Asymmetric Synthesis And Bioactivities Of2-alkyl-3-phosphonopropanoic Acid Derivatives

Asymmetric catalysis is one of the most effective ways to obtain chiral compounds. chiral ligands provide chiral source for chiral catalyst. Among lots of chiral liands, ferrocene-based ligands become one of the most widely used ligands in asymmetric catalysis for their unique traits.In this papr,2-phosphonomethyl-3-arylpropenoates were prepared via a two-step transformation from aromatic aldehydes.Commercially available ferrocene-based diphosphine ligand, TaniaPhos, was found to be highly effective in the Rh-catalyzed asymmetric hydrogenation of a challenging substrate class,2-phosphonomethyl-3-arylpropenates. Excellent enantioselectivity (90-98%ee) and high catalytic activity (S/C up to1000) have been achieved, which represents the best results reported so far. Results suggested that the ester functional group of2-phosphonomethyl-3-arylpropenoates had a significant influence on the reactivity and enantioselectivity, and the substrate with the less sterically hindered ester functional group was favorable for this hydrogenation. The hydrogenation was also sensitive to the solvent used. CH2Cl2was optimal solvent. The pressure of H2had less influence on the reactivity and enantioselectivity at a catalyst loading of1mol%. The hydrogenation of the substrates with a heteroaromatic substituent also led to good enantioselectivities.The preliminary bioassay screening showed that some of the racemic compounds exhibited certain bioactivities. The inhibiting activity of (±) P3、(±) P5and (±) P6on Pyricularia grisea were12.13%、23.37%and67.66%at600μg/ml; the mortality of (±) P8、(±) P10、(±) P11and (±)P14against Prodenia litura (Fabricius) were23%,30%,13%and40%; but unfortunately, there were no exciting activities which we expected were observed in the weeding tests under tested concentrations.