Three isomeric o-fluoronaphthaldehydes, 9-fluorophenanthrene, and three previously unreported o-fluorophenanthrene aldehydes were analyzed in detail by multiple NMR techniques to provide unambiguous assignment of structures and resonances. The six aldehydes serve as the key starting materials for novel chiral ligands used in highly enantioselective rhodium-catalyzed asymmetric hydrogenation reactions.
Copyright 2009 John Wiley & Sons, Ltd.