2612-41-1

Upstream product

• 140-10-3 (E)-3-phenylacrylic acid 
• 103-64-0 bromostyrene 
• 75-25-2 Bromoform 
• 100-52-7 benzaldehyde 
• 98-86-2 acetophenone 
• 93-89-0 benzoic acid ethyl ester 
• 2612-42-2 (dibromomethyl)trimethylsilane 
• 13665-04-8 2,2-dibromoacetophenone 
• 17609-20-0 dibromomethyl-magnesium chloride 
• 2425-28-7 2-Bromo-1-phenylethanol 
• 74-95-3 1,1-dibromomethane 

Downstream Products

• 21504-23-4 2,2-dimethoxy-1-(phenyl)ethanol 
• 6111-82-6 (E)-1-phenyl-1-hexene 
• 15325-54-9 (Z)-hex-1-en-1-ylbenzene 
• 120809-73-6 1,1-dibromo-2-phenyl-2-(trimethylsiloxy)ethane 
• 99511-02-1 (Z)-2-bromo-1-phenylethylene acetate 
• 103-64-0 bromostyrene 
• 33551-66-5 (2,2-dibromo-1-fluoroethyl)benzene 

Relevant academic research and scientific papers

Steric vs. electronic effects in the Lactobacillus brevis ADH-catalyzed bioreduction of ketones

Lactobacillus brevis ADH (LBADH) is an alcohol dehydrogenase that is commonly employed to reduce alkyl or aryl ketones usually bearing a methyl, an ethyl or a chloromethyl as a small ketone substituent to the corresponding (R)-alcohols. Herein we have tested a series of 24 acetophenone derivatives differing in their size and electronic properties for their reduction employing LBADH. After plotting the relative activity against the measured substrate volumes we observed that apart from the substrate size other effects must be responsible for the activity obtained. Compared to acetophenone (100% relative activity), other small substrates such as propiophenone, α,α, α-trifluoroacetophenone, α-hydroxyacetophenone, and benzoylacetonitrile had relative activities lower than 30%, while medium-sized ketones such as α-bromo-, α,α-dichloro-, and α,α-dibromoacetophenone presented relative activities between 70% and 550%. Moreover, the comparison between the enzymatic activity and the obtained final conversions using an excess or just 2.5 equiv. of the hydrogen donor 2-propanol, denoted again deviations between them. These data supported that these hydrogen transfer (HT) transformations are mainly thermodynamically controlled. For instance, bulky α-halogenated derivatives could be quantitatively reduced by LBADH even employing 2.5 equiv. of 2-propanol independently of their kinetic values. Finally, we found good correlations between the IR absorption band of the carbonyl groups and the degrees of conversion obtained in these HT processes, making this simple method a convenient tool to predict the success of these transformations. The Royal Society of Chemistry.

Expanding the scope of alcohol dehydrogenases towards bulkier substrates: Stereo- and enantiopreference for α,α-dihalogenated ketones

Alcohol dehydrogenases (ADHs) were identified as suitable enzymes for the reduction of the corresponding α,α-dihalogenated ketones, obtaining optically pure β,β-dichloro- or β,β-dibromohydrins with excellent conversions and enantiomeric excess. Among the different biocatalysts tested, ADHs from Rhodococcus ruber (ADH-A), Ralstonia sp. (RasADH), Lactobacillus brevis (LBADH), and PR2ADH proved to be the most efficient ones in terms of activity and stereoselectivity. In a further study, two racemic α-substituted ketones, namely α-bromo- α-chloro- and α-chloro-α-fluoroacetophenone were investigated to obtain one of the four possible diastereoisomers through a dynamic kinetic process. In the case of the brominated derivative, only the (1R)-enantiomer was obtained by using ADH-A, although with moderate diastereomeric excess (>99 % ee, 63 % de), whereas the fluorinated ketone exhibited a lower stereoselectivity (up to 45 % de). Bulking up: A series of β,β-dihalohydrins are obtained through alcohol dehydrogenase (ADH) catalyzed bioreduction of the synthesized α,α-dihalogenated ketones. Two racemic acetophenone derivatives are also subjected to this protocol to obtain stereoenriched alcohols through dynamic kinetic resolution (DKR).

Bromoform activation. TiCl4-Mg-promoted CHBr2 - and CBr3- transfer to a variety of aldehydes and ketones

TiCl4-Mg can mediate addition of CHBr3 to a variety of aldehydes and ketones to form dibromomethyl carbinols and also be used to effect CBr3 transfer to carbonyl groups to form tribromomethyl carbinols. The successful application of TiCl4-Mg-promoted coupling of CHBr3 with various carbonyl compounds, especially in the case of highly enolizable ketones such as 2-indanone and β-tetralone, highlights the extraordinary reactivity and selectivity and the weakly basic nature of this system.

A fast and selective decarboxylative difunctionalization and cyclization for easy access to gem-dihalo alcohol, ether, ester and bromo-1,4-dioxane

A general strategy for fast decarboxylative difunctionalization to gem-dihalohydrin, gem-dihaloether, gem-dibromoester and cyclized bromo-1,4-dioxane synthons with outstanding regio- and stereoselectivity is demonstrated. The Royal Society of Chemistry 20

Facile aerobic photo-oxidative synthesis of phenacyl iodides and bromides from styrenes using I2 or aqueous HBr

We report a useful method for facile synthesis of phenacyl iodides and bromides from styrene derivatives by aerobic photo-oxidation using I2 or 48% aqueous HBr in the presence of water. Georg Thieme Verlag Stuttgart - New York.

Enantiomerically pure α-methoxyaryl acetaldehydes as versatile precursors: a facile chemo-enzymatic methodology for their preparation

A facile and efficient synthesis of optically active α-methoxyaryl acetic acids (up to 95% ee), α-methoxyaryl ethanols (up to 93% ee) and α-methoxyaryl acetonitriles (up to 93% ee) was achieved via Arthrobacter sp. lipase-catalyzed kinetic resolution of masked aldehydes as the key synthons, that is, α-hydroxyaryl acetaldehyde acetals.

Stereoselective synthesis of (E)-β-arylvinyl halides by microwave-induced Hunsdiecker reaction

(E)-β-Arylvinyl halides were prepared in high yields in a short reaction (1-2 min) by microwave irradiation of the corresponding 3-arylpropenoic acids in the presence of N-halosuccinimide and catalytic LiOAc.

Catalytic Hunsdiecker reaction and one-pot catalytic Hunsdiecker-Heck strategy: Synthesis of α,β-unsaturated aromatic halides, α- (dihalomethyl)benzenemethanols, 5-aryl-2,4-pentadienoic acids, dienoates and dienamides

The reaction of α,β-unsaturated aromatic (or heteroaromatic) carboxylic acids with N-halosuccinimides (1 equiv.) and catalytic tetrabutylammonium trifluoroacetate (0.2 equiv.) in dichloroethane results in facile halodecarboxylation affording the corresponding (E)-halides in good to excellent yields. A similar reaction, but with 2 equiv. of N-halosuccinimides in acetonitrile-water (1:1 v/v) results in the exclusive formation of the corresponding α-(dihalomethyl)benzenemethanols. Furthermore, a one-pot strategy has been developed combining catalytic Hunsdiecker reaction (using tetrabutylammonium trifluoroacetate in dichloroethane) and Heck coupling (using palladium acetate/triethylamine/triphenylantimony/dichloroethane) for the synthesis of 5-aryl-2,4-pentadienoic acids, esters and amides in moderate to good yields. The natural product piperine and pipergualamine has been synthesized via the above route. Mechanistic and theoretical studies (via AM1 calculations) provide a useful insight into the mechanism of the present halodecarboxylation reaction, suggesting an ionic pathway involving the attack of the halogenium ion across the carbon-carbon double bond, triggering the elimination of carbon dioxide. (C) 2000 Elsevier Science Ltd.

Manganese (II) catalysed hunsdiecker reaction: A facile entry to α -(dibromomethyl) benzenemethanol

Manganese (II) acetate catalysed reactions of α, β-unsaturated aromatic carboxylic acids 1 with NBS (1 and 2 eq.) in MeCN / water afford haloalkenes 2 and α-(dibromomethyl) benzenemethanols 3 respectively. Copyright