Phosphororganische verbindungen optisch aktive tertiäre phosphine aus optisch aktiven quartären phosphoniumsalzen

Rhodium

“…Following Wilkinson's discovery of [RhCl(PPh 3 ) 3 ] as an homogeneous hydrogenation catalyst for unhindered alkenes [ 14 b, 35], and the development of methods to prepare chiral phosphines by Mislow [36] and Horner [37], Knowles [38] and Horner [15,39] each showed that, with the use of optically active tertiary phosphines as ligands in complexes of rhodium, the enantioselective asymmetric hydrogenation of prochiral C=C double bonds is possible (Scheme 1.8).…”

Synthesis, Derivatisation and Structural Characterisation of a New Macrobicyclic Phosphane Oxide Cryptand

“…Due to a high tendency for oxidation during workup and purification, we reoxidised the crude phosphane with H 2 O 2 with retention (Scheme 3). [15][16][17][18] Thus, we could investigate the stereochemical outcome of the reductive step by making use of the phosphane oxide product distribution. To our surprise, after this reduction/oxidation procedure we exclusively obtained a single product which turned out to be identical with the starting phosphane oxide 6 (Scheme 3).…”

Homo‐ and Cross‐Olefin Metathesis Coupling of Vinylphosphane Oxides and Electron‐Poor Alkenes: Access to P‐Stereogenic Dienophiles

“…[28] In contrast to most amines, phosphanes can show configurational stability. [29] As in complexes of P-stereogenic phosphane ligands the chiral information is located much closer to the metal atom than in complexes of phosphane ligands bearing the chiral information in the molecular backbone, asymmetric reactions taking place at the metal atom usually proceed with a high degree of enantioselectivity. [30] Imamoto et al have investigated this field using P-stereogenic phosphane-boranes as ligand precursors and found exceptionally high enantiomeric excesses in rhodium-catalyzed hydrogenation reactions.…”