N,2,3,4-Tetrasubstituted Pyrrolidines through Tandem Lithium Amide Conjugate Addition/Radical Cyclization/Oxygenation Reactions

0463910 - ÚOCHB 2017 RIV DE eng J - Journal Article
Kafka, František - Pohl, Radek - Císařová, I. - Mackman, R. - Bahador, G. - Jahn, Ullrich
N,2,3,4-Tetrasubstituted Pyrrolidines through Tandem Lithium Amide Conjugate Addition/Radical Cyclization/Oxygenation Reactions.
European Journal of Organic Chemistry. Roč. 2016, č. 22 (2016), s. 3862-3871. ISSN 1434-193X. E-ISSN 1099-0690
R&D Projects: GA ČR GA13-40188S
Grant - others:COST(XE) CM1201
Institutional support: RVO:61388963
Keywords : tandem reactions * nitrogen heterocycles * Michael addition * radical reactions * cyclization * enolates
Subject RIV: CC - Organic Chemistry
Impact factor: 2.834, year: 2016

Enantioselective syntheses of densely functionalized pyrrolidines deriving their chirality from (R)-1-(phenyl) ethylamine are reported. Allylic amines and beta-substituted-alpha, beta-unsaturated esters are used as the building blocks in this one-pot reaction. Single electron transfer (SET) oxidation served to merge the reactivities of anionic enolate and radical intermediates. Ferrocenium hexafluorophosphate, which is easy to prepare, store and handle, was applied as SET oxidant and persistent free radical TEMPO served as the oxygenating agent introducing a protected hydroxy function, which proved to be beneficial for further derivatization. Exclusive 2,3-trans and up to 6: 1 3,4-cis/trans diastereoselectivities were achieved in the targeted tetrasubstituted pyrrolidines.
Permanent Link: http://hdl.handle.net/11104/0262991