RSS-Feed abonnieren
DOI: 10.1055/s-0030-1258019
Thiophenol-Mediated Radical Cyclizations
Publikationsverlauf
Publikationsdatum:
13. August 2010 (online)
Introduction
Thiophenol (PhSH, CAS: 108-98-5-Y) is a commercially available organosulfur compound. Recently thiophenol-mediated radical cyclizations become highlighted for the construction of heterocycles due to the cost-effective, tin-free methodology. These radical reactions proceed via the formation of a carbon-centered radical species generated by the addition of a sulfanyl radical to an unsaturated bond and a subsequent intramolecular addition of the resulting carbon-centered radical to another multiple bond, followed by the abstraction of hydrogen from thiophenol to afford the product (Scheme [¹] a). Otherwise, the sulfanyl radical, generated from thiophenol and radical initiator, adds to the terminus of the triple bond to generate an alkenyl radical, which undergoes a 1,5-hydrogen atom transfer (HAT). After translocation, the new radical species can cyclize intramolecularly to give a cyclopentane derivative (Scheme [¹] b).
Scheme 1
- 1
Fernandez M.Alonso R. Org. Lett. 2005, 7: 11 - 2
Majumdar KC.Debnath P.Maji PK. Tetrahedron Lett. 2007, 48: 5265 - 3
O’Neill PM.Mukhtar A.Ward SA.Bickley JF.Davies J.Bachi MD.Stocks PA. Org. Lett. 2004, 6: 3035 - 4
Majumdar KC.Mondal S.Ghosh D. Tetrahedron Lett. 2010, 51: 348 - 5
Pedrosa R.Andres C.Duque-Soladana JP.Maestro A.Nieto J. Tetrahedron: Asymmetry 2003, 14: 2985 - 6
Majumdar KC.Debnath P.Alam S.Maji PK. Tetrahedron Lett. 2007, 48: 7031 - 7
Carta P.Puljic N.Robert C.Dhimane AL.Fensterbank L.Lacôte E.Malacria M. Org. Lett. 2007, 9: 1061 - 8
Miyata O.Namba M.Ueda M.Naito T. Org. Biomol. Chem. 2004, 2: 1274 - 9
Friestad GK.Massari SE. Org. Lett. 2000, 2: 4237