126135-40-8

Upstream product

• 30913-86-1 4-(4-bromo-phenyl)-4-oxo-butyric acid methyl ester 
• 6340-79-0 4-oxo-4-(4-bromophenyl)butanoic acid 
• 1122-91-4 4-bromo-benzaldehyde 
• 292638-85-8 acrylic acid methyl ester 
• 108-86-1 bromobenzene 

Downstream Products

• 128994-29-6 (S)-(-)-γ-(p-Bromophenyl)-γ-butyrolactone 
• 126135-43-1 (R)-(+)-γ-(p-Bromophenyl)-γ-butyrolactone 

Relevant academic research and scientific papers

A substrate-binding metal-organic layer selectively catalyzes photoredox ene-carbonyl reductive coupling reactions

Intermolecular photoredox ene-carbonyl reductive coupling reactions typically have low product selectivity owing to competing dimerization and/or reduction of ketyl radicals. Herein, we report a metal-organic layer (MOL), Hf-Ir-OTf, as a bifunctional photocatalyst for selective photoredox reductive coupling of ketones or aldehydes with electron-deficient alkenes. Composed of iridium-based photosensitizers (Ir-PSs) and triflated Hf12 clusters, Hf-Ir-OTf uses Lewis acidic Hf sites to bind and activate electron-deficient alkenes to accept ketyl radicals generated by adjacent Ir-PSs, thereby suppressing undesired dimerization and reduction of ketyl radicals to enhance the selectivity for the cross-coupling products. The MOL-catalyzed reductive coupling reaction accommodates a variety of olefinic substrates and tolerates reducible groups, nicely complementing current methods for cross-coupling reactions.

Biocatalytic Asymmetric Reduction of γ-Keto Esters to Access Optically Active γ-Aryl-γ-butyrolactones

An efficient stereoselective syntheses of a series of functionalized optically active γ-aryl-γ-butyrolactones is achieved by enzymatic asymmetric reduction of the corresponding sterically demanding γ-keto esters employing wild-type and recombinant alcohol dehydrogenases. The best stereoselectivities for the reduction via hydrogen transfer was obtained with two short chain dehydrogenases (SDRs) of complementary stereospecificity from Aromatoleum aromaticum, namely the Prelog-specific NADH-dependent (S)-1-phenylethanol dehydrogenase [(S)-PED] and the anti-Prelog-specific (R)-1-(4-hydroxyphenyl)-ethanol dehydrogenase [(R)-HPED], respectively.Biotransformations catalyzed by both enzymes, followed by TFA-catalyzed cyclization of the resulting γ-hydroxy esters, furnished the respective (S)- and (R)-configured products with exquisite optical purity (up to >99% ee). The synthetic value was demonstrated on preparative scale for the asymmetric bioreduction of the model compound, methyl 4-oxo-4-phenylbutanoate, affording optically pure (S)-γ-phenyl-γ-butyrolactone (>99% ee) in 67–74% isolated yield at 89–95% conversion depending on the applied scale. (Figure presented.).

Asymmetric synthesis of di- and trisubstituted cyclopropanes through an intramolecular ring closure

An asymmetric synthesis of di- and trisubstituted cyclopropanes proceeding through an intramolecular ring closure of activated chiral benzyl alcohols has been developed. The chiral alcohol intermediates are obtained from asymmetric reduction of readily av

Process for the stereoselective reduction of derivatives of 4-aryl-4-oxobutyric acid

A method for the stereoselective production of 4-aryl-4-hydroxybutanoic acid derivatives involves reduction of the corresponding 4-keto-acid derivative with formic acid and/or formates in presence of a ruthenium-containing catalyst and amine(s). A method

Catalytic osmium-assisted oxidative cleavage of olefins

An osmium-assisted process for the oxidative cleavage of oxidizable organic compounds such as unsaturated organic compounds, including alkenes and olefins into aldehydes, carboxylic acids, esters, or ketones. The process uses a metal catalyst comprising osmium and a peroxy compound selected from the group consisting of peroxymonosulfuric acid and salts thereof to oxidatively cleave the oxidizable organic compound. In particular, the process enables aldehydes, carboxylic acids, esters, or ketones to be selectively produced from the corresponding mono-, 1,1-di-, 1,2-di-, tri-, or tetra-substituted olefins in a reaction that produces the result of ozonolysis but with fewer problems. The present invention further provides a process for oxidizing an aldehyde alone or with the osmium in an interactive solvent to produce an ester or carboxylic acid.

Lipase-Catalyzed Preparation of Optically Active γ-Butyrolactones in Organic Solvents

Lipases in anhydrous organic solvents catalyze the lactonization of esters of γ-hydroxy carboxylic acids with a high degree of stereospecifity.Under these conditions the lipases exhibit both enantioselectivity and prochiral selectivity.We exploited the enzymes' enantioselectivity for synthesis of chiral lactones from racemic γ-hydroxy esters and their prochiral stereospecifity, i.e. the ability to discriminate between enantiotopic groups of a prochiral molecule, for the enantioconvergent lactonization of symmetrical γ-hydroxy diesters.This approach was used to develop a convenient, high yielding, and stereoselective route to several optically active γ-substituted γ-butyrolactones.