title: A radical cascade cyclization to prepare dihydrothiophenes induced by thiyl radicals as sulfur biradical equivalents.
abstract: Bicyclic dihydrothiophenes are readily prepared by a radical cascade cyclization reaction triggered by the addition of a thiyl radical under thermal or photoirradiation conditions. The translocated radical attacks the sulfur atom in the initial radical donor unit in an SHi manner. Sufficient stereoselectivity is achieved when a large excess of disulfide is used for the reaction under photoirradiation conditions. The reaction in the absence of solvents provides vinylsulfides instead of dihydrothiophenes. Thus, the sulfur atom in the thiyl radical serves as a sulfur biradical synthetic equivalent.
authors.affiliation: Department of Applied Molecular Science, Graduate School of Medicine, Yamaguchi University, Ube 755-8611, Japan. ak10@yamaguchi-u.ac.jp
authors.forename: Akio
authors.initials: A
authors.lastname: Kamimura
authors.forename: Koichiro
authors.initials: K
authors.lastname: Miyazaki
authors.forename: Yu
authors.initials: Y
authors.lastname: Yamane
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Yo
authors.forename: Shingo
authors.initials: S
authors.lastname: Ishikawa
authors.forename: Hidemitsu
authors.initials: H
authors.lastname: Uno
authors.forename: Michinori
authors.initials: M
authors.lastname: Sumimoto
mesh_terms: D003500:Cyclization; D005609:Free Radicals / Q000138:chemical synthesis / Q000737:chemistry; D015394:Molecular Structure; D013455:Sulfur / Q000737:chemistry*; D013876:Thiophenes / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D005609:Free Radicals; D013876:Thiophenes; D013455:Sulfur