2-(Trimethylsilyl)aryl 4-chlorobenzenesulfonates as efficient and versatile aryne precursors

Benzyne has been broadly employed in total syntheses of bioactive natural products and in preparations of functional materials. Accordingly, 2-(trimethylsilyl)aryl triflates have emerged as an important alternative for the formation of benzyne and derivatives under mild reaction conditions. In contrast to the advantages related with the application of silylaryl triflates in preparative organic chemistry, we can mention the use of trifluoromethanesulfonic anhydride, a volatile, corrosive, expensive, and relatively toxic liquid, in the synthesis of silylaryl triflates. In this context, we have developed a novel class of aryne precursors, namely, 2-(trimethylsilyl)aryl 4-chlorobenzenesulfonates, through a well-established sequence of reactions, aiming at the formation of arynes under relatively mild conditions, avoiding the use of trifluoromethanesulfonic anhydride. The applicability of 2-(trimethylsilyl)aryl 4-chlorobenzenesulfonates has been demonstrated via nucleophilic addition reactions leading to addition products in 24-92% yields and through different types of cycloadditions affording cycloadducts in yields up to 80%.