Publication Date:
2011-03-10
Description:
Dienes embedded in quinolizidine and indolizidine structures can be prepared in four steps from cyclic nitrones and bicyclopropylidene. The key intermediates α-spirocyclopropanated N -heterocyclic ketones, generated via a domino 1,3-dipolar cycloaddition/thermal rearrangement sequence, were converted by Wittig methylenation to the corresponding vinylcyclopropanes (VCPs), which underwent rearrangement to 1,3-dienes in the presence of the Wilkinson Rh(I) complex under microwave heating. The previously unexplored Rh(I)-catalyzed opening of the VCP moiety embedded in an azapolycyclic system occurs at high temperature (110–130 °C) to afford the corresponding 1,3-dienes in moderate yield (34–53%). Beilstein J. Org. Chem. 2011, 7, 298–303. doi:10.3762/bjoc.7.39
Keywords:
nitrogen heterocyclesrearrangementrhodiumsmall ring systemsspiro compounds
Electronic ISSN:
1860-5397
Topics:
Chemistry and Pharmacology
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