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

Abstract

The homo anion-cation of cyclic diaryl λ3-bromanes/diarylbrominiums, which was not reported in previous reports, has been disclosed for the first time. The competitive experiments indicates that the anion-cation coupling is...

Hydrazine–Halogen Exchange Strategy Toward N═N-Containing Compounds and Process Tracking for Mechanistic Insight

“…A heterocycle-fused cinnoline, thieno­[2,3- c ]­cinnoline 3q , was also synthesized but in low yield, which was due to the decomposition of iodonium. Except for cyclic iodoniums, rarely reported diaryl λ 3 -bromines also worked well, giving 3r – 3w in 24–78% yields.…”

Efficient synthesis of benzo[c]cinnolines and azoarenes via dual C–N coupling of phthalhydrazide and trivalent halogen reagents

“…14 a We also reported facile access to novel 1,1′-biisoquinolines, which are potential N , N -bidentate ligands. 14 b As part of our ongoing investigations on C–N bond formation and iodoniums, 14 herein, we disclose a hydrazyl–halogen exchange strategy for the formal synthesis of benzo[ c ]cinnolines and azobenzenes from phthalic hydrazide with trivalent cyclic 15 or linear 16 iodine( iii )/bromine( iii ) reagents (Scheme 1E). 3,3′,4,4′-Tetraphenyl-1,1′-biisoquinoline performs as a powerful ligand in tandem C–N coupling for the first time, delivering benzo[ c ]cinnolines with good yields and a broad scope.…”

meta-Selective O-Arylation of Cyclic Diaryliodonium Salts with Phenols via Aryne Intermediates

“…In 2021, Wencel-Delord reported the meta -esterification and amination of cyclic diaryl λ 3 -bromanes . During our preparation of this manuscript, Wencel-Delord further reported the meta-O -arylation of phenols involved with cyclic diaryl λ 3 -chloranes, and Li et al also reported a meta -selective cross-anion–cation coupling of cyclic diarylbrominium tosylates with alcohols and phenols . On the basis of our previous research about transition-metal-catalyzed ortho -functionalization of cyclic diaryl iodines, we are interested in further exploring the transition-metal-free meta -functionalization of cyclic diaryl iodines for the construction of 3-phenoxy-1,1′-biphenyl skeletons, which are prevalent in natural products and medicinal chemistry (Scheme c,d) …”

“…A plausible reaction pathway for this transformation was proposed on the basis of the present results and literature (Scheme ). , Initially, base-mediated deprotonation of 1a and 2a would furnish the phenolate A and benzyne intermediate B under heat, respectively. Next, the O -centered nucleophile would attack the benzyne intermediate B to form a new C–O bond, thereby resulting in the carbanion intermediate C .…”