Nickel-catalyzed three-component [3+2+2] cocyclization of ethyl cyclopropylideneacetate and alkynes - Selective synthesis of multisubstituted cycloheptadienes

Abstract

(Chemical Equation Presented) Ménage à trois: Seven-membered carbocycles are formed by the three-component [3+2+2] cycloaddition of ethyl cyclopropylideneacetate and two different alkynes in the presence of a Ni 0/PPh3 catalyst (see scheme). In this one-pot reaction, a highly chemo- and regioselective coupling proceeds, and the cycloheptadiene derivatives are isolated as single isomers. © 2006 Wiley-VCH Verlag GmbH & Co. KGaA.