The synthesis of phosphine oxide-linked bis(oxazoline) ligands and their application in asymmetric allylic alkylation
作者:Yu Jin、Da-Ming Du
DOI:10.1016/j.tet.2012.02.078
日期:2012.5
The phosphine oxide-linked bis(oxazoline) ligands were designed and synthesized in two ways. One is the coupling of Grignard reagent derived from 2-(2-bromophenyl)oxazoline with phenylphosphonic dichloride, another route is the condensation of bis(2-formylphenyl)(phenyl)phosphine oxide with chiral amino alcohols followed by NBS oxidation. These new bis(oxazoline) ligands were applied in Pd-catalyzed
New Schiff bases derived from chiral d‐camphor were determined to be effective phosphine ligands for the asymmetric palladium‐catalyzed allylic alkylation of activated methylene compounds, the allylic etherification of alcohols, and the allylic amination of primary amines or secondary amines, in which the corresponding products with various functional groups were achieved in good yields with excellent
Chiral Imidazoline–Phosphine Ligands for Palladium-Catalyzed Asymmetric Allylic Substitutions
作者:Liang-yong Mei、Zhi-liang Yuan、Min Shi
DOI:10.1021/om2008309
日期:2011.12.12
to 96% ee), and chiral ligand L9 can be used for the palladium-catalyzedasymmetric allylic monofluoromethylation of 1,3-diphenylpropenyl acetate with 1-fluorobis(phenylsulfonyl)methane to afford the corresponding product in excellent enantioselectivities (up to 98% ee) and moderate yields under mild conditions. The bidentate N,P-coordination pattern to the Pd atom with ligand L1 has been unambiguously
Practical Pd/C-Mediated Allylic Substitution in Water
作者:François-Xavier Felpin、Yannick Landais
DOI:10.1021/jo050952t
日期:2005.8.1
Pd/C-mediated allylic substitution in water is described as an interesting alternative to classical homogeneous conditions. The reaction applied to allylic acetates showed a wide range of compatibility with various nitrogen, sulfur, oxygen, and carbon nucleophiles. Notably, the method features inexpensive reagents and a nontoxic solvent. Moreover, measurement of the palladium content in water by ICP-MS
Palladium-catalyzedasymmetricallylic alkylation of 1,3-diphenyl-2-propenyl acetate (8a) with a dimethyl malonate–BSA–LiOAc system has been successfully carried out in the presence of novel chiral phosphine–oxazinane ligands such as 5b in good yields with good enantioselectivities (up to 95% ee).