Regio- and Stereoselective 1,3-dipolar Cycloaddition of Azomethine Ylides Based on Isatins and (thia)proline to 3-nitro-2-(trifluoro(trichloro)methyl)-2H-chromenes: Synthesis and Cytotoxic Activity of 6-(trihalomethyl)-spiro[chromeno(thia)pyrrolizidine-11,3'-indolin]-2'-ones

A regio- and stereoselective method for the synthesis of (trifluoro(trichloro)methyl)-substituted spiro[chromeno(thia)pyrrolizidineoxindoles] in 53–97% yields was developed on the basis of the three-component reaction of 3-nitro-2-(trifluoro(trichloro)methyl)-2Hchromenes with azomethine ylides generated in situ from isatins and L-(thia)proline in EtOH at 30°C. The obtained compounds demonstrated high cytotoxic activity against HeLa human cervical cancer and RD human embryonic rhabdomyosarcoma cells.