Formation of spirocyclic compounds from Heck cyclizations invoking cyclic enamides
Gedu Satyanarayana1, Martin E Maier
1Institut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.
Abstract:
The palladium-mediated transformation of 3,4-dihydro-2(1H)-pyridinones 12 featuring a (2-bromophenyl)ethyl substituent in the 5-position produces spirocyclic products, imides 14 and amides 15. The formation of these products can be explained by insertion of the enamide double bond into the initial aryl-Pd bond followed by oxidation or reduction of the organopalladium intermediate. Alternatively, formation of these spiro compounds might proceed via acyliminium ion intermediates.
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