Synthesis and chemistry of a new P-N chelating ligand; (R) and (S)-6-(2′-diphenylphosphino-1′-naphthyl)phenanthridine
摘要:
A synthesis of the title phosphinamine (PHENAP) is described, following previously established methodology, Resolution via the C,N-palladocycle derived from (R)-N,N-dimethyl-alpha-methyl-1-naphthylamine led to two crystallographically defined complexes with the (R,S)-form posessing a chelated ligand and the (R,R)-form open with only the phosphine coordinated. Palladium allyl complexes of the ligand were strikingly different from those of the corresponding isoquinoline ligand QUINAP, and the differences could be rationalised by recourse to molecular models, with the additional fused arene ring of PHENAP playing a critical part in defining the coordination sphere through its steric pressure, A brief appraisal of Pd-catalysed allylic alkylation reactions was performed with the new ligand.