Pictet–Spengler/Palladium Catalyzed Allenylation and Carbonylation Processes

The tactical combination of the Pictet–Spengler reaction with Pd catalyzed reactions with allene and with carbon monoxide provides rapid access to a range of tetrahydro-β-carboline and tetrahydroisoquinoline derivatives via intramolecular trapping of intermediate π-allyl– and acyl–palladium(II) complexes by the indolic or secondary amino moieties generating fused azepine and δ-lactam derivatives. Chiral tryptophan examples are also described.