Cyclic Diaryl λ3‐Bromanes as Original Aryne Precursors. Issue 27 (26th May 2021)

• Record Type: Journal Article
• Authors: Lanzi, Matteo; Dherbassy, Quentin; Wencel‐Delord, Joanna
• Is Part Of: Angewandte Chemie international edition. Volume 60:Issue 27(2021)
• Page Start: 14852
• Page End: 14857
• Publication Date: 2021-05-26
• Subjects: arynes -- hypervalent bromine -- hypervalent iodine -- metal-free coupling -- λ3-bromanes; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202103625
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Despite the widespread application of hypervalent iodines, the corresponding λ 3 ‐bromanes are less explored. Herein we report a general, safe, and high‐yielding strategy to access cyclic diaryl λ 3 ‐bromanes. These unique compounds feature reactivity that is appealing and complementary to that of λ 3 ‐iodanes, generating arynes under mild reaction conditions and in the presence of a weak base. Accordingly, formal meta ‐selective transition‐metal‐free C–O and C–N couplings may be achieved. Mechanistic studies unambiguously support the aryne generation mechanism. Abstract : Diaryl λ 3 ‐bromanes are rare and unexplored hypervalent compounds. An efficient and mild protocol affords now a large panel of these hypervalent compounds, featuring reactivity complementary to that of the corresponding diaryl λ 3 ‐iodanes. Due to their high reactivity, metal‐free meta ‐selective C–O and C–N coupling occurs through in situ aryne generation.