trifluoromethylated organic compounds, especially chiral quaternary alcohols bearing trifluoromethyl group are of important intermediates in drugs, agrochemicals and etc.an efficient epoxidation of β-cf3-β,β-disubstituted unsaturated ketones (6) has been developed with environmental benign hydrogen peroxide as the oxidant and f5-substituted chiral quaternary ammonium salt (1g or 5) derived from...

The preparation of a range of asymmetric iron and ruthenium-cyclone complexes, and their application to the asymmetric reduction of a ketone, are described. The enantioselectivity of ketone reduction is influenced by a single chiral centre in the catalyst, as well as by the planar chirality in the catalyst. This represents the first example of asymmetric ketone reduction using an iron cyclone c...

A new catalyst is designed, synthesized, and evaluated for the asymmetric Michael addition of nitroalkanes to nitroalkenes. The obdurate nature of this reaction has made this a formidable challenge to subdue by asymmetric catalysis. The catalyst design includes a thiourea function to activate the nitroalkene by a double H-bond and a 4-dimethylaminopyridine unit to deprotonate the nitroalkane an...

The asymmetric transfer hydrogenation of imines was performed with the use of a polymer-immobilized chiral catalyst. The chiral catalyst, prepared from crosslinked polystyrene-immobilized chiral 1,2-diamine monosulfonamide, was effective in the asymmetric transfer hydrogenation of N-benzyl imines in CH(2)Cl(2) to give a chiral amine in high yield and good enantioselectivity. Furthermore, an amp...

Complementary to enantioselective transformations of planar functionalities, catalytic desymmetrization of meso compounds is another fundamentally important strategy for asymmetric synthesis. However, experimentally established stereochemical models on how a chiral catalyst discriminates between two enantiotopic functional groups in the desymmetrization of a meso substrate are particularly lack...

Asymmetric catalysis in flow has been attracting much attention very recently because of the potential advantages over its batchwise counterpart, such as highthroughput screening and synthesis, easy automation with the integration of on-demand reaction analysis, little or no reaction workup, and potential long-term use of the catalysts in the case of heterogeneous catalysis. Homogeneous asymmet...

A combinatorial in situ three-component chiral oxazoline-Schiff base copper(II) complex catalyst formation method was developed. This simple combinatorial chiral catalyst approach provided a modular library of chiral oxazoline-Schiff base copper(II) complex catalysts. The catalytic activity of these in situ generated catalysts can be rapidly and conveniently evaluated in the asymmetric Henry re...

Large asymmetric amplification originating from solubility differences between the enantiopure and the racemic catalyst is observed in the addition of Grignard reagents to enones. This behaviour is not reaction or catalyst specific and is observed for metal complexes of a variety of chiral diphosphine ligands, extensively used in asymmetric catalysis.

An air-stable catalyst system Ir-(P-Phos) catalyst was found to be highly effective in the asymmetric hydrogenation of quinoline derivatives. The catalyst immobilized in DMPEG was efficiently recovered and reused eight times, retaining reactivity and enantioselectivity.

TiCl4/nano-cellulose as a biodegradable and eco-friendly Lewis acid catalyst was synthesized via reaction of nano-cellulose and TiCl4. This catalyst was characterized and used for synthesis of asymmetric highly functionalized tetrahydropyridines via a five-component condensation reaction of p-substituted anilines, aldehydes and ethyl acetoacetate under solvent-free condition. Simple methodology...