Regioselective arene homologation through rhenium-catalyzed deoxygenative aromatization of 7-oxabicyclo[2.2.1]hepta-2,5-dienes
作者:Masahito Murai、Takuya Ogita、Kazuhiko Takai
DOI:10.1039/c9cc00270g
日期:——
Combined use of oxorhenium catalysts with triphenyl phosphite as an oxygen acceptor allowed efficient deoxygenative aromatization of oxabicyclic dienes. The reaction proceeded under neutral conditions and was compatible with various functional groups. Combining this deoxygenation with regioselective bromination and trapping of the generated aryne with furan resulted in benzannulative π-extension at
the presence of m-chloroperoxybenzoic acid to give substituted arenes as cycloadducts. Alternatively, thiophene S-oxides have been prepared by oxidation from thiophenes and have been subjected to cycloaddition with alkynes in a subsequent step. The outcome of the reaction is dependent on the steric demand of the thiophene S-oxide. Some thiophene S-oxides can be reacted at temperatures as high as 140°C