Metal-free homo-/cross-anion-cation coupling of cyclic diaryl λ3-bromanes

The homo anion-cation coupling of cyclic diaryl lambda(3)-bromanes/diarylbrominiums, which was not reported in previous reports, has been disclosed for the first time. The competition experiments indicate that the anion-cation coupling follows the nucleophilic ability of the anions: the higher the nucleophilicity, the higher the reactivity. Moreover, metal-free cross-coupling of cyclic diarylbrominium tosylates with primary/secondary/tertiary/cyclic/linear/natural alcohols, phenols, water and their deuterated forms under mild conditions has been developed, giving meta-functionalized biaryl motifs in high yields with broad substrate scope. Preliminary mechanistic studies show that the nucleophilic agent is the major proton source in the cross-anion-cation coupling, which is affected by its concentration.

Automated summary

The homo anion-cation coupling of cyclic diaryl lambda(3)-bromanes/diarylbrominiums is reported for the first time, which has not been previously reported. Competition experiments indicate that the anion-cation coupling follows the nucleophilic ability of the anions, with higher nucleophilicity resulting in higher reactivity. Additionally, a metal-free cross-coupling reaction of cyclic diarylbrominium tosylates with various alcohols, phenols, water, and their deuterated forms has been developed under mild conditions, yielding meta-functionalized biaryl motifs in high yields with broad substrate scope. Preliminary mechanistic studies suggest that the nucleophilic agent is the main source of protons in the cross-anion-cation coupling, which is influenced by its concentration.