Salting-out reagents

Despite the fact that Diels and Alder carried out a cycloaddition in water [2], it was not until 1980 that it was reported that large accelerations in the rates of the Diels-Alder reaction could be achieved in water [3], In addition, selectivity towards the endo product was also increased [4], For example, a 700-fold acceleration in the rate of reaction between cyclopentadiene and 3-buten-2-one (Scheme 7.3) was found in water as compared to reaction in 2,2,4-trimethylpentane. The addition of lithium chloride as a salting-out reagent... 

B) medium effects in the aqueous phase, including the effect of non-aqueous additives, salting-out reagents and alkaline solutions ... 

Salts. Salts trap water and unveil the hydrophobic areas on the surface of enzyme molecules resulting in aggregation their precipitation. Salting out depends on hydrophobic interaction, alteration of pH or ionic strength, polarity and temperature. The most commonly used reagents are ammonium and sodium sulphate. 

Ban et al. reviewed the reduction properties of several salt-free reagents for Np(VI) and Pu(IV) to choose selective reductants that reduce only Np(VI) to Np(V) for separating Np from U and Pu in TBP by reductive back-extraction (165). Allylhydrazine was proposed as a candidate for selective Np(VI) reduction, and it was confirmed by a batch experiment that allylhydrazine reduced almost all Np(VI) to Np(V) and back-extracted Np from the organic phase (30% TBP/n-dodecane) to the aqueous phase (3 M HN03) within 10 minutes. A continuous countercurrent experiment using a miniature mixer-settler was carried out with allylhydrazine at room temperature. At least 91% of Np(VI) fed to the mixer-settler was selectively reduced to Np(V) and separated from U and Pu. 

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