Palladium-Catalyzed, Enantioselective Desymmetrization of N-Acylaziridines with Indoles

Abstract

Ring opening reactions of meso-aziridines generate chiral amine derivatives where the control of stereochemistry is possible through enantioselective catalysis. We report the use of a diphosphine–palladium­(II) catalyst for the highly enantioselective desymmetrization of N-acylaziridines with indoles. The β-tryptamine products are isolated in moderate to high yield across a range of indole and aziridine substitution patterns. The synthetic utility of β-tryptamine products is demonstrated by conversion to the brominated pyrroloindoline derivative.

Palladium-catalysed enantio- and regioselective (3 + 2) cycloaddition reactions of sulfamidate imine-derived 1-azadienes towards spirocyclic cyclopentanes

“…3). 61,62 Ionisation of the racemic VCP by the chiral [(S)-DM-Segphos]Pd 0 complex can afford either diastereomeric complex A or B, which can interconvert via p-s-p isomerisation. Of these two, complex A is likely more favoured due to the lower steric interaction between the dipole fragment and the equatorial xylyl group from the ligand.…”

Merging Ring-Opening 1,2-Metallate Shift with Asymmetric C(sp3)–H Borylation of Aziridines

“…In particular, the asymmetric ring opening of aziridines has received considerable interest . In this context, desymmetrization of meso -aziridines − or the (dynamic) kinetic resolution of racemic-aziridines usually provides efficient ways to chiral secondary alkyl amines with a vicinal tertiary stereocenter (Scheme A). Owing to the ring strain of aziridines, another attractive approach is ring-opening 1,2-rearrangement.…”