Strategy level separations

D.P. Curran, Strategy-level separations in organic synthesis from planning to practice, Angew Chem, Int Ed Engl 37 1174-1196 1998. 

D. P. Curran, Strategy-Level Separations in Organic Synthesis From Planning to Practice , Angew. Chem, Int. Ed Engl. 1998, 37,1175. 

Isolation and purification of reaction products Despite recent advances in methodologies for the synthesis of very complex molecules, one important aspect of synthesis has not changed much over the past decades isolation and purification. A recent excellent review entitled Strategy-Level Separations in Organic Synthesis From Planning to Practice discusses various techniques for the separation of reaction mixtures. The yield and hence the utility of every reaction is limited by the ability to separate and recover the reaction product from other materials. 

In a simple view, both heavy and light fluorous molecules can be divided into an organic domain that controls the reaction chemistry and a fluorous domain that controls the separation chemistry. This view coincides with the principles of strategy level separations, which dictate that reactions should be purified only by simple workup-level procedures whenever possible. In the ideal separation, the target products of a reaction partitions into a phase that is different from all of the other reaction components, thereby allowing rapid and in many cases environment friendly isolation. The fluorous ponytails (permanent domains) or tags (temporary domains) on both heavy and light fluorous molecules allow them to partition into a fluorous phase under suitable workup conditions. 

Another strategy to separate the QM part from the MM one is to freeze the pair of electrons in the broken bond (assumed to be a single bond). This has been suggested first by Warshel and Levitt [22] and the method has been developed recently at the semiempirical [23,241 and ab initio levels [26-281 as the local self-consistent field (LSCF) method. 

Fig. 1.3 Prediction of the most appropriate subcellular targeting strategies by agroinfiltration. The levels of an industrial enzyme (IE) are shown in agroinfiltrated and transgenic alfalfa leaves using different subcellular targeting peptides. Equal amounts of total soluble leaf proteins were separated by SDS-PAGE and blotted onto a PVDF membrane. Polyclonal anti-IE IgGs were used for detection.

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