Synthesis and Resolution of Quinazolinone Atropisomeric Phosphine Ligands<sup>,</sup>
作者:Xuedong Dai、Audrey Wong、Scott C. Virgil
DOI:10.1021/jo972105z
日期:1998.4.1
The syntheses of 2-methyl-3-[2'-(diphenylphosphino)phenyl]-4(3H)-quinazolinone (MPQ, 1a) and methyl-substituted analogues were achieved in good yield by coupling N-acetylanthranilic acid with the corresponding phosphinoanilines. Resolution of ligand 1b was achieved using (-)-di-mu-chlorobis[(S)-dimethyl-( 1-phenylethyl)aminato-C-2,N]dipalladium(II) (5). The resulting crystalline complex (S,R)-6 served to unambiguously assign the absolute configuration of antipode (R)-(-)-1b. A practical resolution of this series of ligands 1a-c was accomplished using the (benzenesulfonyl)hydrazone derivative of camphorsulfonic acid (7) as a resolving agent.