TY - JOUR
T1 - Experimental and computational studies on interrupted Nazarov reactions
T2 - Exploration of umpolung reactivity at the α-carbon of cyclopentanones
AU - Wu, Yen Ku
AU - Dunbar, Christine R.
AU - McDonald, Robert
AU - Ferguson, Michael J.
AU - West, F. G.
N1 - Publisher Copyright:
© 2014 American Chemical Society.
PY - 2014/10/22
Y1 - 2014/10/22
N2 - A set of densely substituted, α-functionalized cyclopentanones can be generated by a two-component, domino reaction sequence entailing the Nazarov electrocyclization of divinyl ketones and nucleophilic addition of the resulting 2-oxidocyclopentenyl cations by selected trapping modalities. Bypassing the typical eliminative termination, Nazarov oxyallyl species can react with carbon π-nucleophiles through cycloadditions (or formal cycloadditions), in which bridged bicyclic systems are established, or nucleophilic trappings whereby one terminal carbon of the oxyallyl intermediate is subjected to carbon-carbon bond formation. A detailed investigation of reaction parameters to explicitly control the course of the "interrupted" Nazarov reactions is described. This methodology allows for facile installation of α-quaternary centers bearing allyl, alkynyl, and heteroaryl groups in an umpolung fashion. In addition, the trapping event of a Nazarov intermediate with furan was studied by DFT computations, in conjunction with experimental data, offering a rationale for the observed reaction pattern and diastereoselectivity.
AB - A set of densely substituted, α-functionalized cyclopentanones can be generated by a two-component, domino reaction sequence entailing the Nazarov electrocyclization of divinyl ketones and nucleophilic addition of the resulting 2-oxidocyclopentenyl cations by selected trapping modalities. Bypassing the typical eliminative termination, Nazarov oxyallyl species can react with carbon π-nucleophiles through cycloadditions (or formal cycloadditions), in which bridged bicyclic systems are established, or nucleophilic trappings whereby one terminal carbon of the oxyallyl intermediate is subjected to carbon-carbon bond formation. A detailed investigation of reaction parameters to explicitly control the course of the "interrupted" Nazarov reactions is described. This methodology allows for facile installation of α-quaternary centers bearing allyl, alkynyl, and heteroaryl groups in an umpolung fashion. In addition, the trapping event of a Nazarov intermediate with furan was studied by DFT computations, in conjunction with experimental data, offering a rationale for the observed reaction pattern and diastereoselectivity.
UR - http://www.scopus.com/inward/record.url?scp=84908397753&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84908397753&partnerID=8YFLogxK
U2 - 10.1021/ja507638r
DO - 10.1021/ja507638r
M3 - Article
C2 - 25310874
AN - SCOPUS:84908397753
SN - 0002-7863
VL - 136
SP - 14903
EP - 14911
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 42
ER -