Construction of Eight-Membered Cyclic Diaryl Sulfides via Domino Reaction of Arynes with Thioaurone Analogues and DFT Study on the Reaction Mechanism

Abstract

Eight-membered cyclic and [5,5]-bicyclic sulfides were synthesized via a domino reaction between thioaurone analogues and arynes. Density functional theory calculations were performed to elucidate the reaction mechanism, which involves the elementary steps of the [3 + 2] cycloaddition, 1,2-hydrogen shift, and C­(sp2)–S bond cleavage as well as the substituent effect.

Access to Spirocyclic Benzothiophenones with Multiple Stereocenters via an Organocatalytic Cascade Reaction

“…Other valuable protocols for the synthesis of enantiomerically enriched, sulfur-bearing full-substituted carbon stereocenters include Mannich reactions of thiols into ketimines and electrophilic sulfenylation reactions of α-branched aldehydes, β-keto esters, nitroacetates, oxindols, benzofuran-2­(3 H )-ones, and oxazolones. , An alternative organocatalytic strategy for the preparation of such enantiomerically enriched compounds containing a sulfur-bearing full-substituted stereogenic center is based on the stereoselective formation of C–C or C–N bonds using prochiral sulfur-based substrates, such as α-sulfenylated acrylates and enals, rhodanines, 3-thiooxindoles, and thiazolones. , Yet, only a few reports on organocatalytic reactions on benzo­[ b ]­thiophene derivatives have been published to date . Considering the above and our interest in the enantioselective preparation of heterocycles with a full-substituted stereogenic center bearing a sulfur atom, we aimed to use an enantioselective double-Michael-cascade reaction of benzo­[ b ]­thiophenone derivatives with less reactive enones, based on in situ generation of 2-aminobuta-1,3-diene intermediates …”

o-Silylaryl Triflates: A Journey of Kobayashi Aryne Precursors

“…Consequently, a proton transfer with a following β-elimination could furnish products 9-57 ; whereas, in the cases of α-ester- and α-acyl-substituted vinyl sulfides (R 1 = COR′) 9-56 , a successive C-arylation/1,4-proton transfer/β-elimination process occurred to yield products 9-58 . A similar transformation was then independently reported by the groups of Yu/Zhang/Meng and Li/Chen, in which 2-methylenebenzothiophene-3-ones 9-60 reacted with arynes to furnish eight-membered cyclic sulfides 9-61 (Scheme b). The mechanism for this transformation involves a tandem [3 + 2] cycloaddition reaction/1,2-proton transfer/C–S bond cleavage process.…”

Ni/Pd-catalyzed Suzuki–Miyaura cross-coupling of alcohols and aldehydes and C–N cross-coupling of nitro and aminesviadomino redox reactions: base-free, hydride acceptor-free

“…The construction of eight-membered cyclic diaryl suldes via the domino reaction of arynes with thioaurone analogues, 4 toluene oxidation-Knoevenagel-condensation domino reaction, 5 Cu-catalyzed aryl-I bond thiolation for the switchable synthesis of 2,3-dihydrobenzothiazinones and benzoisothiazolones, 6 Cu-catalyzed one-pot synthesis of C-4 sulfonated isoquinolin-1(2H)-ones, 7 and Co-catalyzed diastereoselective diuoroalkylation/Giese addition domino reactions 8 are some of the recently reported applications of the domino approach in organic synthesis. Previously, Chandra et al reviewed the application of domino reactions in catalytic C-C bond formation.…”