Platinum-Catalyzed Diastereoselective Intramolecular Coupling of Allyl Halides and Hydrazones

Nucleophilic allyl platinum addition to hydrazones under platinum-catalyzed conditions was studied. To generate nucleophilic allyl platinum complexes, allyl halides were employed with platinum complexes, SnCl₂, and H₂. The allyl platinum(IV) intermediates reacted with the hydrazone to give the corresponding cyclic amine derivatives in good yield and with excellent diastereoselectivity. The cis selectivity of N-tethered substrates was attributed to a tight interaction of allyl platinum species with the hydrazone, on the basis of the results of solvent screening and acid/base addition experiments.