Dynamic Covalent Metathesis in the CâC/CâN Exchange between Knoevenagel Compounds and Imines.
J Am Chem Soc
; 140(16): 5560-5568, 2018 04 25.
Article
en En
| MEDLINE
| ID: mdl-29616806
ABSTRACT
Fast and reversible dynamic covalent CâC/CâN exchange takes place without catalyst in nonpolar solvents between barbiturate-derived Knoevenagel (Kn) compounds and imines. A detailed study of the reaction indicates that it proceeds by an associative organo-metathesis mechanism involving the formation of a four-membered ring azetidine intermediate by addition of the imine CâN group to the CâC bond of the Kn compound. This intermediate could be generated cleanly and stabilized at low temperature by condensation of the o,p-dinitrophenyl Kn derivative with the cyclic imine 1-azacyclohexene. It was characterized by extensive NMR and mass spectrometric studies. The process described represents a genuine dynamic covalent organo-metathesis through a four-membered ring adduct as intermediate. It paves the way for the exploration of a wide set of dynamic systems involving (strongly) polarized CâC bonds and various imines, extending also into covalent dynamic polymers and polymolecular assemblies.
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Bases de datos:
MEDLINE
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En
Revista:
J Am Chem Soc
Año:
2018
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Article
País de afiliación:
Francia