42246-05-9

Upstream product

• 16821-32-2 6-methoxy-1,2,3,4-tetrahydronaphthalen-1-ol 
• 1078-19-9 6-methoxy-3,4-dihydro-1(2H)-naphthalenone 

Relevant academic research and scientific papers

Efficient enantioselective reduction of ketones with Daucus carota root

A novel and efficient reduction of various prochiral ketones such as acetopehones, α-azido aryl ketones, β-ketoesters, and aliphatic acyclic and cyclic ketones to the corresponding optically acive secondary alcohols with moderate to excellent chemical yield was achieved by using Daucus carota, root plant cells under extremely mild and environmentally benign conditions in aqueous medium, has been described. Many of these optically active alcohols are the potential chiral building blocks for the synthesis of pharmaceutically important molecules and asymmetric chiral ligands. Hence, this biocatalytic approach is found to be the most suitable for the preparation of a wide range of chiral alcohols and gave inspiration for the development of a new biotechnological process.

Ru-catalyzed mechanochemical asymmetric transfer hydrogenations in aqueous media using chitosan as chirality source

As the demand for sustainable methods increases, synthetic chemistry is focusing on the application of environmentally benign methods, such as fast reactions induced by alternative energy transmission. Chitosan is a chiral biopolymer of natural origin, which can be used in asymmetric catalysis. The application of Ru-chitosan complexes along with the mechanochemical activation may open great opportunities for sustainable preparation of optically pure alcohols. In the present study, we optimized the mechanochemical asymmetric transfer hydrogenation of 4-chromanone, carried out in a mixing mill. The reaction was catalyzed by the in situ formed Ru-chitosan complex, applying HCOONa as the hydrogen donor in aqueous media. We examined the mechanical effects of different grinding media sizes, then explored the scope of the system using 24 prochiral ketones, which ranged from hetero- and carbocyclic ketones to acetophenone derivatives. In most of the cases, the reactions were successfully scaled up to 1 mmol and the products were isolated in good yields and outstanding enantioselectivities. Our present study is a significant step forward to the development of environmentally benign and sustainable enantioselective processes, as the alternative activation method provided optically enriched alcohols using a biodegradable chirality source in aqueous media.

Design of Ru(II)-NHC-Diamine Precatalysts Directed by Ligand Cooperation: Applications and Mechanistic Investigations for Asymmetric Hydrogenation

A modular synthesis of Ru(II)-NHC-diamine complexes from readily available chiral N-heterocyclic carbenes (NHCs) and chiral diamines is disclosed for the first time. The well-defined Ru(II)-NHC-diamine complexes show unique structure and coordination chem

3-Menthoxybiphenyl-4-carboxylic acid: a versatile resolving agent and reagent for determination of the absolute configuration of benzylic alcohols

A versatile reagent for the chiral resolution and determination of the absolute configuration of benzylic alcohols, (?)-3-menthoxybiphenyl-4-carboxylic acid, is reported. (?)-3-menthoxybiphenyl-4-carboxylic acid was condensed with racemic benzylic alcohol

Third-Generation Amino Acid Furanoside-Based Ligands from d-Mannose for the Asymmetric Transfer Hydrogenation of Ketones: Catalysts with an Exceptionally Wide Substrate Scope

A modular ligand library of α-amino acid hydroxyamides and thioamides was prepared from 10 different N-tert-butyloxycarbonyl-protected α-amino acids and three different amino alcohols derived from 2,3-O-isopropylidene-α-d-mannofuranoside. The ligand library was evaluated in the half-sandwich ruthenium- and rhodium-catalyzed asymmetric transfer hydrogenation of a wide array of ketone substrates, including simple as well as sterically demanding aryl alkyl ketones, aryl fluoroalkyl ketones, heteroaromatic alkyl ketones, aliphatic, conjugated and propargylic ketones. Under the optimized reaction conditions, secondary alcohols were obtained in high yields and in enantioselectivities up to >99%. The choice of ligand/catalyst allowed for the generation of both enantiomers of the secondary alcohols, where the ruthenium-hydroxyamide and the rhodium-thioamide catalysts act complementarily towards each other. The catalytic systems were also evaluated in the tandem isomerization/asymmetric transfer hydrogenation of racemic allylic alcohols to yield enantiomerically enriched saturated secondary alcohols in up to 98% ee. Furthermore, the catalytic tandem α-alkylation/asymmetric transfer hydrogenation of acetophenones and 3-acetylpyridine with primary alcohols as alkylating and reducing agents was studied. Secondary alcohols containing an elongated alkyl chain were obtained in up to 92% ee. (Figure presented.).

Ansa-Ruthenium(II) Complexes of R2NSO2DPEN-(CH2)n(η6-Aryl) Conjugate Ligands for Asymmetric Transfer Hydrogenation of Aryl Ketones

New 3rd generation designer ansa-ruthenium(II) complexes featuring N,C-alkylene-tethered N,N-dialkylsulfamoyl-DPEN/η6-arene ligands, exhibited good catalytic performance in the asymmetric transfer hydrogenation (ATH) of various classes of (het)aryl ketones in formic acid/triethylamine mixture. In particular, benzo-fused cyclic ketones furnished 98 to >99.9% ee using a low catalyst loading.

Zinc Acetate-Catalyzed Enantioselective Hydrosilylation of Ketones

Zinc acetate complexes with a chiral diphenylethylenediamine (DPEDA)-derived ligand have been proved to be efficient catalysts for the enantioselective hydrosilylation of aryl ketones. Replacing pyrophoric dialkylzinc with the readily available zinc salt simplifies the procedures and provides excellent conversions (up to >99%) and enantioselectivities (ees up to 97%).

Homogeneous enantioselective catalysis in a continuous-flow microreactor: Highly enantioselective borohydride reduction of Ketones catalyzed by optically active cobalt complexes

Highly enantioselective homogeneous catalysis under continuous-flow conditions was established for the cobalt-catalyzed borohydride reduction of tetralone derivatives. A microreactor allowed higher reaction temperature with the residence time of 12 min than the corresponding batch system to maintain enantioselectivity as well as reactivity. The present system was directly applied to gram-scale synthesis to afford the reduced product with 92% ee.

Application of proline-functionalised 1,2-diphenylethane-1,2-diamine (DPEN) in asymmetric transfer hydrogenation of ketones

A series of enantiomerically pure ligands containing a combination of proline and DPEN groups have been prepared and employed in the asymmetric transfer hydrogenation of ketones. In the case of cyclic ketones, alcohols with ee values of up to 98% were obtained.

Chiral ruthenabicyclic complexes: Precatalysts for rapid, enantioselective, and wide-scope hydrogenation of ketones

A novel ruthenabicyclic complex with base shows excellent catalytic activity in the asymmetric hydrogenation of ketones. The turnover frequency of the hydrogenation of acetophenone reaches about 35 000 min-1 in the best case, affording 1-phenylethanol in >99% ee. Several aliphatic and base-labile ketones are smoothly converted to the corresponding alcohols in high enantioselectivity. The catalytic cycle for this hydrogenation, in which the ruthenabicyclic structure of the catalyst is maintained, is proposed on the basis of the deuteration experiment and spectroscopic analysis data.