Arylations silver® trifluoromethanesulfonate

Ketone silyl enol ethers react with derivatives of diacyl azo compounds at room temperature245 or on heating242,243 (see also Eq. 82) as well as enantio-selectively under the influence of silver trifluoromethanesulfonate and BINAP (Eq. 93)244 or copper bis(oxazoline) complexes (Eq. 94). The latter is proposed to proceed via a formal hetero Diels-Alder adduct.252 Ketones themselves react with azodicarboxylic esters either thermally246,389,390 or in the presence of potassium carbonate390 but yields are low. Higher yields can be achieved with LDA,391 394 (see also Eq. 88), LiHMDS,395,396 or KOBu-r325 as the bases. Aryl diazonium... 

Diaryl sulfones. Aryl sulfonyl bromides (but not sulfonyl chlorides) react with silver trifluoromethanesulfonate in nitromethane at 0° to form unstable mixed sulfonic anhydrides (c/ 4, 533-534). These react with arenes (threefold excess) at the same temperature to give diaryl sulfones usually in yields of 80-100%. 

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