SYNTHESES AND STRUCTURE OF DIBORYLACETYLE NES

Reactions of bis(trimethylstannyl)acetylene with 2-chloro-1,3,2-benzod ioxaborole derivatives or 9-chloro-9-borabicyclo[3.3.1]nonane lead to the corresponding diborylacetylenes 1a, b and 2. Sodium acetylide reac ts with R1R2BCl to give R1R2BC=CH (3a, b), which are converted to R1R2 BC=CBR1R2 (4a, b) by lithiation and subsequent treatment with more R1R 2BCl (R1 = iPr2N, R2 = iPr2N or tBu). X-Ray structure analyses are per formed for 1a, 4a, and 4b.