14678-97-8Relevant academic research and scientific papers
Copper(I)/Copper(II)-Assisted Tandem Catalysis: The Case Study of Ullmann/Chan-Evans-Lam N1,N3-Diarylation of 3-Aminopyrazole
Beyer, Astrid,Castanheiro, Thomas,Busca, Patricia,Prestat, Guillaume
, p. 2433 - 2436 (2015/08/24)
Unprecedented CuI/CuII-assisted tandem catalysis allowing an Ullmann/Chan-Evans-Lam sequence was achieved. This three-component, one-pot reaction triggered by a change in the oxidation state of the metal leads to the selective N1,N3-diarylation of 3-aminopyrazole. This new method should be a valuable tool for small-molecule drug discovery that requires suitable regio- and/or chemoselective strategies for the N-arylation of nitrogen-containing heterocycles. Tandem power: The first assisted tandem copper-catalyzed process, triggered by a change in the oxidation state of the metal, is developed to allow a one-pot Ullman/Chan-Evans-Lam sequence leading to the selective N1,N3-diarylation of 3-aminopyrazole.
VILSMEIER-HAACK REACTION OF 5-AMINO- AND 5-ACYLAMINO-PYRAZOLES
Simay, A.,Takacs, K.,Horvath, K.,Dvortsak, P.
, p. 127 - 140 (2007/10/02)
The Vilsmeier-Haack reaction of 5-aminopyrazole derivatives 1 was investigated in view of contradictory literature reports.Structure 2 of the products was proved both chemically and spectroscopically.The mechanism of the reaction was postulated on the basis of isolated intermediates 7 and 8. 5-Acylaminopyrazoles 9, 10 and 11 were found to give also 2 (and 7) under the Vilsmeier conditions by an acyl splitting reaction, proceeding probably via diacylamino derivatives 12.Compounds 2 provided a simple route to pyrazolopyrimidine derivatives 13 and 14 as well as to azomethine compounds 15-18.
