Synthesis of Spiro[pyrazolin-3,3'-oxindoles] and 3-Arylcarbonylmethyl Substituted Ylideneoxindoles by 1,3-Dipolar Cycloadditions of 3-Ylideneoxindoles and In-Situ-Generated α-Diazoketones.

An efficient 1,3-dipolar cycloaddition of 3-ylideneoxindoles with in-situ-generated α-diazoketones to potentially biological active spiro[pyrazolin-3,3'-oxindoles] 4 with excellent regioselectivity and diastereoselectivity and synthetically useful building block 3-arylcarbonylmethyl substituted ylideneoxindoles 5 in different conditions has been developed. This method has advantages of mild conditions, simple workup, and wide substrate scopes as well as without using any transition metal catalyst.