A novel route to 2,3-pyrazol-1(5H)-ones via palladium-catalyzed carbonylation of 1,2-diaza-1,3-butadienes.
[reaction--see text] A novel Pd(0)-catalyzed carbonylation of both isolable 1,2-diaza-1,3-butadienes and those generated in situ by extrusion of SO(2) and CO(2) from heterocyclic precursors is described. The reaction proceeds at room temperature to 110 degrees C under 1-2 atm of CO to afford 2,3-pyrazol-1(5H)-ones in good to excellent yields. The effect of catalyst structure and stability on the carbonylation reaction is evaluated.
Boeckman
R K
RK
Department of Chemistry, University of Rochester, Rochester, New York 14627-0216, USA. rkb@rkbmac.chem.rochester.edu
Reed
J E
JE
Ge
P
P
D000475:Alkenes / Q000737:chemistry*; D001372:Aza Compounds / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D007202:Indicators and Reagents; D010165:Palladium; D011720:Pyrazoles / Q000138:chemical synthesis*
D000475:Alkenes; D001372:Aza Compounds; D007202:Indicators and Reagents; D011720:Pyrazoles; D010165:Palladium