A novel and efficient two-step synthetic sequence for the preparation of 3,3-disubstituted oxindoles was developed starting from arylhydrazines and α-branched aldehydes via Fischer indole type synthesis followed by imine oxidation.
A series of 15 benzene-fused hexahydropyrrolo[1,2-b]isoquinolonic acids with substantial degree of steric encumbrance has been prepared via a novel variant of the Castagnoli-Cushman reaction of homophthalic anhydride (HPA) and various indolenines. The employment of a special kind of a cyclic imine component reaction allowed, for the first time, isolating a Mannich-type adduct between HPA and an imine
Sterically Constrained and Encumbered: An Approach to the Naturally Occurring Peptidomimetic Tetrahydropyrazino[1,2-<i>a</i>]indole-1,4-dione Core
作者:Pavel Golubev、Mikhail Krasavin
DOI:10.1002/ejoc.201700152
日期:2017.4.3
The combination of two privileged motifs, that is, indoline and the constrainedpeptidomimetic piperazine-2,5-dione, within one tricyclic structure resulted in a scaffold that is abundant in nature but surprisingly scarce in the domain of synthetic bioactive molecules. Utilizing the power of the isocyanide-based Joullie–Ugi reaction followed by postcondensation cyclization, we synthesized such compounds
We developed an environmentally friendly mechanochemical protocol to induce an effective Fischer indolisation to synthesize indoles and indolines taking advantage of oxalic acid and dimethylurea.