84695-11-4Relevant academic research and scientific papers
Electrochemically Catalyzed Newman-Kwart Rearrangement: Mechanism, Structure-Reactivity Relationship, and Parallels to Photoredox Catalysis
Roesel, Arend F.,Ugandi, Mihkel,Huyen, Nguyen Thi Thu,Májek, Michal,Broese, Timo,Roemelt, Michael,Francke, Robert
, p. 8029 - 8044 (2020/07/25)
The facilitation of redox-neutral reactions by electrochemical injection of holes and electrons, also known as "electrochemical catalysis", is a little explored approach that has the potential to expand the scope of electrosynthesis immensely. To systematically improve existing protocols and to pave the way toward new developments, a better understanding of the underlying principles is crucial. In this context, we have studied the Newman-Kwart rearrangement 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, whereas electrochemical catalysis facilitates the reaction at room temperature. A combined experimental-quantum chemical approach revealed several reaction channels and rendered an explanation for the relationship between the structure and reactivity. Furthermore, it is shown how rapid cyclic voltammetry measurements can serve as a tool to predict the feasibility for specific substrates. The study also revealed distinct parallels to photoredox-catalyzed reactions, in which back-electron transfer and chain propagation are competing pathways.
Microwave-mediated Newman-Kwart rearrangement in water
Hoffmann, Ina,Schatz, Jürgen
, p. 80692 - 80699 (2016/09/09)
For the first time the unimolecular Newman-Kwart rearrangement is performed in pure water. The elevated temperatures required for the 1,3-aryl shift are easily accomplished by microwave irradiation. Differently functionalized substrates underline the expe
Ago-allosteric modulators of human glucagon-like peptide 2 receptor
Yamazaki, Kazuto,Terauchi, Hiroki,Iida, Daisuke,Fukumoto, Hironori,Suzuki, Shuichi,Kagaya, Takaki,Aoki, Mika,Koyama, Koichiro,Seiki, Takashi,Takase, Kazuma,Watanabe, Misako,Arai, Tohru,Tsukahara, Kappei,Nagakawa, Junichi
, p. 6126 - 6135 (2012/10/30)
Glucagon-like peptide 2 (GLP-2) is an intestinotropic peptide that binds to GLP-2 receptor (GLP-2R), a class-B G protein-coupled receptor (GPCR). Few synthetic agonists have been reported so far for class-B GPCRs. Here, we report the first scaffold compounds of ago-allosteric modulators for human GLP-2R, derived from methyl 2-{[(2Z)-2-(2,5-dichlorothiophen-3-yl)-2-(hydroxyimino) ethyl]sulfanyl}benzoate (compound 1).
A high temperature investigation using microwave synthesis for electronically and sterically disfavoured substrates of the Newman-Kwart rearrangement
Moseley, Jonathan D.,Lenden, Philip
, p. 4120 - 4125 (2008/01/03)
Electronically deactivated and/or sterically hindered substrates undergo the Newman-Kwart rearrangement (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 refractory of cases. In addition, several previously reported difficult examples were re-investigated, and found not to require high temperatures under these conditions, for various reasons which are elaborated upon.
The Newman-Kwart rearrangement re-evaluated by microwave synthesis
Moseley, Jonathan D.,Sankey, Rosalind F.,Tang, Olivier N.,Gilday, John P.
, p. 4685 - 4689 (2007/10/03)
The Newman-Kwart rearrangement (NKR) has been re-evaluated by microwave heating. Microwave technology has proven to be ideal for investigating this high temperature rearrangement and facilitated the confirmation of many aspects of this valuable reaction.
Infrared Spectra and Transmission of Electronic Effects in Substituted Phenyl N,N-Dimethylcarbamates and S-Phenyl N,N-Dimethylthiocarbamates
Perjessy, Alexander,Jones, Ronald G.,McClair, Susan L.,Wilkins, Joyce M.
, p. 1266 - 1271 (2007/10/02)
Carbonyl stretching frequencies in CCl4 and CHCl3 and hydroxyl stretching frequency shifts of phenol as a proton donor in CCl4 were measured for series of substituted phenyl N,N-dimethylcarbamates (I) and S-phenyl N,N-dimethylthiocarbamates (II).The data
