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

Abstract
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 piperidine-promoted three-component reaction of ammonium acetate, isatins and the in situ-generated dimedone adducts of 3-ethoxycarbonylmethyleneoxindoles 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.

Beilstein J. Org. Chem. 2023, 19, 1234–1242. doi:10.3762/bjoc.19.91

Source: Beilstein Journal of Organic Chemistry - August 22, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: cascade reaction dimedone isatin 3-methyleneoxindole multicomponent reaction spirooxindole Full Research Paper Source Type: research