STRUCTURAL CHEMISTRY OF CHIRAL COMPLEXES - NMR AND X-RAY STUDIES ON RH1 COMPOUNDS OF (S)-1-[BIS(P-METHYLPHENYL)PHOSPHINO]-2-[(P-METHOXYBENZYL)AMINO]-3-METHYLBUTANE

The Rh(I)(diolefin)complexes [Rh(nbd)(2)][PF6] [Rh(1,5-cod)(2)][PF6], and [Rh((Z)-alpha-acetamidocinnamic acid)(2)][PF6] (2=the chiral P,N-ligand (S)-1-[bis(p-methylphenyl)phospino]-2-[(p-methoxybenzyl)amino]-3-methylbutane) have been prepared and characterized. These complexes exist as a mixture of isomers arising from different five-membered-ring conformations and diastereoisomers due to both the prochiral nitrogen and olefin ligands. The three-dimensional solution structures of these complexes have been studied with the specific aim of understanding how the chiral pocket is built. Aspects of the exchange dynamics and their possible relevance to homogeneous hydrogenation are discussed. The solid-state structure for the nbd complex, [Rh(nbd)(2)][PF6], as well as detailed one- and two-dimensional P-31-, C-13-, and H-1-NMR results are presented.