The hydroperoxide epoxidation of octene-1 and ethylallyl ethylacrylate, as well as the degradation of tert-butyl hydroperoxide, in chlorobenzene and toluene in the presence of d-metal borides as catalysts were studied. It was shown that molybdenum and vanadium borides exhibit the highest activity in this reaction. It was assumed that epoxidation proceeds via the primary formation of the catalyst-olefin complex.