Denis D Borisov, Irina A Borisova, Mikhail R Antanyazov, Ilya V Prolomov, Michael G Medvedev, Roman A Novikov, Yury V Tomilov
The unprecedented C(sp2)-H functionalization of ethylidenemalonate with internal alkynes was discovered, leading to substituted vinylcyclopentanes as trans,trans-isomers (dr > 15 : 1). The experiment with deuterated ethylidenemalonate showed that the formation of substituted vinylcyclopentane is accompanied by a 1,2-hydride shift and mono-γ-C-H insertion into the internal alkyne.