An efficient and chemoselective method to generate arynes.

Arynes hold immense potential as reactive intermediates in organic synthesis as they engage in a diverse range of mechanistically distinct chemical reactions. However, the poor functional group compatibility of generating arynes or their precursors has stymied their widespread use. Here, we show that generating arynes by deprotonation of an arene and elimination of an "onium" leaving group is mild, efficient and broad in scope.

Oxidative Cycloaddition Reactions of Arylboron Reagents via a One-pot Formal Dehydroboration Sequence.

Arylboron compounds are widely available and synthetically useful reagents in which the boron group is typically substituted. Herein, we show that the boron group and -hydrogen atom are substituted in a formal cycloaddition reaction. This transformation is enabled by a one-pot sequence involving diaryliodonium and aryne intermediates.

The Direct Conversion of Esters to Ketones Enabled by a Traceless Activating Group.

We report here the design and development of a method for the single-step conversion of esters to ketones with simple reagents. The selective transformation of esters to ketones, rather than tertiary alcohols, is made possible by the use of a transient sulfinate group on the nucleophile that activates the adjacent carbon toward deprotonation to form a carbanion that adds to the ester, followed by a second deprotonation to prevent further addition. The resulting dianion undergoes spontaneous fragmentation of the SO group upon quenching with water to reveal the ketone product.

Synthesis of Arynes via Formal Dehydrogenation of Arenes.

Arynes offer immense potential for diversification of benzenoid rings, which occur in pharmaceuticals, agrochemicals, and liquid crystals. However, accessing these high-energy intermediates requires synthetic precursors, which involve either harsh conditions or multistep syntheses. The development of alternative methods to access arynes using simpler substrates and milder conditions is necessary for a more streamlined approach.