Asymmetric transfer hydrogenation of various simple aromatic ketones by the Ru-TsDPEN catalyst was shown to be feasible in aqueous HCOONa without calling for any modification, furnishing ee's up 95% and significantly faster rates than HCOOH–NEt3 azeotrope.

PhanePhos-ruthenium-diamine complexes catalyze the asymmetric hydrogenation of a wide range aromatic, heteroaromatic, and alpha, beta-unsaturated ketones with high activity excellent enantioselectivity.

[(Bisphosphine) RuCl 2 (1,2-diamine)] complexes are powerful catalysts in the asymmetric hydrogenation of unfunctionalized ketones. We sought to expand scope and applicability these by exploring changes diamine structural motif. Via introduction 1,3- 1,4-diamines, catalytic activity was significantly altered such that new classes ketones could be considered for [(bisphosphine) (diamine)] hydrogenation.

This paper reports the synthesis of highly cross-linked polymers in supercritical CO2 (scCO2), both with and without addition a CO2-soluble diblock copolymer stabilizer. It was demonstrated that, under certain specific conditions, relatively uniform, nonporous poly(divinylbenzene) (PDVB) microspheres (1−5 μm diameter) can be generated absence added stabilizers. The effects cross-linker ratio, monomer concentration, structure, mechanical agitation were investigated. A stabilizer synthesized...

Conformationally restricted amino alcohols based on carbohydrate scaffolds provide flexible and fine-tuneable libraries that greatly expand the range of ligands available in Zn(OTf)2-mediated addition alkynes to aldehydes, some cases with very high stereoselectivities.

A highly enantioselective and cost efficient process for the synthesis of (+)-erythro mefloquine has been developed. The key step is an reduction pyridyl ketone KI using transfer hydrogenation with formic acid as hydrogen source. ratio to NEt3 was found be very important achieving a process.

[reaction: see text] A poly(ethylene glycol)-supported chiral diamine (PEG-2), in which the polymer is attached to phenyl rings, has been synthesized and shown be highly effective asymmetric hydrogenation of unfunctionalized aromatic ketones with possibility reuse. PEG-2 can also serve as a scaffold on various immobilized catalysts could easily built.

The asymmetric reduction of carbonyl, C=O, groups for the production enantiomerically pure secondary alcohols is a reaction fundamental importance in modern synthetic chemistry. This can be performed number ways. Asymmetric chemocatalysis (1) and often complementary biocatalysis offer solutions to stereoselective C=O groups. These two techniques have found wide industrial application (2). In mid 1990s, new ruthenium systems based on dihydrogen or transfer hydrogenation prochiral ketones were...

Rh diphosphine complexes using DuPhos and JosiPhos as chiral ligands have been immobilised by ion exchange into the mesoporous material MCM-41. When used catalysts for enantioselective hydrogenation of dimethyl itaconate methyl-2-acetamidoacrylate, these heterogeneous give catalytic performance in terms yield enantioselection that are comparable to corresponding homogeneous catalysts. Furthermore, can be readily recovered reused without loss catalyst performance. A second immobilisation...

The regioselective functionalization of 4,12-dibromoparacyclophane via electrophilic aromatic substitution is reported for the first time. paracyclophane backbone allows development a new family paracyclophane-based phosphines (named ParaPhos) that opens possibility improved catalyst and tuning while retaining all catalysis potential PhanePhos ligands.

The use of three chiral 1,4-diamines in the [(diphosphine) RuCl2 (diamine)] catalyst system is demonstrated hydrogenation acetophenone. a 1,4-diamine offers unique properties that allow tuning system. These include first example racemic diamine combination with phosphine, which gives 95% ee isobutyrophenone

Application of the 'screened anionic polymerisation' method to synthesis well-defined AB block copolymers derived from methyl methacrylate and fluorinated monomers has provided a family tuneable surfactants for free radical dispersion polymerisation in supercritical carbon dioxide. Poly(methyl methacrylate) is obtained with excellent conversion high molecular weight. Block having higher weight fluorine contents are superior surfactants, by systematic evaluation parameters methacrylate,...

Screened anionic copolymerisation of methyl methacrylate with the perfluoroalkyl methacrylates 2 affords well-defined AB block copolymers 4–6, which serve as effective surfactants in dispersion polymerisation supercritical carbon dioxide.

Die nützliche Kombination von hoher katalytischer Aktivität und Enantioselektivität bieten Rhodiumkatalysatoren mit FerroTANE-Liganden bei der Hydrierung Itaconsäurederivaten (siehe Schema). Reaktionen, durchgeführt einem Substrat-Katalysator-Verhältnis 20 000, sind nach 3 h beendet liefern 2-Alkylbernsteinsäuremonoamide bis zu 99 % ee.

The ready construction of 24 stereochemically and functionally diverse carbohydrate ligand structures from a core D-glucosamine scaffold has allowed the evaluation broad ranging structure activity relationships in accelerated zincate additions to aldehydes, with variations ΔΔG‡(R-S) up 5650 J mol−1 that create opposing senses asymmetric induction are consistent models based on several X-ray molecular mechanics analysis. Factorial analysis enantioselectivity using key dihedral angles steric...

An improved method has been developed for the efficient synthesis of stable camphor imine salts. Camphor readily undergoes transimination with α-amino acid ester hydrochlorides to yield camphorylidene amino derivatives E stereochemistry about CN double bond. Sodium cyanoborohydride reduction derived ketimines gives exo-bornylamines.

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