Blue LED Irradiation of Iodonium Ylides Gives Diradical Intermediates for Efficient Metal‐free Cyclopropanation with Alkenes
作者:Tristan Chidley、Islam Jameel、Shafa Rizwan、Philippe A. Peixoto、Laurent Pouységu、Stéphane Quideau、W. Scott Hopkins、Graham K. Murphy
DOI:10.1002/anie.201908994
日期:2019.11.18
A facile and highly chemoselective synthesis of doubly activated cyclopropanes is reported where mixtures of alkenes and β-dicarbonyl-derived iodoniumylides are irradiated with light from blue LEDs. This metal-free synthesis gives cyclopropanes in yields up to 96 %, is operative with cyclic and acyclic ylides, and proceeds with a variety of electronically-diverse alkenes. Computational analysis explains
(diacetoxyiodo)-arenes, ArI(OAc)2, or iodylarenes, ArIO2, from the corresponding iodoarenes, ArI, using sodium periodate as the oxidant are presented in this paper. In order to obtain 2- and 4-iodylbenzoic acids, the respective sodium salts of 2- and 4-iodobenzoic acids should be used as the starting substrates, because mixtures containing the corresponding iodosyl derivatives as the main products
Further functional group oxidations using sodium perborate
作者:Alexander McKillop、Duncan Kemp
DOI:10.1016/s0040-4020(01)81008-5
日期:1989.1
Sodiumperborate in acetic acid is an effective reagent for the oxidation of aromatic aldehydes to carboxylic acids, iodoarenes to (diacetoxyiodo)arenes, azines to -oxides, and various types of sulphur heterocycles to ,-dioxides. Nitriles are unaffected by the reagent in acetic acid, but undergo smooth hydration to amides when aqueous methanol is employed as solvent.
Transition-Metal-Free<i>N</i>-Arylation of Pyrazoles with Diaryliodonium Salts
作者:Zsombor Gonda、Zoltán Novák
DOI:10.1002/chem.201502995
日期:2015.11.16
developed for the N‐arylation of pyrazoles using diaryliodoniumsalts. The transformation does not require any transition‐metal catalyst and provides the desired N‐arylpyrazoles rapidly under mild reaction condition in the presence of aqueous ammonia solution as a mild base without the use of inert atmosphere. The chemoselectivity of unsymmetric diaryliodoniumsalts was also explored with large number
compatibility and air and moisture tolerance. An efficientprotocol for the synthesis of O-aroyl-N,N-dimethylhydroxylamines, which are important electrophilic amination reagents, is described. The reaction between carboxylicacids and N,N-dimethylformamide is mediated by hypervalent iodine and occurs under mild conditions at room temperature to give the desired products in good yields. The process shows good