Cyclic Diaryl λ <sup>3</sup> ‐Bromanes as a Precursor for Regiodivergent Alkynylation Reactions
Maxime De Abreu, Torben Rogge, Matteo Lanzi, Tomas J. Saiegh, K. N. Houk, Joanna Wencel‐Delord
Abstract
Regiodivergent reactions are a fascinating tool to rapidly access molecular diversity while using identical coupling partners. We have developed a new approach for regiodivergent synthesis using the dual character of hypervalent bromines. In addition to the recently reported reactivity of hypervalent bromines as aryne precursors, the first transition metal-catalyzed reaction is reported. Accordingly, the development of these two complementary transformations allows for the alteration of regioselectivity to furnish both ortho- and meta-substituted alkynylation products. Mechanistic and computational studies show how these selectivities are controlled.