Scheme 4. Selective synthesis of pyrroloindoline 9d. Bimolecular Pd0-catalyzed C3-selective cinnamylation of 5-fluoro-l-tryptophan promoted by Et3B sets up to form the bridging 15-membered ring by lactamization. 1H NMR spectra (500 MHz, DMSO-d6) of 9d obtained by this route match that of material isolated from the acid-promoted cyclization. Key resonance annotations in blue. * Denotes contaminant signals.
