A Three‐Component Reaction of Aryldiazonium Tetrafluoroborates, Sulfur Dioxide, and 1‐(Prop‐2‐yn‐1‐yl)indoles under Catalyst‐Free Conditions

Abstract

No Abstract

Metal- and base-free tandem sulfonylation/cyclization of 1,5-dienes with aryldiazonium salts via the insertion of sulfur dioxide

“… 7 The incorporation of sulfonyl group into heterocycles by radical cascade cyclization reactions has aroused extensive interest among scientists. 8 In recent years, many sulfone-containing heterocyclic frameworks have been constructed by radical cascade cyclization reactions, such as sulfonylindoles, 9 sulfonylindolins, 10 sulfonylated pyrrolidines, 11 sulfonylated phenanthridines, 12 sulfonylated benzofurans, 13 sulfonated oxazolines, 14 sulfonylated spirocycles 15 and others. 16 In 2021, sulfonylated pyrrolinones were synthesized via sulfonylation/cyclization of 1,5-dienes with sulfonyl chlorides or sodium sulfinates by Wang and co-workers ( Fig.…”

Recent Development of Aryl Diazonium Chemistry for the Derivatization of Aromatic Compounds

“…This radical cyclization process with the insertion of SO 2 has also been utilized in synthesizing sulfonated five-membered rings, including 3-sulfonated-2,3-dihydrobenzo­[ d ]­isothiazole 1,1-dioxides 280 , sulfonated 9 H -pyrrolo­[1,2- a ]­indoles 282 , and azaspiro­[4,5]-decanes 285 and azaspiro­[4,5]-trienones 286 under transition-metal- and photoredox-free conditions (Scheme ).…”

“…362 reaction proceeds via the addition of in situ generated aryl sulfonyl radical 247 to vinyl azides along with the extrusion of N 2 , followed by intramolecular cyclization, single-electron oxidation, and deprotonation to obtain 6-(sulfonylmethyl)phenanthridine scaffold. This radical cyclization process with the insertion of SO 2 has also been utilized in synthesizing sulfonated five-membered 364 and azaspiro [4,5]-decanes 285 and azaspiro [4,5]trienones 286 365 under transition-metal-and photoredox-free conditions (Scheme 203).…”

Photoredox-Catalyzed Hydrosulfonylation of Arylallenes

“…The synthesis of sulfones is a needful task, with numerous methods developed . In general, the preparation of vinyl sulfones relies on sulfonylation of alkenes through oxidative or cross-coupling reactions, decarboxylative couplings with alkenes or alkynes, tosylhydrazone decompositions, SO 2 fixation approaches, or hydrosulfonylation of alkynes . The metal-free synthesis of sulfones is also realizable from sulfonate esters .…”