1,1-Carboboration of alkynylgermanes – New germoles

Abstract The C≡C bonds of various alkynylgermanes [Cl(H)Ge(C≡C–R 1 ) 2 , Cl 2 Ge(C≡C–R 1 ) 2 with R 1  =  n Bu, SiMe 3 , and Ge(C≡C–R 1 ) 4 with R 1  = SiMe 3 ] undergo 1,1-carboboration when treated with an excess of triethylborane at 80–110 °C. All pure final products with R 1  = SiMe 3 possess germole-derived structures. Intermediates and side products as a result of lost stereoselectivity of the 1,1-carboborations could be detected and in some cases identified by NMR spectroscopic studies of the reaction solutions.