Pn ligand

To date, the most popular and successful designs for PN-ligands have incorporated an achiral phosphine with a substituted non-aromatic heterocyde as the primary chiral unit, largely due to the ease by which the P and N modules may be altered, and the ready availability of enantiopure, amino add-derived starting materials.1281 Considerable variation of the predse steric and electronic environment imposed on a chelated metal centre has been achieved by the synthesis of a substantial library of... 

O. Loiseleur, M. Hayashi, M. Keenan, N. Schmees, A. Pfaltz, Enantioselective Heck Reactions using Chiral PN-Ligands, J. Organomet. Chem. 1999, 576,16-22. 

Tetragonal co-ordination with 2 chelating pn ligands and S-bonded NCS groups Centrosymmetric dimer. Each Cu surrounded by 7 atoms. Asymmetric bidentate NO 3 co-ordination Both have exactly trans planar co-ordination... 

That the PN ligands in Co2(CO)b(PN)2, which can also be obtained from Co2(CO)4(nor-C7H8)2 (nor-C7Hg = norbornadiene) and PN via elimination of metallic cobalt, are monodentate is readily shown by N-meth-ylation with Mel to give the [Co.j(CO)d(Ph2P—CHaCHa—Et2Me)2]2+ cation (183). 

With the bidentate o-(diphenylphosphino)benzaldehyde (PO) and o-[(diphenylphosphino)benzylidene]aniline (PN) ligands the complexes [ReX(CO)3(PO)] (X is halide, 94) and [ReX(CO)3(PN)] (X is halide, 95) have been synthesized and characterized, starting from [ReX(CO)5] (X is Br, Cl) [92]. Using the same starting material, complexes of the type/ac-[Re(CO)3(K 3-L) (96) were also prepared, where L is a phosphorus-containing heterotridentate ligand, obtained by condensation of 2-(diphenylphosphino)aniline with several salicylaldehyde derivatives (Scheme 24) [93]. 

CnCiim] [various] [C4ClPy][Tf2N] [IrCl(cod)]2 + PN-ligand Imines 30-100 bar, 0-40°C scC02 as co-solvent product extracted with scC02. [11]... 

In allylic substitution and presumably in other reactions (vide supra), MAP acts as an RCjpso-ligand rather than PN-ligand, as evidenced by NMR and X-ray crystallography (eq 6). Strong memory effects, observed in the case of allylic substitution of cyclic substrates, are associated with this unusual coordination. ... 

Ein pn-Ligand ist mit n Metallatomen verbunden. Liegt eine Ti"-Bindung (sprich hapto n) vor, so koordinieren n Ligandenatome ein oder mehrere Metallatome. 

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