Synthesis of (Z)-1-aryl-2-(germyl)-1-(stannyl)ethenes and the related ethenes, precursors to stereodefined germylethenes, via Pd(dba)2–P(OCH2)3CEt-catalyzed germastannation of acetylenes in THF

(Z)-1-Aryl-2-(germyl)-1-(stannyl)ethenes are synthesized in high yields by the addition of tributyl(triethylgermyl)stannane to arylacetylenes catalyzed by a specific combination catalyst, Pd(dba)2 and 4-ethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane, in tetrahydrofuran. Ethynylthiophene and 2-methyl-3-butyn-2-ol are also subject to the germastannation to afford the respective adducts in high yields. In addition, the JSn–H and 13C-NMR data for their adducts are presented.