A ruthenium-catalyzedswitchableN–H/C–Halkenylation reaction of 6-phenyl-(dihydro)pyridazin-3(2H)-ones triggered by a nitrogen/oxygen atmosphere was developed. To achieve switchable modification of the two important sites of the widely used pharmacophore, a simple and efficient procedure containing two optimized ruthenium catalytic systems was utilized, which afforded excellent activity, high selectivity
A Cu-catalyzed tandem dehydrogenation/dehalogenation sequential reaction along with N-arylation has been developed for the synthesis of pyridazinone derivatives in an aerobic and aqueous environment. To achieve the transformation of three chemical bonds in a one-pot reaction, a multifunctional copper catalyst was used which afforded excellent activity, high selectivity, and recyclability. The catalytic system consists of a water-soluble Cusalen complex and Na2CO3 in neat water and an air atmosphere.
ALBRIGHT J. D.; MCEVOY F. J.; MORAN D. B., J. HETEROCYCL. CHEM., 1978, 15, NO 6, 881-892