61675-19-2Relevant articles and documents
Recyclable and reusablen-Bu4NBF4/PEG-400/H2O system for electrochemical C-3 formylation of indoles with Me3N as a carbonyl source
Cheng, Didi,Li, Jingyi,Li, Yujin,Ling, Fei,Liu, Lei,Liu, Tao,Zhong, Weihui
supporting information, p. 4107 - 4113 (2021/06/17)
A safe, practical and eco-friendly electrochemical methodology for the synthesis of 3-formylated indoles has been developed by the utilization of Me3N as a novel formylating reagent. Stoichiometric oxidants, metal catalysts, and activating agents were avoided in this method, and an aqueous biphasic system ofn-Bu4NBF4/PEG-400/H2O was used as a recyclable and reusable reaction medium, which made this electrosynthesis approach more sustainable and environmentally friendly. This process expanded the substrate scope and functional group tolerance for bothN-EDG andN-EWG indoles. Furthermore, late-stage functionalization and total/formal synthesis of drugs and natural products were realized by means of this route.
Metal-Free Dearomatization: Direct Access to Spiroindol(en)ines in Batch and Continuous-Flow
Ranjan, Prabhat,Ojeda, Gerardo M.,Sharma, Upendra K.,Van der Eycken, Erik V.
supporting information, p. 2442 - 2446 (2019/01/29)
A metal-free, phosphine-catalyzed intramolecular “umpolung Michael addition” on alkynes to form spiroindol(en)ines is reported. This nucleophilic catalysis enables the formation of a wide scope of five- and six-membered spiroindol(en)ines in moderate to excellent yields in batch as well as under continuous-flow conditions. Triphenylphosphine-catalyzed nucleophilic activation of alkynes allows the exclusive formation of exo-product under mild reaction conditions.
An environmentally friendly protocol for oxidative halocyclization of tryptamine and tryptophol derivatives
Xu, Jun,Tong, Rongbiao
supporting information, p. 2952 - 2956 (2017/07/24)
An environmentally friendly and efficient protocol (KX/oxone) for oxidative halocyclization of tryptamine/tryptophol derivatives was developed and demonstrated with 28 examples and concise total synthesis of cyclotryptamine alkaloid protubonines A and B. The distinct advantage of this protocol over all previous methods is that no organic byproduct is generated from a halogenating agent or oxidant, thus greatly reducing the environmental impact of halocyclization and facilitating the post-reaction purification.