Tandem Radical Cyclisation in the Flash Vacuum Pyrolysis of 2-Methoxyphenyl and 2-Methylthiophenyl Substituted Phosphorus Ylides
31 December 2000 (online)
The 2-alkynylphenoxy and -phenylthio radicals, conveniently generated by pyrolytic loss of Ph3PO and Me• from suitably substituted phosphorus ylides, undergo tandem cyclisation leading to tri- and tetracyclic fused benzofurans and benzothiophenes. The fundamental heterocyclic compound benzothieno[3,2-b]benzofuran has been prepared for the first time.
flash vacuum pyrolysis - phosphorus ylides - tandem cyclisation - fused heterocycles - benzothieno[3,2-b]benzofuran