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Strategic Application of Residence-Time Control in Continuous-Flow Reactors.

Mándity IM, Ötvös SB, Fülöp F - ChemistryOpen (2015)

Bottom Line: As a sustainable alternative for conventional batch-based synthetic techniques, the concept of continuous-flow processing has emerged in the synthesis of fine chemicals.Systematic tuning of the residence time, a key parameter of continuous-reaction technology, can govern the outcome of a chemical reaction by determining the reaction rate and the conversion and by influencing the product selectivity.Such a fine reaction control cannot be performed in conventional batch reaction set-ups.

View Article: PubMed Central - PubMed

Affiliation: Institute of Pharmaceutical Chemistry, University of Szeged Eötvös u. 6, H-6720, Szeged, Hungary.

ABSTRACT
As a sustainable alternative for conventional batch-based synthetic techniques, the concept of continuous-flow processing has emerged in the synthesis of fine chemicals. Systematic tuning of the residence time, a key parameter of continuous-reaction technology, can govern the outcome of a chemical reaction by determining the reaction rate and the conversion and by influencing the product selectivity. This review furnishes a brief insight into flow reactions in which high chemo- and/or stereoselectivity can be attained by strategic residence-time control and illustrates the importance of the residence time as a crucial parameter in sustainable method development. Such a fine reaction control cannot be performed in conventional batch reaction set-ups.

No MeSH data available.


Related in: MedlinePlus

CF reaction of 1-bromo-2,5-dimethoxy-3-nitrobenzene with PhLi, followed by the residence-time-controlled transformation of the organolithium intermediate with isobutyraldehyde.11
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sch02: CF reaction of 1-bromo-2,5-dimethoxy-3-nitrobenzene with PhLi, followed by the residence-time-controlled transformation of the organolithium intermediate with isobutyraldehyde.11

Mentions: The nitro group reacts vigorously with aryllithiums, and accordingly, the generation of nitro-substituted organolithium compounds in batch macroreactors is difficult; very low temperature is usually needed to gain sufficient control over the reaction selectivity. However, with flash chemistry, this problem can be overcome and nitro-substituted aryllithium reagents can easily be obtained via halogen–lithium exchange reactions in very short residence times.11 Accurate control over the residence time permits the selective use of either the kinetically or the thermodynamically preferred organolithium intermediate in the reaction of 1-bromo-2,5-dimethoxy-3-nitrobenzene with phenyllithium (PhLi) at −48 °C (Scheme 2).


Strategic Application of Residence-Time Control in Continuous-Flow Reactors.

Mándity IM, Ötvös SB, Fülöp F - ChemistryOpen (2015)

CF reaction of 1-bromo-2,5-dimethoxy-3-nitrobenzene with PhLi, followed by the residence-time-controlled transformation of the organolithium intermediate with isobutyraldehyde.11
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4522171&req=5

sch02: CF reaction of 1-bromo-2,5-dimethoxy-3-nitrobenzene with PhLi, followed by the residence-time-controlled transformation of the organolithium intermediate with isobutyraldehyde.11
Mentions: The nitro group reacts vigorously with aryllithiums, and accordingly, the generation of nitro-substituted organolithium compounds in batch macroreactors is difficult; very low temperature is usually needed to gain sufficient control over the reaction selectivity. However, with flash chemistry, this problem can be overcome and nitro-substituted aryllithium reagents can easily be obtained via halogen–lithium exchange reactions in very short residence times.11 Accurate control over the residence time permits the selective use of either the kinetically or the thermodynamically preferred organolithium intermediate in the reaction of 1-bromo-2,5-dimethoxy-3-nitrobenzene with phenyllithium (PhLi) at −48 °C (Scheme 2).

Bottom Line: As a sustainable alternative for conventional batch-based synthetic techniques, the concept of continuous-flow processing has emerged in the synthesis of fine chemicals.Systematic tuning of the residence time, a key parameter of continuous-reaction technology, can govern the outcome of a chemical reaction by determining the reaction rate and the conversion and by influencing the product selectivity.Such a fine reaction control cannot be performed in conventional batch reaction set-ups.

View Article: PubMed Central - PubMed

Affiliation: Institute of Pharmaceutical Chemistry, University of Szeged Eötvös u. 6, H-6720, Szeged, Hungary.

ABSTRACT
As a sustainable alternative for conventional batch-based synthetic techniques, the concept of continuous-flow processing has emerged in the synthesis of fine chemicals. Systematic tuning of the residence time, a key parameter of continuous-reaction technology, can govern the outcome of a chemical reaction by determining the reaction rate and the conversion and by influencing the product selectivity. This review furnishes a brief insight into flow reactions in which high chemo- and/or stereoselectivity can be attained by strategic residence-time control and illustrates the importance of the residence time as a crucial parameter in sustainable method development. Such a fine reaction control cannot be performed in conventional batch reaction set-ups.

No MeSH data available.


Related in: MedlinePlus