One‐Pot Synthesis of Dispiro[oxindole‐3,3′‐pyrrolidines] by Three‐Component [3+2] Cycloadditions of in situ‐Generated Azomethine Ylides with 3‐Benzylidene‐2,3‐dihydro‐1H‐indol‐2‐ones

TLDR: An efficient one-pot, three-component synthesis of novel dispiro[oxindole-3,3′-pyrrolidines] by 1,3-dipolar cycloaddition of azomethine ylides, in situ generated by reaction of 1,2-diones with sarcosine and subsequent decarboxylation, with a series of (E)-3-benzylidene-2, 3-dihydro-1H-indol-2-ones is reported as discussed by the authors.

Abstract: An efficient one-pot, three-component synthesis of novel dispiro[oxindole-3,3′-pyrrolidines] by 1,3-dipolar cycloaddition of azomethine ylides, in situ generated by reaction of 1,2-diones with sarcosine and subsequent decarboxylation, with a series of (E)-3-benzylidene-2,3-dihydro-1H-indol-2-ones is reported. Molecular complexity is generated in only one synthetic step. All reactions proceed with excellent regioselectivity and in good-to-excellent yields. The workup is easy, the reaction times are short, and no catalyst is required.