7305-03-5Relevant 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.
Pd(II) catalyzed ortho C-H iodination of phenylcarbamates at room temperature using cyclic hypervalent iodine reagents
Sun, Xiuyun,Yao, Xia,Zhang, Chao,Rao, Yu
supporting information, p. 10014 - 10017 (2015/06/22)
A novel approach to access ortho iodinated phenols using cyclic hypervalent iodine reagents through palladium(II) catalyzed C-H activation has been developed through weak coordination. The reaction showed excellent regioselectivity, reactivity and good functional group tolerance. A unique mechanism was proposed.
Ligand-assisted copper-catalyzed oxidative cross-coupling of simple phenols with formamides for the synthesis of carbamates
Reddy, Nagireddy Veera,Kumar, Gadde Sathish,Kumar, Pailla Santhosh,Kantam, M. Lakshmi,Reddy, Kallu Rajender
supporting information, p. 2133 - 2138 (2014/11/08)
An oxidative approach for the synthesis of phenyl carbamates has been achieved by ligand-assisted copper-catalyzed cross-dehydrogenative coupling (CDC) of phenols with formamides. The direct coupling of simple phenols with mono- and dialkyl formamides pro
A general approach towards catechol and pyrogallol through ruthenium- and palladium-catalyzed C-H hydroxylation by weak coordination
Yang, Xinglin,Sun, Yonghui,Chen, Zhang,Rao, Yu
supporting information, p. 1625 - 1630 (2014/06/09)
An efficient ruthenium(II)- and palladium(II)-catalyzed C-H hydroxylation of aryl carbamates has been developed for the facile synthesis of catechols and pyrogallols. The reaction demonstrates excellent reactivity, regio- and chemoselectivity, good functional group compatibility and high yields. The practicality of this method has been proved by a gram-scale synthesis.
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
