Palladium-catalyzed desulfitative coupling

Using this design strategy, copper(I) carboxylates, such as Cu(l) thiophenecarboxylate (CuTC) and Cu(I) 3-methyl-salicylate (CuMeSal) proved to be uniquely effective facilitators of the pH-neutral, palladium-catalyzed desulfitative coupling of thioorganics with boronic acids and their pH-neutral transmetalation partners, organostannanes (Fig. 23.3) The literature is now replete with many examples of this chemistry (Fig. 23.4) [4, 5, 25-42]. 

All first-generation palladium-catalyzed desulfitative couplings of thioorganics and boronic acids highlighted in Fig. 23.4 require the use of stoichiometric quantities of a copper(l) carboxylate cofactor. This requirement is implicit in the mechanism of the transformation (Scheme 23.3). 

The reactivity of furan derivatives in palladium-catalyzed desulfitative arylation was studied. Alkyl-substituted furan derivatives were successfully coupled with a variety of benzenesulfonyl chlorides using a phosphine-free catalyst regioselective arylation at C-5 of the furan was observed in all cases (14S2515). 

Dubbaka, S.R. and Vogel, P. (2005) Palladium-catalyzed desulfitative Mizoroki-Heck couplings of sulfonyl chlorides with mono- and disubstituted olefins rhodium-catalyzed desulfitative Heck-type reactions under phosphine- and base-free conditions. Chem. Eur. J., 11, 2633-41. 

Dubbaka, S.R., Zhao, D., Fei, Z. et al. (2006) Palladium-catalyzed desulfitative Mizoroki-Heck coupling reactions of sulfonyl chlorides with olefins in a nitrile-functionalized ionic liquid. 

Dubbaka, S.R. and Vogel, P. (2005) Palladium-catalyzed desulfltative Mizoroki-Heck coupling of sulfonyl chlorides with mono- and disubstituted olefins rhodium-catalyzed desulfitative Heck-type reactions under phosphine- and base-free conditions. Chem. Eur. J., 11, 2633 1. Kamigata, N., Ozaki, J.-i., and Kobayashi, M. (1985) Reaction of alkenesulfonyl chlorides with olefins catalyzed by a ruthenium(ll) complex. A novel method for synthesis of ( , )- ,4-diaryl-... 

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