Ruthenium-Catalyzed Direct Asymmetric Reductive Amination of Diaryl and Sterically Hindered Ketones with Ammonium Salts and H2

A Ru-catalyzed direct asymmetric reductive amination of ortho-OH-substituted diaryl and sterically hindered ketones with ammonium salts is reported. This method represents a straightforward route toward the synthesis of synthetically useful chiral primary diarylmethylamines and sterically hindered benzylamines (up to 97 % yield, 93–>99 % ee). Elaborations of the chiral amine products into bioactive compounds and a chiral ligand were demonstrated through manipulation of the removable and convertible -OH group.     

One-pot synthesis of diaryl ketones from aldehydes via palladium-catalyzed reaction with aryl boronic acids

A Pd-catalyzed coupling-type reaction of aldehydes and organoboronic acids was achieved in the presence of P(1-nap)₃, using Cs₂CO₃ in toluene, providing diaryl ketones with yields ranged from moderate to excellent. The efficiency of this reaction was demonstrated by the compatibility with nitro, cyano, trifluoromethyl, fluoro and chloro groups. Moreover, the rigorous exclusion of air/moisture is not required in these transformations.     

Cesium hydroxide-promoted aerobic oxidation of sec-aromatic alcohols

A CsOH-promoted aerobic oxidation of sec-aromatic alcohols has been developed, using air as a free and clean oxidant, and providing aryl ketones in good to excellent yields.     

Asymmetric Epoxidation of Methyl Gibberellate by the Modified Sharpless Reagent

Asymmetric epoxidation of methyl gibberellate by the modified Sharpless reagent in the various temperature is described. Compound 8 and 9 can be used as the key intermediates for synthesis of the polyhydroxygibberellins.