Asymmetric allylation of unsymmetrical 1,3-diketones using a BINAP-palladium catalyst
(Matrix presented) The chiral palladium complex generated in situ from [Pd(η3-allyl)Cl]2 and (R)-BINAP is a good catalyst for the catalytic asymmetric allylation of 1,3-diketones. The reaction provided chiral 2,2-dialkyl-1,3-diketones with 64-89% ee in high yields (13 examples). Enantiomeric excesses are strongly affected by the γ-substituent of the allylic substrates. A variety of unsymmetrical 1,3-diketones were alkylated with cinnamyl acetate in good enantioselectivities via use of the BINAP-palladium catalyst (77-89% ee).
Kuwano, Ryoichi,Uchida, Kei-Ichi,Ito, Yoshihiko
p. 2177 - 2179
(2007/10/03)
Chiral phosphine ligands modified by crown ethers: An application to palladium-catalyzed asymmetric allylation of β-diketones
Chiral ferrocenylphosphine ligands modified by monoaza or diaza crown ethers of varying ring sizes and linker chain lengths (8a-e, 9) were synthesized. The reaction of the phosphine ligand modified by monoaza-18-crown-6 (8b) and the di-μ-chlorobis(T-allyl
Asymmetric Synthesis Catalyzed by Chiral Ferrocenylphosphine-Transition-Metal Complexes. 5. Palladium-Catalyzed Asymmetric Allylation of Active Methine Compounds
Catalytic asymmetric allylation of sodium enolates of β-diketones with allyl acetate proceeded with high enantioselectivity in the presence of 0.5-1.0 mol percent of palladium complexes as catalysts bearing functionalized chiral ferrocenylphosphine ligand