclic Enaminones: Synthesis of Spiro-dihydropyridine Derivatives under Acid-Free Conditions

Iodine has been used as a new catalyst for the synthesis of spiro-dihydropyridine derivatives by the condensation of cyclic enaminones and 2-hydroxy-2,2′-bisindan-1,1′,3,3′-tetrone.