ROM-RCM of cycloalkene-yne

Abstract

Ring-opening metathesis and ring-closing metathesis (ROM-RCM) of cycloalkene-yne was demonstrated using a first- or second-generation ruthenium complex. When cycloalkenes bearing the alkyne part at the C-3 position were reacted with a first-generation ruthenium–carbene complex under an atmosphere of ethylene, ROM-RCM proceeded smoothly to give skeletal reorganized products in good yields. In this reaction, cycloalkene-ynes having terminal alkyne were suitable. On the other hand, when cycloalkenes bearing the alkyne part at the C-1 position were treated with a second-generation ruthenium–carbene complex, ROM-RCM proceeded smoothly to give bicyclic compounds and/or dimeric compounds in good yields.