MIGRATION OF GROUPS FROM ZIRCONIUM TO BORON - ASPECTS OF SYNTHESIS AND UTILITY

The hydrozirconation of alkenes or alkynes yields the dicyclopentadien yl alkyl- or alkenylzirconium chloride, respectively, in high yields a nd with high regioselectivity. The reaction of these organozirconium c ompounds with a boron halide results in the exchange of the halogen an d organic group, forming the organoborane. We report here a systematic investigation of the transmetallation of organic groups from zirconiu m to a variety of boron compounds. The migration is facile to a variet y of boron halides, yielding structurally different types of alkyl or alkenylboranes in good to high yields Exploiting the unique reactivity and selectivity of the hydrozirconation reaction for the preparation of organoboranes expands the range of potential of both metals for syn thesis.