Intramolecular azide trapping of the Nazarov intermediate: formation of peroxy-bridged indolizidinones via a deep-seated rearrangement and aerobic oxidation.
Cross-conjugated dienones with pendent azide side chains undergo interrupted Nazarov trapping, leading to peroxy-bridged indolizidinones in good yields. This process is proposed to involve skeletal rearrangement of the initial trapping product, with loss of dinitrogen, to give an intermediate 1,4-betaine, which then undergoes reaction with atmospheric oxygen. The endoperoxide products can be reduced under catalytic hydrogenation conditions to furnish alpha-hydroxylactams. [reaction: see text].
Rostami
Ali
A
Department of Chemistry, University of Alberta, Edmonton, AB, Canada T6G 2G2.
Wang
Yong
Y
Arif
Atta M
AM
McDonald
Robert
R
West
F G
FG
D000332:Aerobiosis; D001386:Azides / Q000737:chemistry*; D001622:Betaine / Q000737:chemistry; D001952:Bridged-Ring Compounds / Q000138:chemical synthesis*; D002384:Catalysis; D006865:Hydrogenation; D007212:Indolizines / Q000138:chemical synthesis*; D013058:Mass Spectrometry; D010084:Oxidation-Reduction
D001386:Azides; D001952:Bridged-Ring Compounds; D007212:Indolizines; D001622:Betaine