Selective construction of dispiro[indoline-3,2'-quinoline-3',3-indoline] and dispiro[indoline-3,2'-pyrrole-3',3-indoline] via three-component reaction

A convenient synthetic procedure for the construction of novel dispirooxindole motifs was successfully developed by base-promoted three-component reaction of ammonium acetate, isatins and in situ-generated 3-isatyl-1,4-dicarbonyl compounds. The pi-peridine-promoted three-component reaction of ammonium acetate, isatins and the in situ-generated dimedone adducts of 3-ethoxy-carbonylmethyleneoxindoles afforded mutlifunctionalized dispiro[indoline-3,2'-quinoline-3',3-indoline] derivatives in good yields and with high diastereoselectivity. On the other hand, a similar reaction of the dimedone adducts of 3-phenacylideneoxindoles afforded unique dispiro[indoline-3,2'-pyrrole-3',3-indoline] derivatives with a cyclohexanedione substituent. A plausible reaction mechanism is proposed to explain the formation of the different spirooxindoles.

Automated summary

A convenient method for constructing novel dispirooxindole motifs was developed through a base-promoted three-component reaction of ammonium acetate, isatins, and in situ-generated 3-isatyl-1,4-dicarbonyl compounds. The reaction of dimedone adducts of 3-ethoxy-carbonylmethyleneoxindoles with ammonium acetate and isatins, promoted by pi-peridine, produced multifunctionalized dispiro[indoline-3,2'-quinoline-3',3-indoline] derivatives with good yields and high diastereoselectivity. A similar reaction of dimedone adducts of 3-phenacylideneoxindoles yielded unique dispiro[indoline-3,2'-pyrrole-3',3-indoline] derivatives with a cyclohexanedione substituent. A plausible reaction mechanism is proposed to explain the formation of the different spirooxindoles.