Rapid access to arynes from aryl triflates using a non-competitive, commercially available amide base

Abstract

Arynes are novel intermediates for organic synthesis and aryl triflates are potentially useful aryne precursors because they are commercially available or easily prepared from widely abundant phenols. However, strong bases, which are also competitive arynophiles, are often used to generate arynes from aryl triflates and this can limit their use in synthesis. We have found that the commercially available lithium bis(trimethylsilyl)amide is uniquely non-competitive among this class of base in generating arynes from aryl triflates. We demonstrate that this method is compatible with 15 aryl triflates and 6 different arynophiles in yields ranging from 54 to 96 % (75 % avg). Moreover, we parameterize several common bases used to generate arynes from aryl triflates on an arynophilicity scale, and we describe the overall robustness of this process relative to other aryne forming reactions.