Asymmetric hydrovinylation of styrene applying cationic allyl palladium complexes of a P-chiral ligand

Synthesis and characterization of palladium(II) complexes with chiral aminophosphine ligands: Catalytic behaviour in asymmetric hydrovinylation. Crystal structure of cis-[PdCl2(PPh((R)-NHCHCH3Ph)2)2]

“…Both TOF values are depicted in Table 6 when data are available. The best catalytic properties for the formation of 3-phenyl-1-butene is observed with the mixed complex [Pd(g 3 -2-CH 3 C 3 H 4 )(NCCH 3 )PBn 3 ]BF 4 (4g) (entries 15 vs. 1, 4,7,14,17). This fact suggests that the steric bulk and electronic properties in PBn 3 ligand allow a good stabilization of hydride active species and a fast reaction, as described for nickel complexes [39].…”

“…Very good enantioselectivities were initially obtained by Wilke [3] and more recently by the groups of Vogt [4], Gibson [5], Rajanbabu [6,7], Leitner [8] and Zhou [9] using phosphines, planar chromium phosphines, phosphinites, or phosphoramidites as stabilizing ligands with nickel and palladium systems. We investigated the model reaction using nickel and palladium precursors.…”

P-Stereogenic monophosphines in Pd-catalysed enantioselective hydrovinylation of styrene

“…To circumvent this difficulty, several approaches such as pure steric shielding [1,23,24] or the dendritic effect [25e27] have been applied but the most successful has been the use of ligands possessing pendant groups capable of interacting with and stabilising the metal centre [28,29]. This strategy has been intensively pursued by RajanBabu [1,22,30e33], Leitner [34e37] and Zhou [8,38] employing Ni systems.…”

“…Our group [24,26,27,39e41] and others [23] have been studying the hydrovinylation reaction using palladium p-allylic complexes with several types of monodentate P-stereogenic ligands as precatalysts. This is an interesting class of ligands to be explored in hydrovinylation since the close proximity of the stereogenic phosphorus to the metallic centre can provide high enantioselectivities as shown by Vogt and coworkers [23] and by us [24,26,27].…”

Application of P-Stereogenic Aminophosphine Phosphinite Ligands in Asymmetric Hydroformylation

“…In order to accomplish this, it should be helpful to bring the center of chirality as close to the metal as possible. After our success with P-chiral ligands in the asymmetric hydrovinylation reaction, [6] we decided to design new P-chiral chelating ligands for use in asymmetric hydroformylation.…”