CO-transfer carbonylation reactions. A catalytic Pauson-Khand-type reaction of enynes with aldehydes as a source of carbon monoxide

The reaction of enynes with aldehydes in the presence of a catalytic amount of RhCl(cod)](2)/dppp results in the Pauson-Khand-type reaction without the use of gaseous carbon monoxide to give bicyclic cyclopentenones in high yields (14 examples). Aldehydes serve as a source of carbon monoxide, and their carbonyl moiety is transferred to enynes, resulting in the formation of the carbonylated products. This reaction represents the first example of a CO-transfer carbonylation.