ABSTRACT
Regioselective synthesis of multisubstituted 4-amino- and 6-amino-2-iminopyridines has been developed via the copper-catalyzed three-component reaction based on the reaction conditions selection. The reaction of sulfonyl azides, alkynes, and 2-[(amino)methylene]malononitriles catalyzed by copper(I) iodide in tetrahydrofuran at room temperature afforded substituted 4-amino-2-iminopyridines, whereas, in N,N-dimethylformamide at 50 °C under N2, it generated substituted 6-amino-2-iminopyridines as predominant products.
Subject(s)
Copper/chemistry , Nitriles/chemistry , Pyridines/chemical synthesis , Solvents/chemistry , Catalysis , Molecular Structure , Pyridines/chemistryABSTRACT
A facile and efficient route for the homogeneous and highly stereoselective monohydration of substituted methylenemalononitriles to (E)-2-cyanoacrylamides catalyzed by copper(II) acetate monohydrate in acetic acid containing 2% water is described, and a mechanism is proposed. The protocol has proved to be suitable for the monohydration of dicyanobenzenes and 2-substituted malononitriles.
Subject(s)
Acrylamides/chemistry , Copper/chemistry , Nitriles/chemistry , Organometallic Compounds/chemistry , Catalysis , Molecular Structure , StereoisomerismABSTRACT
A facile and efficient synthesis of substituted indeno[2,1-c]quinolin-6(7H)-ones from a variety of α-acyl N-arylcinnamamides mediated by polyphosphoric acid (PPA) is described, and a mechanism involving the formation of a dicationic superelectrophile and subsequent double intramolecular nucleophilic cyclization reactions is proposed.
Subject(s)
Heterocyclic Compounds, 4 or More Rings/chemical synthesis , Indenes/chemical synthesis , Phosphoric Acids/chemistry , Polymers/chemistry , Quinolones/chemical synthesis , Catalysis , Cyclization , Heterocyclic Compounds, 4 or More Rings/chemistry , Indenes/chemistry , Molecular Structure , Quinolones/chemistry , StereoisomerismABSTRACT
A facile and efficient synthesis of substituted quinolin-2(1H)-ones is developed via intramolecular cyclization of penta-2,4-dienamides mediated by concentrated H(2)SO(4) (98%), and a mechanism involving the formation of a dicationic superelectrophile, and subsequent intramolecular nucleophilic cyclization reactions is proposed.
