title: Anisotropic and hydrogen bonding effects in phenylglyoxamides and mandelamides: theoretical and NMR conformational evaluation.
abstract: Interesting anisotropic effects were observed for phenylglyoxamides and their respective mandelamides. Such effects were observed in experimental (1)H and (13)C NMR (in CDCl(3), CD(3)OD, and DMSO-d(6) solvents) and in some cases with good correlation to theoretical (1)H and (13)C NMR DFT-GIAO (B3LYP/6-311++G**//B3LYP/6-31G*) calculations. A systematic conformational analysis of these compounds was performed in a two-step methodology, using PM3 and DFT (B3LYP/6-31G*) calculations; with good accomplishment and computational time economy. It was observed that intramolecular hydrogen bonding plays a significant role in the conformation of such compounds. Finally, a geminal nonequivalence of an N-CH(2) moiety, in one of the alkyl side chain (R1 = R2), was found for the tertiary mandelamides studied.
authors.affiliation: Departamento de Química Orgânica, Instituto de Química, Bloco A, 6 a Andar do CT, Universidade Federal do Rio de Janeiro, Cidade Universitária, Ilha do Fundão, RJ, Brazil, 21949900.
authors.forename: Biank T
authors.initials: BT
authors.lastname: Gonçalves
authors.forename: Pierre M
authors.initials: PM
authors.lastname: Esteves
authors.forename: Angelo C
authors.initials: AC
authors.lastname: Pinto
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Kaiser
authors.forename: Fernanda L
authors.initials: FL
authors.lastname: da Silva
authors.forename: Eduardo
authors.initials: E
authors.lastname: Miguez
authors.forename: Joaquim F M
authors.initials: JF
authors.lastname: da Silva
mesh_terms: D016880:Anisotropy; D003198:Computer Simulation; D006859:Hydrogen / Q000737:chemistry*; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008333:Mandelic Acids / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D013453:Sulfonylurea Compounds / Q000737:chemistry*
chemical_list: D008333:Mandelic Acids; D013453:Sulfonylurea Compounds; C032160:glyoxamide; C010413:mandelamide; D006859:Hydrogen