Synthesis of benzo[c]-2,7-naphthyridines by palladium-catalyzed coupling of pyridine methylstannanes with ortho bromoacetanilides in the presence of copper(II)oxide

Unusual Reactivity of (Vinylimino)phosphoranes and Their Utility in the Preparation of Pyridine and Dihydropyridine Derivatives

“…Reduction of compound 18d with Fe/HOAc directly gave the benzo[ c ][2,7]naphthyridinone 19 in 74% yield. Some related derivatives of this ring system, which have been utilized as key intermediates in the synthesis of the marine alkaloid amphimedine, have been prepared recently by Pd-catalyzed Suzuki or Stille cross-coupling reaction followed by cyclization.…”

Palladium-Assisted Routes to Nucleosides

“…Ozola et al described several 8-(2-and 3-thienyl)-and 8-(2-and 3-furyl)-2,6-diaminopurine derivatives (142), the synthesis of which was accomplished through a Stille cross-coupling reaction between 2-and 3-tributylstannylthiophene or 2-and 3-tributylstannylfuran and the 8-bromopurine analogue 141 (Scheme 45). 123 The use of DMF 124 at 110 °C, and dichloro(diphenylphosphinepropane)palladium(II) (PdCl 2 (dppb)) with cupric oxide as cocatalyst, 125 was necessary to obtain optimal yields (80%).…”

Naphthyridines. Structure, physicochemical properties and general methods of synthesis

“…178 Cross-coupling of o-bromoacetanilides 205 with trimethylstannylpyridyl ketones 206 in the presence of PdCl 2 and CuO in DMF affords benzo[c]-2,7-naphthyridines 207. 185 Benzo[c]-2,7naphthyridines 208 were prepared by refluxing 2-tert-butoxycarbonylaminophenylboronic acid 209 with substituted iodonicotinaldehydes 210 in the presence of Pd(PPh 3 ) 4 and K 2 CO 3 in a mixture of ethanol and toluene. On treatment with concentrated hydrochloric acid at 100 8C, compound 214 undergoes disproportionation giving rise to a mixture of hexahydro (215) and dihydro derivatives of 1,8-naphthyridin-2-ones 216.…”