Benzosultam synthesis exploiting sequential palladium-catalysed intermolecular aminosulfonylation and intramolecular sulfamidation

We report a route to benzosultams that exploits the palladium-catalysed aminsulfonylation of alkenyl iodides as the initial step. An (Z)-configured alkenyl iodide substrate is combined with DABSO, a N,N-dialkylhydrazine nucleophile and a palladium(0) catalyst to achieve aminsulfonylation. A second palladium(0)-catalysed transformation, this time intramolecular, leads to benzosultam formation. Good variation of the starting alkenyl iodides is possible. A related SNAr route was also explored, but was shown to be less efficient. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

A synthetic route to benzosultams was reported, using palladium-catalysed aminsulfonylation of alkenyl iodides as the initial step, followed by an intramolecular transformation to form benzosultams. The method allows for good variation of starting alkenyl iodides and was shown to be more efficient than a related SNAr route.