Domino Reactions Initiated by Copper‐Catalyzed Aryl‐I Bond Thiolation For the Switchable Synthesis of 2,3‐Dihydrobenzothiazinones and Benzoisothiazolones

Abstract

The three-component reactions of o-iodobenzamides, elemental sulfur and dichloromethane (DCM) providing 2,3-dihydro-4H-benzo[e][1,3]thiazin-4-ones (2,3-dihydrobenzothiazinones) are accomplished via copper-catalyzed aryl CÀI thiolation and subsequent N-, S-hetero ring formation. In addition, the in situ aryl CÀI bond thiolation is also employed for the switchable synthesis of benzo[d]isothiazol-3(2H)ones (benzoisothiazolones) by subjecting o-iodobenzamides, elemental sulfur to the copper-catalyzed condition with microwave irradiation.

Recent Advances in the Synthesis of Heterocycles via Reactions Involving Elemental Sulfur

“…In general, Naryl products 134 a were obtained in higher yields than N-alkyl 134 b, which was tested for only one example. Similar reactivity was previously observed with ochlorobenzamidines [107] and o-bromobenzamides [108] (See section 2.8).…”

“…When benzamides [108] were used in place of benzamidines, Liu et al found that o-iodo derivatives 247 were particularly reactive for a similar transformation, especially in the presence of CuBr 2 as a catalyst (Scheme 86). The expected benzoisothiazole products 248 could be formed for less than 10 min upon microwave irradiation with sulfur and triethylamine.…”

“…Using copper/1,10-phenanthroline catalyst, the reaction consisted in a first step of thiolation of aromatic CÀ I bond and subsequent reaction with CH 2 Cl 2 . [108] A four-component reaction of acetophenone with two molecules of anilines and sulfur leading to 2Hbenzo [b] [1,4]thiazin-2-imine 281 was reported (Scheme 97). [126] This transformation was based on the o-sulfuration of anilines at high temperature with elemental sulfur to provide o,o'-diamino diphenyl oligo sulfides, which was previously described.…”

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 average molecular weight of the copolymer was studied by GPC analysis. 6,21 According to the GPC results, the average molecular weight of compound 4 was found to be 12 580. Table 1 shows the results of the EDX elemental analysis and GPC for all the prepared compounds.…”

“…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.…”