Recent advances in fluoride-free aryne generation from arene precursors

Aryne chemistry has experienced a remarkable renaissance in recent years, with a significant increase in the synthetic applications reported for these highly valuable reactive intermediates. This resurgence of interest is in part due to the introduction of ortho-silylaryl triflates as precursors which can be activated under mild conditions using fluoride. Alternative fluoride-free strategies have received interest in the last decade, with a number of precursors to arynes and their activators reported. These approaches offer alternative modes of reactivity which prove, in some cases, to be orthogonal to those of ortho-silylaryl triflates. This review highlights some of the more recent fluoride-free methodologies developed to access aryne intermediates that start from arene-based precursors.