Mitsunobu reaction using fluorous reagents

Figure 7.12 Mitsunobu reaction using fluorous tagged reagents.

By such an SPE, products can be separated from perfluoro-tagged catalysts, byproducts or reagents. One example is a Mitsunobu reaction ulilizirig fluorous aza-dicarboxylate and triphenylphosphine [28]. Many more examples of the use of this... 

Several fluorous counterparts of common reagents have been reported and many of these are also commercially available. Of some interest is the development of fluorous Mitsunobu reagents. A first generation fluorous DEAD reagent was found to have poor reactivity when difficult Mitsunobu reactions were encountered it has since been replaced with two enhanced, second-generation reagents, (1) and (2), for use in parallel or sequential fluorous chromatography and rapid F-SPE isolation, respectively. 

Curran, D. P., Dandapani, S. Fluorous nucleophilic substitution of alcohols and reagents for use therein, specifically, perfluoroalkyl-containing phosphines and azodicarboxylates as polyfluorinated reagents for the Mitsunobu reaction, 2002-US26045 2003016246, 2003 (University of Pittsburgh, USA). 

In the last few years fluorous combinatorial chemistry has been extended and augmented by other fluorous techniques developed by analogy with established methods in solid-phase-supported synthesis. Use of fluorous condensation reagents for the Mitsunobu reaction [23] enables easy removal of all condensation reagents except the coupled starting materials after the reaction [24] (Scheme 3.23). A fluorous variant of the Swern [25] and Corey-Kim oxidations [26] enables handling of stoichiometric quantities of malodorous dimethyl sulfide to be avoided [27] (Scheme 3.24). 

---