Sulfonyl oxygen

Oxygen-17 NMR spectroscopy has an immense potential for structural analysis of cyclic sulfoxides and sulfones as well as for providing insight into the nature of bonding within these two functional groups . Indeed, in addition to data concerning the NMR chemical shifts for several cyclic sulfoxides and sulfones, NMR chemical shift differences between several diastereotopic sulfonyl oxygens in both cyclic and acyclic systems have been reported . 

Representatives of the bridged sulfone system 70 have been subjected to ruthenium catalysed ring-closing metathesis reactions (Grubbs catalyst) and shown to afford, in low yields, a few selected cyclic dimers and trimers, of all the possibilities available. The diastereoselectivities observed were rationalised in terms of kinetic control involved with internal ruthenium/sulfonyl oxygen coordination . 

The sulfonyl group is achiral in itself but has prochiral oxygens, and sultanas have served as important auxiliaries in chiral reactions. Scheme 4 shows a simple example of selective coordination of a chiral Lewis acid to the sulfonyl oxygen. 

Electron-donating substituents make the aromatic subsU ate more reactive than benzene and lead to o,/ -orientation, while electron-withdrawing substituents decrease the reactivity and give mostly m-orientation products. The detailed mechanism of the formation of the a complex has been studied by oxygen-18 labeling of the sulfonyl oxygen in p-nitrobenzenesulfonyl peroxide. The ionic mechanism for aromatic substitution by sulfonyl peroxides has been confirmed by carrying out the substitution reaction in the presence of redox catalysts such as copper and cobalt salts and aluminum chloride. Small differences in the rate of the products can be found in the presence or absence of these additives, and it has been concluded that the ionic mechanism accounts satisfactorily for these results. ... 

Well-characterized 2-(chloromercurio) derivatives of 1-acetyl- and l-(phenylsulfonyl)pyrrole were prepared by reaction of HgCl2. These can be converted to />/s-(pyrrol-2-yl (mercury compounds or into ruthenium and osmium complexes by transmetallation. In all of these complexes there is coordination between the acetyl or sulfonyl oxygen and the metal, but the chelation is much tighter in the Ru and Os complexes <95JOM(491 )219> To date, the reactivity of these compounds has not been explored. 

A class of HIV-l protease inhibitors extensively examined in our department are the cyclic sulfamides [73,74]. These compounds are related to our linear 1,2-dihydroxyethylene inhibitors described above in that they are also derived from L-mannitol and employ a 1,2-dihydroxyethylene transition-state isostere. These cyclic inhibitors are comprised of seven-membered rings where the sulfonyl oxygens are designed to displace a structural water in the enzyme when the inhibitors bind to the active site [73]. The synthesis of the... 

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