Byproduct Sequestration

Carboxylic acids generated in acylation reactions have been effectively sequestered by ion pair formation with Amberlite IRA-68 ion exchange resin. Similarly, 4-nitrophenoxide formed in acylations of 4-nitrophenyl esters has been captured by anion exchange with the quaternary ammonium hydroxide resin 12. An exception to ion pair-mediated sequestration of byproducts is the polyamine functionalized resin 3 that was shown to covalently sequester the (3-methoxy enone hydrolysis byproduct from Danishefsky s diene via imine formation.  

It is anticipated that additional byproduct-sequestering resins will be reported in the near future, highlighting novel ionic and covalent sequestration strategies. In pai icular, the application of byproduct-sequestering resins (other than acid scavengers) to help drive reactions to completion would demonstrate a significant advance in this area.  

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Donahoe, R. J. (2004). Secondary Mineral Formation in Coal Combustion Byproduct Disposal Facilities Implications for Trace Element Sequestration. In Giere, R. Stille, P. (eds) Energy, Waste, and the Environment a Geochemical Perspective. Geological Society, London, Special Publications, 236, 641-658. 

Secondary mineral formation in coal combustion byproduct disposal facilities implications for trace element sequestration... 

Poorly reactive (poorly sequestrable) byproducts are more frequently encountered than poorly sequestrable reactants. A few reports have appeared describing the use of soluble bifunctional linking reagents to chemically tag... 

In a network of autocatalytic feedback loops (of which we here do consider only those processes related to Mg) control functions which give rise to either autocatalyst supply (sequestration from the enviromnent) or loss (abstraction or precipitation by parasitic byproducts) several different chemical species may interact or cooperate to achieve the above kinds of control (Eiswirth et al. 1991b), two such side-loops cause somewhat increased topological network complexity rather than fundamentally changing network dynamics. 

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