Stereoselective green synthesis and molecular structures of highly functionalized spirooxindole-pyrrolidine hybrids – A combined experimental and theoretical investigation

摘要

AbstractHighly functionalized spirooxindole-pyrrolidine hybrids have been synthesized stereoselectively through a [3?+?2] cycloaddition strategy in an ionic liquid, 1-butyl-3-methylimidazolium bromide ([bmim]Br). The structure of these spiro heterocyclic hybrids was elucidated using one and two dimensional NMR spectroscopy, single crystal X-ray crystallographic studies and Density Functional Theory (DFT) calculations. The calculated geometric parameters are in good agreement with the experimental data obtained from the X-ray structures. The Natural Bond Orbital (NBO) calculations on these molecules confirm the electron rich carbonyl oxygen and electron deficient NH groups. The1H and13C NMR chemical shifts calculated using GIAO method are in good agreement with the experimental data. The DFT computed polarizability values also suggest the possible NLO activity of these molecules.Graphical abstractStereoselective green synthesis of new spirooxindole-pyrrolidine hybrids4and6were synthesized and their structures were confirmed by NMR spectra, X-ray crystallography and DFT studies. The DFT computed polarizability values suggest the possible NLO property of the synthesized compounds.Display Omitted