IQUIBA-NEA   25617
INSTITUTO DE QUIMICA BASICA Y APLICADA DEL NORDESTE ARGENTINO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Theoretical DFT study of the NMR parameters, shielding and spin-spin coupling constant, of the products of a pinacol alkenylboronates? Diels- Alder reaction
Autor/es:
VALLEJOS, MARGARITA M.; ZARYCZ, M. NATALIA C.; PROVASI, PATRICIO F.; PELLEGRINET, SILVINA C.
Lugar:
Montevideo
Reunión:
Congreso; 42nd International Congress of Theoretical Chemists of Latin Expression; 2016
Resumen:
We havestudied theoretically some magnetic properties for selected products of theDiels-Alder reactions for pinacol alkenylboronates with cyclopentadiene, whichrecently were synthesized and their structures were determined by acombination of spectroscopic methods such as Infrared (IR), 1D and 2D Nuclear MagneticResonance (NMR) and High Resolution Mass Spectrometry (HRMS). We calculated theNMR parameters, shielding (σ) andspin-spin coupling constant (J), for five reported boronate cycloadducts at B3LYP/cc-pVTZ-Jlevel of theory, in order to help the elucidation of the NMR experimentalspectra, i. e., to verify the assigned signals and to clarify the origin ofambiguous ones. We also seek to predict some signals that could not beexperimentally determined and therefore gives further support to the NMRstructure characterization of this kind of compound.We found thatmost of the experimental assignations are in good agreement with thecalculations in this work. The computational data exhibit to be a good tool toclarify the nuclei which gives the signals that could not be preciselyassigned. We also propose some possible σ?s and J?svalues which could not be measured experimentally. Moreover we analyzecarefully the shieldings and coupling constants within the bicycle [2.2.1]heptanebackbone and separately in the boron-substituent.