Polymer-supported reagents sulfonic acid

Polymer supported reagents, catalysts, protecting groups, and mediators can be used in place of the corresponding small molecule materials (Sherrington, 1991 Sundell and Nasman, 1993). The reactive species is tightly bound to a macromolecular support which immobilizes it. This generally makes toxic, noxious, or corrosive materials much safer. The use of polystyrene sulfonic acid catalyst for the manufacture of methyl r-butyl... 

Organic hydroperoxides are generally used for the preparation of sulfoxides from sulfides, - while sulfones can be obtained in neutral organic solvents in the presence of metal catalysts such as V, Mo and Ti oxides at 50-70 C. Two polymer-supported reagents which involve peroxy acid groups and bound hypervalent vanadium(V) and molybdenum(VI) compounds have been developed for facile oxidation of sulfoxides to sulfones. 

Fig. 6. Polymer-supported IBX (resin 5) can be activated and recycled with monoperoxy sulfonic acid (Caro s acid). The polymer reagent is capable of alcohol oxidations, dehydrogenations, and radical cyclization reactions.

Several coumarins starting from appropriate phenolic compounds have been synthesized in a microwave-assisted reaction using trifluoroacetic acid, which acts as an acidic reagent and a reaction medium. Alternatively, polymer-supported sulfonic acid Amberlyst-15 could also be utilized to assist the formation of coumarins. The usage of a particularly built microwave synthesizer with liquid handling tools rendered the automated synthesis of a coumarin library achievable (07CHE151). 

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