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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.


High-resolution residence-time control.7
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fig01: High-resolution residence-time control.7

Mentions: Yoshida and co-workers have recently introduced the concept of ‘flash chemistry′, for flow reactions involving 1) fast consecutive transformations and reactive intermediates, 2) competing reaction pathways, 3) highly exothermic transformations, 4) undesired byproduct formation, and 5) transformations leading to labile products which readily decompose.7 These reactions are difficult (or sometimes impossible) to accomplish in traditional segmented unit operations, and selectivity issues often reduce their practical applicability. Flash chemical synthesis relies on high-resolution control of the residence time within a flow microreactor. For precise control over the reaction outcome, mixing should take place in a much shorter time than the residence time in the active reactor zone, which necessitates the use of micromixers that allow extremely fast mixing (Figure 1). In the last few years, there have been a huge number of outstanding contributions to the flash chemistry concept in various fields of organic synthesis (such as organolithium chemistry, cross-coupling reactions, and organo fluorine chemistry), and they have recently been reviewed extensively.8 Thus, only several selected examples will be detailed in the present manuscript.


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

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

High-resolution residence-time control.7
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig01: High-resolution residence-time control.7
Mentions: Yoshida and co-workers have recently introduced the concept of ‘flash chemistry′, for flow reactions involving 1) fast consecutive transformations and reactive intermediates, 2) competing reaction pathways, 3) highly exothermic transformations, 4) undesired byproduct formation, and 5) transformations leading to labile products which readily decompose.7 These reactions are difficult (or sometimes impossible) to accomplish in traditional segmented unit operations, and selectivity issues often reduce their practical applicability. Flash chemical synthesis relies on high-resolution control of the residence time within a flow microreactor. For precise control over the reaction outcome, mixing should take place in a much shorter time than the residence time in the active reactor zone, which necessitates the use of micromixers that allow extremely fast mixing (Figure 1). In the last few years, there have been a huge number of outstanding contributions to the flash chemistry concept in various fields of organic synthesis (such as organolithium chemistry, cross-coupling reactions, and organo fluorine chemistry), and they have recently been reviewed extensively.8 Thus, only several selected examples will be detailed in the present manuscript.

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.