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.