Copper mediated cyclization of activated 1-substituted enamides occurs via a 5-endo radical-polar cross-over process. Trichloroacetyl derivatives can undergo further reactions post cyclization (elimination of HCl or dimerization potentially via copper carbenoid intermediates). Reaction of alpha-halo trienamides derived from beta-ionone furnish either beta- or gamma-lactams via 4-exo or 5-exo cyclizations respectively depend- ing upon the enamide tautomer undergoing reaction. For the less reactive dichloroacetamide derivative a competing regioselective methyl migration-aromatization prior to cyclization is observed.
Copper mediated cyclization of 1-substituted enamides, dienamides and trienamides: regiochemistry, indigoid formation and methyl migration-aromatization / Geden, Joanna V.; Clark, Andrew J.; Coles, Stuart R.; Guy, Collette S.; Ghelfi, Franco; Thom, Stephen. - In: TETRAHEDRON LETTERS. - ISSN 0040-4039. - 57:29(2016), pp. 3109-3112. [10.1016/j.tetlet.2016.06.009]
Copper mediated cyclization of 1-substituted enamides, dienamides and trienamides: regiochemistry, indigoid formation and methyl migration-aromatization
GHELFI, Franco;
2016
Abstract
Copper mediated cyclization of activated 1-substituted enamides occurs via a 5-endo radical-polar cross-over process. Trichloroacetyl derivatives can undergo further reactions post cyclization (elimination of HCl or dimerization potentially via copper carbenoid intermediates). Reaction of alpha-halo trienamides derived from beta-ionone furnish either beta- or gamma-lactams via 4-exo or 5-exo cyclizations respectively depend- ing upon the enamide tautomer undergoing reaction. For the less reactive dichloroacetamide derivative a competing regioselective methyl migration-aromatization prior to cyclization is observed.
Pubblicazioni consigliate
I metadati presenti in IRIS UNIMORE sono rilasciati con licenza Creative Commons CC0 1.0 Universal, mentre i file delle pubblicazioni sono rilasciati con licenza Attribuzione 4.0 Internazionale (CC BY 4.0), salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris
