Organoborierung von alkinylstannanen : V. Zur reaktion von dialkyldi-1-propinylstannanen mit trialkylboranen

Treatment of R′₂Sn(CCCH₃)₂ (R′ = CH₃, C₂H₅) with BR₃ (R = CH₃, C₂H₅, i-C₃H₇) gives 1-bora-4stannacyclohexadienes and 2,5-bis(dialkylboryl)-1-stannacyclopent-3-enes. The formation of the heterocycles depends in a complex manner upon the ratio of the starting compounds, upon the nature of groups R and R′ and also upon the solvent. The proposed structures are discussed on the basis of ¹H, ¹¹B, ¹³C and ¹¹⁹Sn NMR data.