830-93-3Relevant articles and documents
Rhodium-Catalyzed Stereoselective Cyclization of 3-Allenylindoles and N-Allenyltryptamines to Functionalized Vinylic Spiroindolenines
Becker, Antonia,Breit, Bernhard,Grugel, Christian P.
supporting information, p. 3788 - 3792 (2021/05/29)
Herein, we report a highly enantio- and diastereoselective rhodium-catalyzed cyclization of N-allenyltryptamines and 3-allenylindoles to 6-membered spirocyclic indolenines. This allylic addition methodology offers the advantage of using a comparably cheap commercially available ligand with low loadings of an affordable rhodium precursor. The products can be converted into functionalized spirooxindoles and spiroindolines, which are regarded as important building blocks for the synthesis of a lot of natural products with biological activities.
Natural Products for Drug Discovery: Discovery of Gramines as Novel Agents against a Plant Virus
Lu, Aidang,Wang, Tienan,Hui, Hao,Wei, Xiaoye,Cui, Weihao,Zhou, Chunlv,Li, Hongyan,Wang, Ziwen,Guo, Jincheng,Ma, Dejun,Wang, Qingmin
, p. 2148 - 2156 (2019/03/08)
Plant viral diseases seriously affect crop yield and quality. The natural product gramine (1) and its simple structural analogues 2-35 were synthesized from indoles, amines, and aldehydes in one step. The antiviral effects of these alkaloids were evaluated systematically. Most of these compounds were found to have higher antiviral effects than commercial ribavirin for the first time. Especially compounds 22, 30, and 31 exhibited significantly higher effects than ningnanmycin, thereby emerging as novel antiviral leads for further optimization. The preliminary implementation indicated that these compounds likely inhibit the assembly of tobacco mosaic virus (TMV) by cross-linking TMV capsid protein. Gramine analogues were also found to have broad-spectrum fungicidal effects. Although gramine has been reported to have influence on germination and development of Erysiphe graminis, these compounds displayed no fungicidal effects against Blumeria graminis f. sp. tritici on wheat in our test. Some of these compounds also exhibited certain insecticidal activities.
Rhodium-Catalyzed Diastereo- And Enantioselective Tandem Spirocyclization/Reduction of 3-Allenylindoles: Access to Functionalized Vinylic Spiroindolines
Grugel, Christian P.,Breit, Bernhard
supporting information, p. 9672 - 9676 (2019/12/24)
A highly selective rhodium-catalyzed tandem spirocyclization/reduction of 3-allenylindoles is reported. By employing a Hantzsch ester as reductant, vinylic spiroindolines are obtained in excellent yields as well as diastereo- and enantioselectivity. In addition, the reaction's synthetic utility is highlighted by broad functional group compatibility and exemplified by a gram scale reaction with subsequent assorted transformations.