Regio- and diastereoselective synthesis of anticancer spirooxindoles derived from tryptophan and histidine via three-component 1,3-dipolar cycloadditions in an ionic liquid.

Abstract A small library of novel hybrid spiroheterocycles containing spirooxindole, pyrrolidine and indole/imidazole moieties were synthesized with complete regio- and diastereoselectively in good to excellent yields from a three-component process starting from a series of variously substituted ( E )-(2-nitrovinyl)benzenes, indoline-2,3-dione derivatives and l -tryptophan or l -histidine in an ionic liquid. The key step of this transformation is a 1,3-dipolar cycloaddition reaction involving a rare class of in situ -generated azomethine ylides derived from aromatic amino acids. The compounds thus synthesized were evaluated for their anticancer activity and were shown to inhibit the proliferation of FaDu cells, a human epithelial cell line isolated from a squamous cell carcinoma of the hypopharynx, via apoptotic cell death. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]