Meta-OTf-Substituted Diaryliodonium Salts Enabled Diels-Alder Cycloadditions of Furans via Aryne Intermediates

Arynes are highly reactive intermediates that may be trapped with arynophilic reagents. However, the generation of benzyne necessitates stringent reaction conditions. The cycloaddition reaction of traditional benzyne precursors including diaryliodonium salts with arynophiles under strongly basic conditions encounters the limitations in tolerance of labile functional groups. To overcome this issue, the modulation of diaryliodonium structures are considered by incorporation of specific groups for activation of vinical C-H bond, enabling the generation of aryne intermediates in cycloaddition reactions under mild conditions. In this study, we reported meta-trifluoromethanesulfonate (OTf) substituted diaryliodonium salts as benzyne precursor, in which the activation of C-I bond and selectively deprotonation of neighboring C-H bond generate highly reactive aryne intermediates for cycloaddition reactions with furans. This approach offers a simple and efficient method for synthesizing bridged ring compounds under mild reaction conditions with good functional group tolerance.