A new catalytic cyclization of o-alkynylbenzaldehyde acetals 1 to the functionalized indenes 2 was found to be strictly controlled by the number of triphenylphosphine ligands on the Pd catalyst. Only complexes with three available coordination sites on Pd catalyze this reaction. Mechanistic study suggests that π-coordination of Pd to the benzene ring is a key step controlled by the number of vacant coordination sites.
ASJC Scopus subject areas
- Colloid and Surface Chemistry