title: Theoretical study of the regioselective cyclization of enaminones in the construction of benzofurans and indoles.
abstract: A theoretical study was undertaken regarding the regioselective Lewis acid-promoted intramolecular cyclization of novel enaminones 1-3 leading to the corresponding benzofurans 4-5 and indoles 6. The density functional theory (DFT) and hard and soft acids and bases (HSAB) principle provided data to describe the electronic effects of the substituents in the reactivity of the benzene ring and the enaminone moiety. The condensed and local Fukui functions for nucleophilic and electrophilic attacks of the reactants accounted for the experimentally observed preference, in regard to precursors 1-3, of the cyclization between the C6' carbon (rather than the C2' carbon) of the benzene ring and the C3 center of the enaminone moiety.
authors.affiliation: Instituto de Investigaciones Quimicobiológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edif. B-1, Ciudad Universitaria, Francisco J. Mujica s/n, 58066, Morelia, MI, Mexico. rhbucio@umich.mx.
authors.forename: Rafael
authors.initials: R
authors.lastname: Herrera
authors.affiliation: Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, A.P. 55-534, 09340, Mexico, D.F., Mexico. fm@xanum.uam.mx.
authors.forename: Francisco
authors.initials: F
authors.lastname: Méndez
authors.affiliation: Centro de Investigación en Biotecnología Aplicada, Instituto Politécnico Nacional, Km 15 Carretera Sta. Inés Tecuexcomac, Tepetitla, 90700, Tlaxcala, Mexico.
authors.forename: Fabiola
authors.initials: F
authors.lastname: Jiménez
authors.affiliation: Centro de Investigación en Biotecnología Aplicada, Instituto Politécnico Nacional, Km 15 Carretera Sta. Inés Tecuexcomac, Tepetitla, 90700, Tlaxcala, Mexico.
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Cruz
authors.affiliation: Departamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prol. Carpio y Plan de Ayala S/N, 11340, Mexico, D.F., Mexico. jtamarizm@gmail.com.
authors.forename: Joaquín
authors.initials: J
authors.lastname: Tamariz
mesh_terms: D001572:Benzofurans / Q000737:chemistry*; D003500:Cyclization; D007211:Indoles / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D009285:Naphthoquinones / Q000737:chemistry*; D011789:Quantum Theory; D012044:Regression Analysis; D013237:Stereoisomerism; D013816:Thermodynamics
chemical_list: D001572:Benzofurans; D007211:Indoles; D009285:Naphthoquinones
keywords: Cyclization; DFT/HSAB theory; Enaminones; Fukui function; Lewis acid catalysis