C–O/C–S difunctionalized benzene derivatives via multicomponent coupling of tetraynes

Abstract

Csp2–O/Csp2–S difunctionalization of fused highly substituted benzene derivatives was conducted via the multicomponent coupling reaction of tetraynes, sulfoxides, and cyclopropenones. This reaction is associated with several bond cleavage and formation...

Recent Advances in Construction of C(sp2)–O Bonds via Aryne Participated Multicomponent Coupling Reactions

“…In an interesting extension in 2020, Hu and co-workers exploited sulfoxide insertion chemistry with HDDA-arynes and cyclopropenones (Scheme 20). 38 In the same way, the reaction proceeds via a [2+2] adduct and the resulting 1,4-zwitterionic sulfonium intermediate; tandem nucleophilic attack, ring opening, and proton abstraction with water delivers the multisubstituted arene. This process allowed the activation of cyclopropenones and introduced sulfide and phenol ester moieties into an aromatic ring in the absence of catalysts, bases, and oxidants.…”

Fully Substituted Conjugate Benzofuran Core: Multiyne Cascade Coupling and Oxidation of Cyclopropenone

“…Because of the ring strain, the intermediate IN3 exhibited ring opening to afford an o -quinone intermediate IN4 via TS3 . On the basis of previous reports, the zwitterion intermediate IN4 could be formed by a resonance structure of o -quinone intermediate IN4 . In the next step, the formation of a five-membered furan ring intermediate IN5 (unstable) was anticipated because of the participation of IN4 in the nucleophilic attack process via TS4 .…”

“…8 In particular, the thermal cycloisomerization of tethered multiynes to give benzyne intermediates has led to aryne chemistry becoming a blossoming area in recent years. 9 This so-called hexadehydro-Diels−Alder (HDDA) reaction, demonstrated by When tetrayne 1p and 2,3-diphenylcycloprop-2-enone 2a were initially investigated in our multicomponent coupling of tetrayne for the corresponding C−O/C−S difunctionalized benzene derivative synthesis, 13 to our delight, an unexpected fully substituted conjugate benzofuran 3p was obtained in 12% yield in DMSO under air. In contrast, when the reaction was performed under an Ar atmosphere, no product 3p was obtained.…”

“…When tetrayne 1p and 2,3-diphenylcycloprop-2-enone 2a were initially investigated in our multicomponent coupling of tetrayne for the corresponding C–O/C–S difunctionalized benzene derivative synthesis, to our delight, an unexpected fully substituted conjugate benzofuran 3p was obtained in 12% yield in DMSO under air. In contrast, when the reaction was performed under an Ar atmosphere, no product 3p was obtained.…”

Epoxyanthracene Derivatives and Dicarbonylation on Benzene Ring via Hexadehydro-Diels–Alder (HDDA) Derived Benzynes with Oxazoles

“…The low temperature is unfavorable to the occurrence of the retro-Diels-Alder reaction to make the nitrile compounds leaving. Previously our group once reported the cycloaddition reaction between HDDA-derived benzyne [17][18][19] and imidazole, and accidentally obtained isoindole 1,3-dione compounds. Considering the different reactivity between HDDA-derived benzyne and traditional benzyne, we investigated the reaction results of HDDA-derived benzyne with oxazole compounds here.…”