2202-63-3Relevant academic research and scientific papers
Chiral (β-Aminoalkyl)phosphines. Highly Efficient Phosphine Ligands for Catalytic Asymmetric Grignard Cross-Coupling
Hayashi, Tamio,Konishi, Mitsuo,Fukushima, Motoo,Kanehira, Koichi,Hioki, Takeshi,Kumada, Makoto
, p. 2195 - 2202 (2007/10/02)
New chiral (β-aminoalkyl)phosphines, RCH(NMe2)CH2PPh2 , were prepared by starting with optically active amino acids.The phosphines were used as ligands for nickel-catalyzed asymmetric cross-coupling of 1-arylethyl Grignard reagents (ArMeCHMgCl) with vinyl bromide.Coupling products of over 70percent enantiomeric excess (ee) were obtained in the reaction with the ligand Phephos, Valphos, Ilephos, PhGlyphos, ChGlyphos, or t-Leuphos.A mechanism involving complexation of the magnesium atom in the Grignard reagent with the amino group on the (β-aminoalkyl)phosphine ligand is proposed to account for the high stereoselectivity.The asymmetric cross-coupling was applied to the synthesis of optically active 2-arylpropionic acids.
Chiral β-dimethylaminoalkylphosphines. Highly efficient ligands for a nickel complex catalyzed asymmetric grignard cross-coupling reaction
Hayashi, Tamio,Fukushima, Motoo,Konishi, Mitsuo,Kumada, Makoto
, p. 79 - 82 (2007/10/02)
Chiral β-dimethylaminoalkylphosphines were prepared starting with amino acids, (S)-alanine, (S)-phenylalanine, (R)-phenylglycine, (S)-valine, and (R)-tert-leucine. The chiral phosphines were found to be highly efficient ligands for a nickel catalyzed asymmetric Grignard cross-coupling reaction (38～94% optical yield).
