Tungsten-catalyzed heterocycloisomerization approach to 4,5-dihydro-benzo[b]furans and -indoles.
A W(CO)(5)·THF-catalyzed cycloisomerization of bicyclo[4.1.0] substrates to afford mono C4-substituted 4,5-dihydro-benzo[b]furans and -indoles is reported. The title compounds are versatile intermediates that lead to a range of fused bicycles including the cores of various furan-, benzofuran-, and indole-containing natural products. In many cases, the functionalization of the dihydro-benzo[b]furans and -indoles is orthogonal to that of the corresponding benzofurans and indoles and, thus, offers complementary approaches for synthesis.
Department of Chemistry, University of California, Berkeley, California 94720, USA.
Ethan L
EL
Fisher
Sidney M
SM
Wilkerson-Hill
Richmond
R
Sarpong
D001572:Benzofurans / Q000138:chemical synthesis* / Q000737:chemistry; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D007536:Isomerism; D014414:Tungsten / Q000737:chemistry*
D001572:Benzofurans; D019086:Bridged Bicyclo Compounds, Heterocyclic; D007211:Indoles; D014414:Tungsten