Electrochemical Selenylative Carbannulation of Biaryl Ynones to Seleno-Dibenzocycloheptenones/Spiro[5.5]Trienones

Abstract

Electrooxidative-induced synthesis of structurally diverse seleno-dibenzocyclohepten-5-ones and seleno-spiro[5.5]trienones by selenylative carbannulation of biaryl ynones with diaryl diselenide has been developed. The switchable reactivity, intramolecular ortho-annulation or dearomative ipso-annulation, is directed by the substituent present on the ortho-aryl group of arylynone. The prominent features of this method include metal-free, external chemical oxidant-free conditions, and readily accessible substrates.Article pubs.acs.org/joc

Nitro-Spirocyclization of Biaryl Ynones with tert-Butyl Nitrite: Access to NO2-Substituted Spiro[5,5]trienones

“…The detailed protocol for preparation of biaryl ynones was according to references , , and , respectively.…”

“…Consequently, several efficient oxidative/nucleophilic/electrophilic dearomatization and transition-metal or radical-promoted dearomatization processes have been accomplished by many groups so far. − As known, the radical cascade 5- exo -trig and 6- exo -trig spirocyclization of alkynes to access spirocycles have become active areas of research recently. − ,, Among them, many groups respectively developed excellent strategies for the synthesis of spiro­[5,5]­trienones by using biaryl ynones as the starting materials. ,, Recently, our group reported a photoinduced spirocyclization reaction to give SCN-featured spiro­[5,5]­trienones . Despite this advanced work, there is still a fundamental need to find some easy operations and good regioselectivity systems to gain spiro­[5,5]­trienones.…”

Electrochemical electrophilic bromination/spirocyclization of N-benzyl-acrylamides to brominated 2-azaspiro[4.5]decanes

“…8 Recently, electrochemical dearomatizing spirocyclization could be achieved for the synthesis of spiro compounds under oxidant-free conditions. 9 Guo and coworkers described an electrochemical selenation/spirocyclization of N -aryl alkynamides to give selenated 1-azaspiro[4.5]trienones. 10 Chen and Xu developed an electrochemical oxidative halospirocyclization of N -aryl alkynamides to synthesize 1-azaspiro[4.5]trienones.…”

Electrochemical Dearomative Spirocyclization

“…For instance, The Chen group employed the readily available lithium halides as the halogen radical precursors for the electrochemical dearomative spirocyclization of N ‐arynylamides 54 [39] . Reddy and co‐colleagues reported an electrochemical spirocyclization of diarylenones 55 with diaryldiselenides to access diverse seleno‐spiro[5.5]trienones 57 [40] . Langlois’ agent (NaSO 2 CF 3 ), NaSO 2 CF 2 H, [41] AgSCF 3 [42] have been all successfully incorporated in such a kind of transformation to provide value‐added fluorinated spirocycles ( 58 and 59 ).…”