Selective CO Reduction in Phthalimide with Nickel(0) Compounds

The catalytic reduction of phthalimide was achieved using nickel catalysts. The use of catalytic amounts (20% mol) of [Ni­(COD)2] or [(dippe)­Ni­(μ-H)]2 (1) allowed the monoreduction of phthalimide to yield isoindolinone and benzamide, at 140–180 °C and 750 psi of H2. When the N–H moiety of phthalimide was protected with a trimethylsilyl group, both CO groups were reduced to yield (trimethylsilyl)­isoindoline. However, when a methyl moiety was used as the protecting group, the CO groups and the aromatic ring were reduced, using rather similar reaction conditions, due to the formation of 5 Å (average) nickel nanoparticles.