The enantioselective formation of a quaternary stereogenic center coinciding with a hydroxylation process is a very rare reaction from a homogeneous catalysis point of view. Indeed, to our knowledge, no asymmetric transition-metal-catalyzed direct hydroxylation has been reported before. We describe here our initial study concerning the enantioselective alpha-hydroxylation of various beta-ketoes...

Reaction of Ti(OiPr)(4) with various bis(β-diketones) and bis(β-ketoesters) (LH(2)) results in the formation of dimeric complexes [Ti(OiPr)(2)L](2), where each metal centre is coordinated by two terminal OiPr ligands and two bridging β-diketonate or β-ketoesterate groups (L). Macrocycles containing two M(OiPr)(2) moieties are thus formed. Reaction of Zr(OiPr)(4) with the same bis(β-diketones) a...

Lewis acidic indium(III) salts, in particular In(NTf(2))(3), effect the conversion of alpha-(omega'-alkynyl)-beta-ketoesters and omega-alkynyl-beta-ketoesters to the corresponding cyclic products in a manner known as the Conia-ene reaction. This reaction can lead to the creation of five- to fifteen-membered-ring carbocycles and heterocycles in good to excellent yields. The synthetic features of...

A series of 5-oxohexannitrile derivatives IIa-d was prepared by react ion of acry lonitrile with ketones Ia-d. On the other hand, semicarbazone derivatives IVa-d were obtained upon reaction of IIa-d with semicarbazide. Hydrolysis and esterification in one step reaction of δ-ketonitrile IIa-d resulted in the formation of the corresponding δ-ketoesters Va-d. The δ-ketoesters Va-d is readily cycli...

An aqueous solution of boric acid, as an efficient and green catalytic system, was efficiently utilized four-component cascade reaction of aryl aldehydes, dimedone, β-ketoesters and ammonium acetate to give hexahydroquinolines. By the reaction of boric acid with water, H+ was generated and efficiently catalyzed the reaction under mild and green condition. Also, optimization of the reaction cond...