Organoboron compounds. Part VI. Photochemical reactions of aryl and alkyl halides with boron halides
The photolysis of aryl iodides in the presence of boron halides results in the formation of arylboron dihalides and diarylboron halides by free-radical substitution reactions. Hydrolysis of the products gives the corresponding boronic and borinic acids. Alkyl iodides and di-iodo-compounds behave in a similar manner. The photolysis and subsequent hydrolysis of mixtures of bromo- or chloro-benzene with boron tribromide also affords boronic acids; the by-products indicate that the dibromoboryl (Br2B·) radical takes part in these reactions.