Abstract The first example of monohydroboration of silylacetylenes with dichloroborane is described. The reaction occurs regio-and stereo-specifically and leads after methanolysis to isolable vinylboronic esters (III). The latter undergo photo Z⇌ E isomerization. Oxidation of III to the corresponding α-silaketone was accomplished in high yield using trimethylamine-N- oxide dihydrate. The overall method represents a useful conversion of acetylenes to α- ...
