96855-38-8

Upstream product

• 117465-34-6 2-bromo-1-(4-bromophenyl)ethanol 
• 99-73-0 para-bromophenacyl bromide 
• 934-94-1 1-bromo-4-bromoethynyl-benzene 
• 108-05-4 vinyl acetate 

Downstream Products

• 769944-85-6 (2S)-2-(4-bromophenyl)-piperazine-1,4-dicarboxylic acid di-tert-butyl ester 
• 62566-68-1 (R)-2-(4-bromophenyl)oxirane 

Relevant academic research and scientific papers

(2S)-2-Anilinomethylpyrrolidine: an efficient in situ recyclable chiral catalytic source for the borane-mediated asymmetric reduction of prochiral ketones in refluxing toluene

(2S)-2-Anilinomethylpyrrolidine was successfully utilized as a chiral catalytic source in the borane-mediated asymmetric reduction of prochiral ketones in refluxing toluene to provide the corresponding secondary alcohols with enantiomeric excesses up to 91%. The potential of (2S)-2-anilinomethylpyrrolidine as an in situ recyclable chiral catalytic source in the borane-mediated chiral reduction processes has also been demonstrated.

Asymmetric synthesis of α-bromohydrins by carrot root as biocatalyst and conversion to enantiopure β-hydroxytriazoles and styrene oxides using click chemistry and SN2 ring-closure

In this study we have combined the bioreduction of α-bromoketones using carrot root as biocatalyst and click chemistry for the preparation of enantiopure β-hydroxytriazoles in excellent enantiomeric excesses and yields. Moreover, we have utilized chiral α-halohydrins for the synthesis of enantiopure styrene oxides in very good yields and enantiomeric excesses. Structural assignments of the products were based on their 1H and 13C NMR data and their optical rotations. The enantiomeric excess of the chiral products was obtained by HPLC analysis.

Selective Asymmetric Transfer Hydrogenation of α-Substituted Acetophenones with Bifunctional Oxo-Tethered Ruthenium(II) Catalysts

A practical method for the asymmetric transfer hydrogenation of α-substituted ketones was developed utilizing oxo-tethered N-sulfonyldiamine-ruthenium complexes. Reduction by HCO2H and HCO2K in a mixed solvent of EtOAc/H2O allowed for the selective synthesis of halohydrins from 2-bromoacetophenone (98%) and 2-chloroacetophenone (>99%), leading to suppressed undesired side reactions stemming from formylation under the typical reaction conditions using an azeotropic 5:2 mixture of HCO2H and Et3N. A range of functional groups, such as halogens, methoxy, nitro, dimethylamino, and ester groups, were well tolerated, highlighting the potential of this method. Nearly complete selectivity with a preferable ee was maintained even with a substrate/catalyst (S/C) ratio of 5000. This catalyst system was also effective for the asymmetric reduction of α-sulfonated ketones without eroding the leaving group. (Figure presented.).

Immobilization of Amano lipase from Pseudomonas fluorescens on silk fibroin spheres: an alternative protocol for the enantioselective synthesis of halohydrins

The search for a new, efficient, cheaper and sustainable matrix for lipase immobilization is a growing area in biotechnology. Amano lipase from Pseudomonas fluorescens was immobilized on silk fibroin spheres and used in the enzymatic kinetic resolution of halohydrins, to obtain optically active epoxides (up to 99% ee), important precursors in the synthesis of derivative antifungal azoles. This paper reinforces the versatility of silk fibroin as a support for heterogeneous catalysts.

Integration of multiple active sites on large-pore mesoporous silica for enantioselective tandem reactions

Facile construction of a multifunctional heterogeneous catalyst through the assembly of Au/carbene and chiral ruthenium/diamine dual complexes in large-pore mesoporous silica was developed. This enables an efficient one-pot hydration-asymmetric transfer hydrogenation enantioselective tandem reaction of haloalkynes, affording chiral halohydrins with up to 99% enantioselectivity. Combined multifunctionalities, such as substrate-promoted silanol-functionality, BF4? anion-bonding gold/carbene and covalent-bonding chiral ruthenium/diamine active centers, contributed cooperatively to the catalytic performance.

One-Pot cascade hydration-asymmetric transfer hydrogenation as a practical strategy to construct chiral β-adrenergic receptor blockers

The facile construction of biologically active β-adrenergic receptor agonists/blockers and analogues is a great fundamental and practical challenge in medical chemistry. Herein, we report a hydration-asymmetric transfer hydrogenation cascade to realize the one-pot enantioselective transformation of aromatic haloalkynes into chiral aromatic halohydrins, which can be converted readily into chiral β-adrenergicreceptor blockers. Such a one-pot cascade process involves the Au-catalyzed hydration of aryl-substituted haloalkynes to aryl-substituted α-halomethyl ketones and the Ru-catalyzed asymmetric transfer hydrogenation of aryl-substituted α-halomethyl ketones to aryl-substituted 2-haloethanols. The significant benefits of this procedure are that it provides chiral aromatic halohydrins in high yields, with excellent enantioselectivities, and a wide variety of functional groups are tolerated under mild conditions. The study described herein offers a useful approach to construct chiral β-adrenergic blockers, which is an attractive practical organic transformation that is performed in a one-pot manner.

Asymmetric synthesis of 2-arylpiperazines

An asymmetric synthesis of 2-arylpiperazines starting from phenacyl bromides, a variety of which are easily available, has been established. The synthesis features a CBS reduction of phenacyl bromide to provide optically enriched compounds, an SN2 reaction of 1,2,3-oxathiazolidine 2-oxides with an azide anion with invert of configuration, and construction of the piperazine ring via reduction of piperazine-2,3-diones.

The Ru-catalyzed enantioselective preparation of chiral halohydrins and their application in the synthesis of (R)-clorprenaline and (S)-sotalol

The asymmetric transfer hydrogenation of a series of halo-substituted aryl methyl ketones, including those substituted in both α-methyl and aryl rings, was studied for the preparation of chiral halohydrins. Up to 99.7% ee was obtained with 2-chloro-1-(2-chlorophenyl)ethanone as the substrate and Ru-CsDPEN as the catalyst in an HCOONa/H2O system. (R)-Clorprenaline, a drug used in the treatment of respiratory disorders, such as bronchitis and asthma, and (S)-sotalol, a class-III antiarrhythmic compound, were prepared with these chiral halohydrins.

A novel C3-symmetric prolinol-squaramide catalyst for the asymmetric reduction of ketones by borane

A novel C3-symmetric prolinol-squaramide has been developed for the asymmetric reduction of ketones by borane. By using only 5 mol % catalyst 1a for the reaction, high yields and excellent enantioselectivities (up to 95% yield, 93% ee) were obtained. Moreover, 1a can be easily recovered by simple precipitation and re-used for four cycles without losing the selectivity. Copyright

Highly enantioselective bioreduction of prochiral ketones by stem and germinated plant of Brassica oleracea variety italica

An eco-friendly and environmentally benign asymmetric reduction of a broad range of prochiral ketones employing Brassica oleracea variety italica (stems and germinated plant) as a novel biocatalyst was developed. It was found that B. oleracea variety italica could be used effectively for enantioselective bioreduction in aqueous medium with moderate to excellent chemical yield and enantiomeric excess (ee). This process is more efficient and generates less waste than conventional chemical reagents or microorganisms. Both R- and S-configurations were obtained by these asymmetric reactions. The best ee were achieved for pyridine derivatives (92-99%). The ee in germinated plant reactions were significantly higher than those of stem reactions. The low cost and the easy availability of these biocatalysts suggest their possible use for large scale preparations of important chiral alcohols.