Attached
Novel metal complexed ind~ced r~actioni of azirines provide
simple and convenient synthetic approaches to heterocyclic
systems. Palladium (0) catalyzed carbonylation reactions
of azirines under homogeneous and heterogeneous reaction
conditions, as well as molybdenum hexacarbonyl induced
reactions of azirines in the presence of carbanions are
described. Various reagents and conditions employed for
carrying out these different reactions are presented in
three sections.
The use of soluble pallad~um (0) catalysts for
the carbonylation of azirines results in the novel syntheses
of two important classes of compounds. The reaction course
is dependent on the nature of the ligands attached to the
metal. Tetrakis(triphenylphosphine)palladium (0) catalyzes
the conversion of azirines to S -lactams, while vinyl
isocyanates are formed in a regiospecific reaction using
bis(dibenzylideneacetone)palladium (0) as the catalyst.
A mechanism is proposed for these reactions.
2-Styrylindoles were obtained in modest yields
by the exposure of azirines to carbon monoxide, a palladium
(0) catalyst, sodium hydroxide, benzene as the organic
phase and benzyltriethylammonium chloride as the phase
transfer agent. The reaction is sensitive to the atmosphere
used.
