We developed a concise protocol for the synthesis of ellipticine quinone from the appropriate 3-iodoindole-2-carbaldehydes in four steps. The key step is the construction of carbazole-1,4-quinone through tandem Ring-Closing Metathesis (RCM) and dehydrogenation under oxygen atmosphere. Therefore, the ellipticine quinone analogs possessing substitution at the 8- and/or 9-positions were synthesized using
Iron-Promoted Cyclization/Halogenation of Alkynyl Diethyl Acetals
作者:Tongyu Xu、Zhengkun Yu、Liandi Wang
DOI:10.1021/ol9005689
日期:2009.5.21
FeCl3- and FeBr3-promoted cyclization/halogenation of alkynyl diethyl acetals has been efficiently realized, selectively affording (E)-2-(1-halobenzylidene or alkylidene)-substituted five-membered carbo- and heterocycles which were then efficiently transformed to vinylarenes by Suzuki coupling. The present protocol has provided a new alternative route to vinylic C−Cl and C−Br bond formation.