SYNTHESIS AND RESOLUTION OF QUINAZOLINONE ATROPISOMERIC PHOSPHINE-LIGANDS

The syntheses of [2'-(diphenylphosphino)phenyl]-4(3H)-quinazolinone (M PQ, 1a) and methyl-substituted analogues were achieved in good yield b y coupling N-acetylanthranilic acid with the corresponding phosphinoan ilines. Resolution of ligand 1b was achieved using (-)-di-mu-chlorobis [(S)-dimethyl-( 1-phenylethyl)aminato-C-2,N]dipalladium(II) (5). The r esulting crystalline complex (S,R)-6 served to unambiguously assign th e absolute configuration of antipode (R)-(-)-1b. A practical resolutio n of this series of ligands 1a-c was accomplished using the (benzenesu lfonyl)hydrazone derivative of camphorsulfonic acid (7) as a resolving agent.