P-Chirogenic Phosphine/Sulfide Hybrid Ligands

Abstract

P-Chirogenic phosphine/sulfide hybrid ligands 1 were prepared by the use of optically active phosphine-boranes as the intermediates. The palladium complexes of the ligands exhibited high catalytic activity and enantioselectivity in allylic alkylation of 1-acetoxy-1,3-diphenylprop-2-ene with malonate esters.

Recent developments on chiral P,S-type ligands and their applications in asymmetric catalysis

“…In 2001, Imamoto et al 57 designed a series of new P,S chiral ligands 48-49 bearing a chirogenic phosphorus atom as the only chiral element in the ligand. The effectiveness of these ligands was tested in Pd-catalyzed asymmetric allylic alkylation.…”

Electron-Rich Phosphines in Organic Synthesis II. Catalytic Applications

“…10 Such 'modular' syntheses have been exploited in the optimization of particular catalytic reactions. 11 Other recent examples of modular ligands include phosphinephosphites, 12 furanoside based phosphates, 13 and proline based P,N ligands, 14 both to make Pd catalysts for enantioselective reactions of allylic systems and phosphinethiophene 15 and phosphine-sulfide 16 hybrid ligands, again for enantioselective catalysis. A wide variety of P,N ligands (i.e.…”

[Bis(2-diphenylphosphinoethyl) sulfide-κ3P,S,P′](triphenylphosphine-κP)platinum(II) diperchlorate acetone solvate

“…A range of platinum metal complexes of phosphinothioether chelate ligands have been found to serve as ef®cient catalysts in homogeneous hydrogenation, carbonylation and asymmetric allylic alkylation reactions (Bayo  n et al, 1999;Dilworth et al, 1995;Sugama et al, 2001). In addition, the synthesis and characterization of Pt II complexes of mixed P,S-polydentate chelate ligands, which are acyclic or macrocyclic ligands, have attracted signi®cant attention (Andreasen et al, 1999;Connolly et al, 1997;Kyba et al, 1987;Siah et al, 1994).…”