N,3,4-Trisubstituted pyrrolidines by electron transfer-induced oxidative cyclizations of N-allylic beta-amino ester enolates

0332983 - ÚOCHB 2010 RIV GB eng J - Článek v odborném periodiku
Jahn, Ullrich - Kafka, František - Pohl, Radek - Jones, P.G.
N,3,4-Trisubstituted pyrrolidines by electron transfer-induced oxidative cyclizations of N-allylic beta-amino ester enolates.
Tetrahedron. Roč. 65, č. 52 (2009), s. 10917-10929. ISSN 0040-4020. E-ISSN 1464-5416
Výzkumný záměr: CEZ:AV0Z40550506
Klíčová slova: electron transfer * pyrrolidines * oxidation
Kód oboru RIV: CC - Organická chemie
Impakt faktor: 3.219, rok: 2009

Oxidative radical cyclizations starting from easily accessible N-allylic beta-alanine esters are reported. Deprotonation generates the corresponding enolates, which are transformed efficiently into alpha-ester radicals by single electron transfer mediated by ferrocenium hexafluorophosphate. The stereochemistry of the radical 5-exo cyclization can be switched by the configuration of the enolate precursor. First examples of asymmetric oxidative radical cyclizations using N-(1-phenylethyl)-substituted beta-amino esters are reported. Only two of the four possible diastereomers are formed from the (E)-enolate with high cis-selectivity. From (Z)-enolates, an additional diastereomer is formed, which is likely to be formed only under chelation control.
Trvalý link: http://hdl.handle.net/11104/0178081