Novel chiral 1,5-diaza-3,7-diphosphacyclooctane ligands and their transition metal complexes

Article abstract of DOI:10.1039/b300754e

Reaction of bis(hydroxymethyl)phenylphosphine with (R)- or (S)-α-methylbenzylamine leads to the novel cyclic chiral bisphosphine ligands 1,5-(R,R)- and 1,5-(S,S)-bis(α-methylbenzyl)-3,7-diphenyl-1,5- diaza-3,7-diphosphacyclooctane (1r or 1s). Novel chiral chelate complexes of Pt^II (2r, 3r and 3s), Pd^II (4s, 5s) and Re^I (6r) have been obtained by reaction of 1r or 1s with [MCl₂(cod)] (M = Pt, Pd; cod = 1,5-cyclooctadiene) and [{ReBr(CO)₃(thf )} ₂]. Compounds 1-6 were characterised by multinuclear NMR ( ¹H, ¹³C, ³¹P) and IR spcctroscopy. The former technique revealed the presence of two inequivalent phosphorus atoms in 6r. The molecular structure of 1r confirmed the absolute configuration of the chiral centers and a chair-chair conformation of the heterocycle with equatorial orientation of the substituents on phosphorus and axial on nitrogen atoms. Compound Is was used to form a palladium catalyst for the co-polymerisation of carbon monoxide and norbornadiene. The structures of the co-polymers obtained were characterised by GPC, ¹H and ¹³C NMR spectroscopy and elemental analysis. The Royal Society of Chemistry 2003.