41521-04-4

Upstream product

• 75-09-2 dichloromethane 
• 104-88-1 4-chlorobenzaldehyde 
• 5157-57-3 2,2-dichloro-1-(4-chlorophenyl)ethanone 
• 99-91-2 para-chloroacetophenone 
• 5333-82-4 2,2,2-trichloro-1-(4-chloro-phenyl)-ethanol 
• 555-31-7 aluminum isopropoxide 

Downstream Products

• 72-54-8 1,1-Dichloro-2,2-bis(p-chlorophenyl)ethane 
• 16608-27-8 1,1-Dichlor-2-(p-chlorphenyl)-2-(p-iodphenyl)ethan 
• 73040-66-1 5-(4-chlorophenyl)-2-amino-1,3-thiazole 
• 1022-22-6 1-chloro-2,2-bis(p-chlorophenyl)ethylene 
• 183430-89-9 2,2-dichloro-1,1-bis(4-chloro-3-nitrophenyl)ethane 
• 73040-67-2 N-[5-(4-chloro-phenyl)-thiazol-2-yl]-acetamide 
• 5157-57-3 2,2-dichloro-1-(4-chlorophenyl)ethanone 

Relevant academic research and scientific papers

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).

Laccase/TEMPO-mediated system for the thermodynamically disfavored oxidation of 2,2-dihalo-1-phenylethanol derivatives

An efficient methodology to oxidize β,β-dihalogenated secondary alcohols employing oxygen was achieved in a biphasic medium using the laccase from Trametes versicolor/TEMPO pair, providing the corresponding ketones in a clean fashion under very mild conditions. Moreover, a chemoenzymatic protocol has been applied successfully to deracemize 2,2-dichloro-1-phenylethanol combining this oxidation with an alcohol dehydrogenase-catalyzed bioreduction. the Partner Organisations 2014.

Reductive Addition of Polyhalomethanes and Their Related Compounds to Aldehydes and 1,2-Elimination of the Coupling Products in a Pb/Al Bimetal Redox System

A Pb/Al bimetal system was used to carry out reductive addition of tetrachloromethane, tetrabromomethane, bromotrichloromethane, trichloroacetamide, and trichloroacetonitrile to aldehydes.Subsequent 1,2-elimination of the halogen atom and hydroxyl group from the coupling products was also performed with the Pb/Al bimetal system.The technology was successfully applied to stereocontrolled syntheses of ethyl trans- and cis-3-(2,2-dihaloethenyl)-2,2-dimethylcyclopropanecarboxylates.