Enantioselective Reduction Of Aromatic Ketones Research Articles

ChemInform Abstract: Iron‐Catalyzed Highly Enantioselective Reduction of Aromatic Ketones with Chiral P2N4‐Type Macrocycles.

AbstractThe catalytic system in situ generated from the iron carbonyl complex and chiral 22‐membered tetraazadiphospha‐macrocycle PAC exhibits high activity and excellent enantioselectivity in the transfer hydrogenation of various aromatic ketones.

Iron‐Catalyzed Highly Enantioselective Reduction of Aromatic Ketones with Chiral P2N4‐Type Macrocycles

AbstractNovel P2N4‐donors containing chiral 22‐membered macrocyclic ligands have been synthesized and the structures have been determined by an X‐ray diffraction study. The catalytic systems in situ generated from triiron dodecarbonyl, Fe3(CO)12, and the chiral macrocyclic ligand exhibited high activity (TOF up to 1940 h−1) and excellent enantioselectivity with up to 99% ee in the asymmetric transfer hydrogenation of various aromatic ketones.

Synthesis of a new class of ligands derived from isosorbide and their application to asymmetric reduction of aromatic ketones by transfer hydrogenation

A new class of β-amino alcohol and diamine ligands has been prepared from isosorbide as a chiral renewable source. The efficiency of these ligands has been evaluated for the metal-catalyzed enantioselective reduction of aromatic ketones by transfer hydrogenation, giving excellent conversion and good enantioselectivity.

Syntheses of 1,2‐Amino Alcohols and Their Applications for Oxazaborolidine‐Catalyzed Enantioselective Reduction of Aromatic Ketones.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Syntheses of 1,2-Amino Alcohols and Their Applications for Oxazaborolidine Catalyzed Enantioselective Reduction of Aromatic Ketones

Six new chiral 1,2-amino alcohol derivatives have been synthesized starting from (1R,2R)-2-amino-1-phenylpropane-1,3-diol. Asymmetric reduction of aryl ketones with in-situ generated oxazaborolidine from these amino alcohol derivatives and BH3·Me2S afforded secondary alcohols with good yield and moderate to high enantiomeric excess.

New Efficient Organic Activators for Highly Enantioselective Reduction of Aromatic Ketones by Trichlorosilane.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

New Efficient Organic Activators for Highly Enantioselective Reduction of Aromatic Ketones by Trichlorosilane

[reaction: see text] Aryl ketones were reduced to the corresponding alcohols with excellent enantioselectivity (up to 99.7% ee) by Cl3SiH in the presence of a catalytic amount of N-formyl-alpha'-(2,4,6-triethylphenyl)-L-proline as an activator. Both carboxyl group at the alpha-position of the activator and 2,4,6-triethylphenyl group at the alpha'-position were critical for the high enantioselectivity.

Highly Catalytic Enantioselective Reduction of Aromatic Ketones Using Chiral Polymer‐Supported Corey, Bakshi, and Shibata Catalysts.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Highly catalytic enantioselective reduction of aromatic ketones using chiral polymer-supported Corey, Bakshi, and Shibata catalysts

A systematic study was conducted to formulate the optimal reaction parameters for polymer-supported (PS)-oxazaborolidine catalyzed enantioselective ketone reduction. The B-methylated chiral oxazaborolidine prepared in situ from the previously reported polymers by Degni et al. have been used in the enantioselective borane reduction of some substituted aromatic ketones to afford the corresponding optical active secondary alcohol products. While the linear-bound system shows low enantioselectivity, the cross-linked version affords enantioselectivities almost identical to those of the monomeric model (with up to 96% enantiomeric excesses).

A Simple Protocol for the One‐Pot Synthesis of Chiral Secondary Benzylic Alcohols by Catalytic Enantioselective Reduction of Aromatic Ketones.

A simple and efficient protocol for the one-pot catalytic enantioselective reduction of prochiral aromatic ketones mediated by in situ prepared catalysts derived from ( S)-(-)-diphenyl-pyrroli- din-2-yl-methanol, is reported.

A Simple Protocol for the One Pot Synthesis of Chiral Secondary Benzylic Alcohols by Catalytic Enantioselective Reduction of Aromatic Ketones

A simple and efficient protocol for the one-pot catalytic enantioselective reduction of prochiral aromatic ketones mediated by in situ prepared catalysts derived from (S)-(-)-diphenyl-pyrrolidin-2-yl-methanol, is reported.

Chiral amino-urea derivatives of (1 R,2 R)-1,2-diaminocyclohexane as ligands in the ruthenium catalysed asymmetric reduction of aromatic ketones by hydride transfer

Several new chiral urea and thiourea ligands have been prepared by reaction of (1 R,2 R)-1,2-diaminocyclohexane with various organic isocyanates and isothiocyanates. These were used as ligands in the ruthenium catalysed enantioselective reduction of aromatic ketones by isopropanol. The reduction proceeded at room temperature using 2 mol% of ruthenium catalyst to give good yields of the ( R)-alcohol with enantiomeric excesses of up to 83%. By contrast, the use of bis-urea ligands gave much lower enantioselectivities. Amino-thiourea ligands led to the ( S)-alcohol with low enantiomeric excess.

ChemInform Abstract: Enantioselective Reduction of Aromatic Ketones Catalyzed by Chiral Ruthenium(II) Complexes.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Enantioselective reduction of aromatic ketones catalysed by chiral ruthenium(II) complexes

The catalytic enantioselective reduction of aromatic ketones in 2-propanol is carried out by using ruthenium(II) complexes prepared from [Ru( p-cymene)Cl 2] 2 and a variety of chiral diamines and β-aminoalcohols derived from α-amino acids. Good conversions (>99%) and enantioselectivities (=96%) are observed under mild reaction conditions.

Quantum chemical study on enantioselective reduction of aromatic ketones catalyzed by chiral cyclic sulfur-containing oxazaborolidines. Part 1. Structures and properties of catalysts

Quantum chemical study on enantioselective reduction of aromatic ketones catalyzed by chiral cyclic sulfur-containing oxazaborolidines. Part 1. Structures and properties of catalysts

Quantum chemical study on enantioselective reduction of aromatic ketones catalyzed by chiral cyclic sulfur-containing oxazaborolidines. Part 1. Structures and properties of catalysts

Quantum chemical study on enantioselective reduction of aromatic ketones catalyzed by chiral cyclic sulfur-containing oxazaborolidines. Part 1. Structures and properties of catalysts

Quantum chemical study on enantioselective reduction of aromatic ketones catalyzed by chiral cyclic sulfur-containing oxazaborolidines. Part 2. Structures of catalyst-borane-ketone adducts

The chiral cyclic sulfur-containing oxazaborolidine catalyst reacts with aromatic ketone in the presence of borane to form the catalyst–alkoxyborane adduct with a B-O-B-N four-membered ring. The ab initio molecular orbital method is employed to study the structures of the catalyst–alkoxyborane adduct. All the calculated systems are optimized completely by means of the Hartree–Fock method at 6-31g* basis sets. The B-O-B-N four-membered ring is stable, although there is strong tensile stress in the four-membered ring. The catalyst–alkoxyborane adduct exists in four stable structures. Among these structures, the largest energy difference is only about 4 kJ/mol. In the catalyst–alkoxyborane adduct, the B(2)N(3) bond in the catalyst is weakened greatly. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 78: 261–268, 2000

Quantum chemical study on enantioselective reduction of aromatic ketones catalyzed by chiral cyclic sulfur-containing oxazaborolidines. Part 3. Structures of catalyst-alkoxyborane adducts

The chiral cyclic sulfur-containing oxazaborolidine catalyst reacts with aromatic ketone in the presence of borane to form the catalyst–alkoxyborane adduct with a B-O-B-N four-membered ring. The ab initio molecular orbital method is employed to study the structures of the catalyst–alkoxyborane adduct. All the calculated systems are optimized completely by means of the Hartree–Fock method at 6-31g* basis sets. The B-O-B-N four-membered ring is stable, although there is strong tensile stress in the four-membered ring. The catalyst–alkoxyborane adduct exists in four stable structures. Among these structures, the largest energy difference is only about 4 kJ/mol. In the catalyst–alkoxyborane adduct, the B(2)N(3) bond in the catalyst is weakened greatly. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 78: 261–268, 2000

Quantum chemical study on enantioselective reduction of aromatic ketones catalyzed by chiral cyclic sulfur-containing oxazaborolidines. Part 3. Structures of catalyst–alkoxyborane adducts

Quantum chemical study on enantioselective reduction of aromatic ketones catalyzed by chiral cyclic sulfur-containing oxazaborolidines. Part 3. Structures of catalyst–alkoxyborane adducts

Symmetric Borohydride Reduction of Ketones by Unsymmetrical Co(II) Chiral Salen Complexes

New unsymmetrical chiral Co(II) salen complexes were synthesized and the efficiency of these catalysts was examined in the enantioselective reduction of aromatic ketones. The higher level of enantioselectivity was attainable over chiral Co(II) salen complexes prepared from salicylaldehyde and 2-formyl-4,6-di-tert-butylphenol derivatives.