Catalytic Enantioselective Synthesis of N-C Axially Chiral Sulfonamides through Chiral Palladium-Catalyzed N-Allylation.

In the presence of ( S,S)-Trost ligand and (allyl-Pd-Cl)2 catalyst, the reaction of allyl acetate with the anionic species prepared from various N-(2- tert-butylphenyl)sulfonamides and NaH proceeded in an enantioselective manner (up to 95% ee) to give optically active N-allylated sulfonamide derivatives possessing an N-C axially chiral structure in high yields.

N-C Axially Chiral Compounds with an ortho-Fluoro Substituent and Steric Discrimination between Hydrogen and Fluorine Atoms Based on a Diastereoselective Model Reaction.

The fluorine atom is the second smallest atom; nevertheless, the ortho-fluoro group may lead to stable N-aryl atropisomers when the steric demand of the flanking substituents is large enough. 2-Alkyl-3-(2-fluorophenyl)quinazolin-4-ones and 3-(2-fluorophenyl)-4-methylthiazoline-2-thione were found to be the first N-aryl axially chiral compounds bearing an ortho-fluoro group whose enantiomers were isolated at ambient temperature. The reaction of alkyl halides with the anionic species prepared from 2-ethyl-3-(2-fluorophenyl)quinazolin-4-one presenting an N-C axial chirality provided a model reaction for quantitative evaluation of the steric discrimination (slight difference of steric factor) between hydrogen and fluorine atoms. In the case of low steric demand (allylation reaction) no diastereoselectivity was detected, while in the case of high steric demand (isopropylation reaction) the diastereoselectivity became significant.

Diastereoselective α-Alkylation of Metallo Enamines Generated from N-C Axially Chiral Mebroqualone Derivatives.

The reactions of various alkyl halides with the metallo enamines generated from racemic and optically pure N-C axially chiral mebroqualone derivatives were found to proceed with a synthetically attractive stereochemical outcome (up to 99% yield and up to dr = 26:1) allowing preparation of a structurally new type of pharmaceutically interesting compounds possessing elements of axial and central chirality.

Temperature-dependent photocatalytic hydrogen evolution activity from water on a dye-sensitized layered titanate.

Visible light-induced hydrogen evolution activity from water on a ruthenium complex-sensitized layered titanate was modified when the reaction was conducted at higher temperature.

Efficient visible-light-induced photocatalytic activity on gold-nanoparticle-supported layered titanate.

The visible-light-induced photocatalytic conversion of aqueous benzene to phenol on Au-nanoparticle-supported layered titanate was accelerated when the reaction was conducted in the presence of aqueous phenol.