Ionic vs pericyclic transition states for the cyclization reactions of C alpha-N anions derived from amides and phosphinamides.
[structure: see text] Ab initio and DFT calculations indicate that the anionic cyclization of vinyl- and phenyl-carboxamides and phosphinamides metalated at the C(alpha)-N carbon fits better to a Michael-type ionic addition than to an electrocyclic ring closure. The lithium atom has no influence on the type of reaction mechanism.
Ramallal
Antonio Morán
AM
Departamento de Química Orgánica e Inorgánica, Universidad de Oviedo, c/Julián Clavería 8, 33006, Oviedo, Spain.
López-Ortiz
Fernando
F
González
Javier
J