Umpolung of donor-acceptor cyclopropanes via N-heterocyclic carbene organic catalysis was written by Nie, Guihua;Huang, Xuan;Wang, Zhongyao;Pan, Dingwu;Zhang, Junmin;Chi, Yonggui Robin. And the article was included in Organic Chemistry Frontiers in 2021.SDS of cas: 774-47-0 This article mentions the following:
A N-heterocyclic carbene-catalyzed (NHC) formal umpolung of donor-acceptor (D-A) cyclopropanes was disclosed. The cyclopropane moiety was connected to an acetyl aldehyde that could be activated by a carbene catalyst. The initially electrophilic carbon attached to the donor group of the D-A cyclopropane aldehyde was inverted to form a nucleophilic reaction center. A subsequent reaction with isatins via a formal [3 + 2] process formed lactones I [R = H, 4-Br, 5-Me, etc.; R1 = Bn, trityl; R2 = OMe, OEt, O(i-Pr), OBn] bearing multiple functional groups with excellent enantio- and diastereoselectivities. In the experiment, the researchers used many compounds, for example, 5,6-Difluoroindoline-2,3-dione (cas: 774-47-0SDS of cas: 774-47-0).
5,6-Difluoroindoline-2,3-dione (cas: 774-47-0) belongs to indole derivatives. Indole, first isolated in 1866, and it is commonly synthesized from phenylhydrazine and pyruvic acid, although several other procedures have been discovered.Indole was synthesized in moderate yield via an o-naphthoquinone catalyzed tandem cross-coupling of substituted aniline and benzylamine under aerobic oxidation conditions.SDS of cas: 774-47-0
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Indole alkaloid derivatives as building blocks of natural products from Bacillus thuringiensis and Bacillus velezensis and their antibacterial and antifungal activity study,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles