The Amination and Dimerization of Norbornadiene with Nickel, Palladium, and Rhodium Complexes

The reactions of norbornadiene in amine by the use of nickel, palladium and rhodium complexes have been studied in the presence of protic acid. A catalytic system of Ni(COD)2 (1)-n-Bu3P gives a mixture of 5-exo-(o-tolyl)-2-norbornene (3) and 5-exo-(N-amino)-2-norbornene (4). Bis(triphenylphosphine)(maleic anhydride)palladium (5) gives 3-(N-amino)nortricyclene (6). Dichlorotetrakis(cyclooctene)dirhodium (10) gives a [2+4] cycloaddition product (11). All these reactions mechanisms are discussed from the point of view of an acid-promoted reaction on low-valent transition metal complexes.