13511-98-3

Upstream product

• 1950-68-1 4-methoxybenzenesulfonyl hydrazide 
• 68-12-2 N,N-dimethyl-formamide 
• 696-63-9 4-Methoxybenzenethiol 
• 7693-41-6 4-methoxyphenylchloroformate 
• 1122-95-8 sodium 4-methoxyphenolate 
• 150-76-5 4-methoxy-phenol 
• 79-44-7 N,N-Dimethylcarbamoyl chloride 
• 10345-49-0 O-(4-methoxyphenyl) N,N-dimethylcarbamothioate 

Downstream Products

• 5335-87-5 4,4'-dimethoxyphenyl disulfide 
• 3393-77-9 bis(4-methoxyphenyl)sulfide 
• 696-63-9 4-Methoxybenzenethiol 

Relevant academic research and scientific papers

Mechanistic Investigations into the Cation Radical Newman-Kwart Rearrangement

Efforts to elucidate the governing factors in the cation radical Newman-Kwart rearrangement are described. Through a combination of spectroscopic and kinetic analyses, it has been shown that the reactive intermediate is a thione cation radical that has si

Iron(II)/Persulfate Mediated Newman-Kwart Rearrangement

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 yie

Electrochemically Catalyzed Newman-Kwart Rearrangement: Mechanism, Structure-Reactivity Relationship, and Parallels to Photoredox Catalysis

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.

An Electrocatalytic Newman-Kwart-type Rearrangement

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 electrolys

Inverting the Selectivity of the Newman-Kwart Rearrangement via One Electron Oxidation at Room Temperature

The discovery that the Newman-Kwart rearrangement 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 subst

AlCl3-promoted thiolation of acyl C-H bonds with arylsulfonyl hydrazides

AlCl3-promoted thiolation of acyl C-H bonds with arylsulfonyl hydrazides was developed, which represents an effective synthesis of S-aryl thiocarbamates via C-S bond formation reaction.

Ambient-Temperature Newman-Kwart Rearrangement Mediated by Organic Photoredox Catalysis

The Newman-Kwart rearrangement 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 of a commercially available organic single-electron photooxidant. Importantly, this reaction is facilitated at ambient temperatures.

Palladium-catalyzed insertion reactions of isocyanides into thiocarbamates and selenocarbamates

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

Cu(OAc)Catalyzed Thiolation of Acyl C-H bonds with thiols using TBHP as an oxidant

Cu(OAc)promoted TBHP oxidative coupling reaction of formamides with thiols successfully proceeded through direct C-H bond activation of formamides. The corresponding S-phenyl dialkyl thiocarbamate compounds were formed with high yield under solvent-free c

Sintered silicon carbide: A new ceramic vessel material for microwave chemistry in single-mode reactors

Silicon carbide (SiC) is a strongly microwave absorbing chemically inert ceramic material that can be utilized at extremely high temperatures due to its high melting point and very low thermal expansion coefficient. Microwave irradiation induces a flow of electrons in the semiconducting ceramic that heats the material very efficiently through resistance heating mechanisms. The use of SiC carbide reaction vessels in combination with a single-mode microwave reactor provides an almost complete shielding of the contents inside from the electromagnetic field. Therefore, such experiments do not involve electromagnetic field effects on the chemistry, since the semiconducting ceramic vial effectively prevents microwave irradiation from penetrating the reaction mixture. The involvement of electromagnetic field effects (specific/nonthermal microwave effects) on 21 selected chemical transformations was evaluated by comparing the results obtained in microwave-transparent Pyrex vials with experiments performed in SiC vials at the same reaction temperature. For most of the 21 reactions, the outcome in terms of conversion/purity/product yields using the two different vial types was virtually identical, indicating that the electromagnetic field had no direct influence on the reaction pathway. Due to the high chemical resistance of SiC, reactions involving corrosive reagents can be performed without degradation of the vessel material. Examples include high-temperature fluorine-chlorine exchange reactions using triethylamine trihydrofluoride, and the hydrolysis of nitriles with aqueous potassium hydroxide. The unique combination of high microwave absorptivity, thermal conductivity, and effusivity on the one hand, and excellent temperature, pressure and corrosion resistance on the other hand, makes this material ideal for the fabrication of reaction vessels for use in microwave reactors. Simulating conductive heat transfer in a microwave: Using reaction vials made out of strongly microwave-absorbing silicon carbide (SiC) in a microwave reactor simulates a conductively heated autoclave experiment due to efficient shielding of the electromagnetic field by the SiC vial. Advantages of SiC vials for microwave processing include their excellent corrosion resistance, thermal stability, and high thermal effusivity and conductivity.