A high temperature investigation using microwave synthesis for electronically and sterically disfavoured substrates of the Newman–Kwart rearrangement
作者:Jonathan D. Moseley、Philip Lenden
DOI:10.1016/j.tet.2007.02.101
日期:2007.5
Electronically deactivated and/or sterically hindered substrates undergo the Newman–Kwartrearrangement (NKR) at around 300 °C, beyond the range of most convenient and safe, small-scale laboratory equipment. We report here the convenient conversions of several difficult substrates using modern microwave technology, which has proven ideal for investigating this high temperature reaction in all but the most
The insertion reaction of isocyanides with thiocarbamates and selenocarbamates in the presence of a Pd(0) catalyst to selectively give 2-oxoethanimidothioates and -selenoates is reported. This is the first example of the insertion of an isocyanide into a carbon–heteroatom bond using a transition-metal catalyst. DFT calculations suggest that the reaction proceeds through a thiopalladation pathway at the migratory insertion process.
作者:Thibault Gendron、Raul Pereira、Hafsa Y. Abdi、Timothy H. Witney、Erik Årstad
DOI:10.1021/acs.orglett.9b04280
日期:2020.1.3
Herein, we report that iron(II)/ammonium persulfate in aqueous acetonitrile mediates the Newman-Kwart rearrangement of O-aryl carbamothioates. Electron-rich substrates react rapidly under moderate heating to afford the rearranged products in excellent yields. The mild conditions, rapid reaction rates, and suitability for scale up offers immediate practical benefits to access functionalized thiophenols
An Electrocatalytic Newman–Kwart-type Rearrangement
作者:Timo Broese、Arend F. Roesel、Adrian Prudlik、Robert Francke
DOI:10.1021/acs.orglett.8b03257
日期:2018.12.7
An electrochemical approach toward rearrangement of O-aryl thiocarbamates to the corresponding S-aryl thiocarbamates is presented. The protocol requires only catalytic amounts of electric charge and allows for operation at room temperature. The electrolysis can be carried out with the simplest equipment, i.e., under galvanostatic conditions in an undivided cell. Furthermore, it is demonstrated that
Inverting the Selectivity of the Newman–Kwart Rearrangement via One Electron Oxidation at Room Temperature
作者:Stephan K. Pedersen、Anne Ulfkjær、Madeleine N. Newman、Sarangki Yogarasa、Anne U. Petersen、Theis I. Sølling、Michael Pittelkow
DOI:10.1021/acs.joc.8b01800
日期:2018.10.5
The discovery that the Newman–Kwartrearrangement can be performed at room temperature by action of a simple and readily available oxidant, cerium ammonium nitrate, is described. The conditions give clean conversion when using electron-rich aromatic substrates, and the reactions are often quantitative. Computational studies support a reaction mechanism where the O-thiocarbamate is first oxidized to