Palladium catalysis sulfone synthesis

A tandem Suzuki-Miyaura coupling/nucleophilic aromatic substitution to carba-zoles was developed by St. Jean et al. (Scheme 51) [210]. Reaction of A -sulfonyl-protected 2-aminophenylboronates 216 with l-bromo-2-fluorobenzenes 217 under palladium(0)-catalysis provides the Af-sulfonyl-protected carbazoles 218. This annulation is compatible with a variety of electron-withdrawing groups (e.g., aldehydes, esters, and sulfones) and has been applied to an efficient synthesis of glycosinine (147) (four steps, 50% overall yield). 

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