机译: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)-spirochromeno(thia)pyrrolizidine-11,3 '-indolin-2 '-ones