We have investigated new routes to enantiomerically pure ferrocene-based Lewis We have investigated new routes to enantiomerically pure ferrocene-based Lewis acids. Different organometallic precursors were prepared and their utility in acids. Different organometallic precursors were prepared and their utility in transmetallation reactions was examined. We found the ferrocenylmercury derivative transmetallation reactions was examined. We found the ferrocenylmercury derivative to give by far the best selectivity and highest yields.to give by far the best selectivity and highest yields.

M = SnMe3, HgCl, Cu

FeM

BX2 = BCl2, B(C6F5)2

FeBX2

The highly Lewis acidic chiral organoborane 1-naphthyl-2-bis(pentafluorophenyl)borane was obtained in high yield by treatment of the chloroborane with the mild reagent CuC6F5. Studies on applications of this unusual Lewis acid in catalysis are under way.

Lewis Acid Chemistry at the Edge of FerroceneLewis Acid Chemistry at the Edge of Ferrocene

Frieder Jäkle, Department of Chemistry Rutgers University, Newark, NJ 07102