Zinc-catalyzed synthesis of pyrazolines and pyrazoles via hydrohydrazination.
A novel regioselective synthesis of aryl-substituted pyrazolines and pyrazoles has been developed. Substituted phenylhydrazines react with 3-butynol in the presence of a catalytic amount of zinc triflate to give pyrazoline derivatives. The resulting products are easily oxidized in a one-pot procedure to the corresponding pyrazoles.
Alex
Karolin
K
Leibniz-Institut für Katalyse eV, Universität Rostock, Rostock, Germany.
Tillack
Annegret
A
Schwarz
Nicolle
N
Beller
Matthias
M
D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D006834:Hydrazines / Q000737:chemistry*; D015394:Molecular Structure; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D015032:Zinc / Q000737:chemistry*
D006834:Hydrazines; D011720:Pyrazoles; D015032:Zinc