We report the diastereoselective cyclization of anilines with cyclobutanones and congeners by chromium catalysis. This reaction can link two strained four-membered rings with tetrahydroquinolines by forming four bonds in a diastereocontrolled manner, forming medicinally interesting cyclobutane-fused and constrained spirotetrahydroquinolines (STHQs) and complex multiple spiro carbon-containing polyazacycles
A12, and A4, respectively. Further flow cytometric testing revealed compound A9 (R1) to be highly cytotoxic, with an IC50 value of 20.77 M. The anticancer activity of A9 (R1) against HT-29 colon cancer cell lines was also confirmed by in vitro results. Conclusion: These findings suggested that 2-pyridone compounds have promising therapeutic potential for cancer treatment, and more research on these