B-Vinylborazine or 2-Ethenylborazine

Although vinyl derivatives of alkylated borazines have been known for some time, the methods used for their syntheses cannot be used for the parent B-vinylborazine because of extensive side reactions. The transition metal catalyzed synthetic route described below gives B-alkenylborazines in high yields.  

Since the pressure in the reaction vessel could initially exceed one atmosphere, a suitable pressure reactor must be used. 

Borazine is prepared by the procedure described above. Impurities in commercially obtained acetylene can result in the precipitation of the catalyst, and in such cases, no reaction is observed. Acetylene is therefore purified by a process similar to that described in the literaturein which acetone and other impurities are removed by a purification train consisting of two bubblers of concentrated sulfuric acid followed by two U-traps containing NaOH pellets and white Drierite, respectively, to remove moisture. The inlet of the train is connected to a cyhnder of acetylene, and its outlet to the vacuum line. 

The catalyst is still active upon removal of the products and can be used repeatedly with no signs of decreased yields or turnover rates. 

B-Vinylborazine is an air-sensitive volatile hquid and is soluble in dry aprotic organic solvents. It decomposes rapidly in contact with water and alcohols. 

Main Group and Transition Metal Cluster Compounds 

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