Stereoselective synthesis, structural determination, computational studies and antimicrobial activity of novel class of spiropyrroloquinoxaline engrafted ferrocenoindole hybrid heterocycle

Abstract

Our synthetic approach for the assembly of highly diversified spiropyrrolidine grafted ferrocene was based on a one-pot four component cascade reaction protocol involving 1,3-dipolar cycloaddition reaction of (E)-3-ferrocene-1-(4-bromophenyl)prop‑2-en-1-one and azomethine ylide generated in situ from quinoxalinone and l-tryptophan. The structure of the compound was assigned by one- and two-dimensional NMR spectroscopic studies. The regio- and stereochemistry of the spirocompound was confirmed by single crystal X-ray diffraction analysis. The nature of three-dimensional orientation of the synthesized compound has been investigated through single crystal X-ray diffraction study. Crystal structure of the synthesized compound was analyzed using Hirshfeld calculations. In spirocompound, the packing of molecules is controlled by significant O…H (3.3%), N…H (4.1%) and CH…π (24.8%) interactions. The different π-donation and π-back donation interactions was analysed using NBO calculations. The compound 6 exhibited potent inhibitory activity against tested MDR S. aureus strains ranging from 8.00 to 256.00 µg/mL with respect to MIC and MBC determination.