Efficient Synthesis of 2,3′-Spirobi (Indolin)-2′-Ones and Preliminary Evaluation of Their Damage to Mitochondria in HeLa Cells

A novel formal (4 + 1) annulation between N-(o-chloromethyl)aryl amides and 3-chlorooxindoles through in situ generated aza-ortho-QMs with 3-chlorooxindoles is reported for the synthesis of a series of 2,3′-spirobi (indolin)-2′-ones in high yields. Under structured illumination microscopy, compound 3a is found to change the mitochondrial morphology and induce mitophagy pathway, which might then trigger mitophagy in cancer cells.