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
Ambient-Temperature Newman–Kwart Rearrangement Mediated by Organic Photoredox Catalysis
作者:Andrew J. Perkowski、Cole L. Cruz、David A. Nicewicz
DOI:10.1021/jacs.5b11800
日期:2015.12.23
The Newman-Kwartrearrangement is perhaps the quintessential method for the synthesis of thiophenols from the corresponding phenol. However, the high thermal conditions required for the rearrangement of the requisite O-aryl carbamothioates often leads to decomposition. Herein, we present a general strategy for catalysis of O-aryl carbamothioates to S-aryl carbamothioates using catalytic quantities
new developments, a better understanding of the underlying principles is crucial. In this context, we have studied the Newman–Kwartrearrangement of O-arylthiocarbamates to the corresponding S-aryl derivatives, the key step in the synthesis of thiophenols from the corresponding phenols. This transformation is a particularly useful example because the conventional method requires temperatures up to 300 °C