Thiophenes as Traps for Benzyne. 3. Diaryl Sulfides and the Role of Dipolar Intermediates

Autor:	Marcus Obeng, Dario Del Mazza, Manfred G. Reinecke
Rok vydání:	2002
Předmět:	chemistry.chemical_classification chemistry.chemical_compound Dipole chemistry Ylide Organic Chemistry Thiophene Photochemistry Medicinal chemistry Aryne Adduct
Zdroj:	The Journal of Organic Chemistry. 68:70-74
ISSN:	1520-6904 0022-3263
Popis:	The reactions of seven thiophenes with benzyne generated from diphenyliodonium-2-carboxylate (DPIC) under a standard set of conditions led among other products to the formation of alpha- and beta-naphthyl phenyl sulfides 2a and 2b from thiophene (1a) and of 2c and 2d from 2-methylthiophene (1b). Dithienyl sulfides 4a-f were produced from the halothiophenes 1c-g. The structures of the naphthyl sulfides were proven by comparison with authentic samples of 2a-f, thus eliminating one of two possible mechanisms of formation. The remaining mechanism involves [4+2]-cycloaddition of benzyne to thiophene or to an S-phenylthiophenium ylide 10 to give the dipolar 2:1 benzyne/thiophene adduct 8 followed by ring-opening. Stevens-like rearrangements of 11, formed from 10 by proton transfer, may also explain the origin of arylated thiophenes such as 12 and 3 found in some reactions of benzynes with thiophene.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7e724e6e120a8c30b506b5f22fdf2f6d https://doi.org/10.1021/jo0265176 Zobrazit plný text záznamu