Boron compounds haloboration

Boron trihalides, particularly BBr3, add to alkenes in a reaction (haloboration) that is usually more complicated than hydroboration.465 Several compounds can be isolated as a result of secondary transformation of the primary addition product 466... 

Recently haloboration reactions [49,50], boron polymers [51,52], phosphine-boron [53] and syntheses of intramolecularly coordinated five-membered ring compounds [54-60], etc., have been reported. 

As shown in Scheme 6, the polyaddition between 1,7-octadiyne and boron tribromide produced the corresponding poly(organoboron halide) as a brown solid without gelation. This polymer was soluble in common organic solvents such as chloroform. The structure of the polymer was supported by its iH-, llB-NMR, IR and UV spectra in comparison with those for the model compound prepared from boron tribromide and 1-hexyne. Table V summarizes the results of haloboration... 

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