7304-69-0Relevant academic research and scientific papers
Visible-light-promoted synthesis of secondary and tertiary thiocarbamates from thiosulfonates andN-substituted formamides
Bi, Wen-Zhu,Zhang, Wen-Jie,Li, Zi-Jie,He, Yuan-Hao,Feng, Su-Xiang,Geng, Yang,Chen, Xiao-Lan,Qu, Ling-Bo
, p. 8701 - 8705 (2021/10/22)
A general visible-light-promoted metal-free synthesis of secondary and tertiary thiocarbamates starting from thiosulfonates andN-substituted formamides is developed. By employing rhodamine B as a photocatalyst andtert-butyl hydroperoxide (TBHP) as an oxidant, a wide scope of thiocarbamates can be obtained through direct thiolation of acyl C-H bonds under irradiation of blue light at room temperature for 12 h.
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.
AlCl3-promoted thiolation of acyl C-H bonds with arylsulfonyl hydrazides
Chen, Jie,Mao, Jincheng,He, Yue,Shi, Daqing,Zou, Binyang,Zhang, Guoqi
supporting information, p. 9496 - 9500 (2015/11/18)
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.
Simulating microwave chemistry in a resistance-heated autoclave made of semiconducting silicon carbide ceramic
Obermayer, David,Damm, Markus,Kappe, C. Oliver
supporting information, p. 15827 - 15830 (2014/04/03)
"Microwave chemistry" without microwaves: A resistance-heated SiC autoclave can effectively mimic the sealed-vessel capabilities, rapid heating and cooling profiles, and excellent process-control features that are inherent to modern microwave reactors. Applied to synthetic chemistry, the ready-to-assemble small device provides identical results as can be obtained in a (costly) microwave system (see figure). Copyright
Cu(OAc)Catalyzed Thiolation of Acyl C-H bonds with thiols using TBHP as an oxidant
Yuan, Yan-Qin,Guo, Sheng-Rong,Xiang, Jian-Nan
supporting information, p. 443 - 448 (2013/03/29)
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
Scale-up of microwave-assisted reactions in a multimode bench-top reactor
Dallinger, Doris,Lehmann, Hansjoerg,Moseley, Jonathan D.,Stadler, Alexander,Kappe, C. Oliver
experimental part, p. 841 - 854 (2012/06/18)
An evaluation of a new bench-top microwave batch reactor that uses a single 1 L reaction vessel is presented. Several microwave-assisted organic reactions have been scaled-up, including Newman Kwart and Diels-Alder reactions, Pd-catalyzed cross-couplings, heterocycle synthesis, aromatic substitution, and a Knoevenagel condensation. A range of different solvents (high and low microwave absorbing), varying reaction times (4 s up to 2 h), and temperatures (120-250 °C) have been explored in these investigations. For all studied transformations, it was possible to perform a direct scale-up (up to 720 mL reaction volume) without changing the previously optimized reaction conditions achieved in a laboratory-scale single-mode microwave instrument (2-20 mL processing volume), obtaining similar isolated product yields. A scalability up to 360-fold, when moving from 3 mmol up to 1.08 mol, was demonstrated, and isolated product yields up to 300 g (2.5 mol scale) in a single run could be accomplished, providing the potential for a kilogram output per day for specific transformations by performing multiple sequential runs.
The Newman-Kwart rearrangement: A microwave kinetic study
Gilday, John P.,Lenden, Philip,Moseley, Jonathan D.,Cox, Brian G.
, p. 3130 - 3134 (2008/09/19)
(Chemical Equation Presented) The kinetic profile of the Newman-Kwart rearrangement has been evaluated using microwave heating. After first demonstrating equivalence between conventional convective heating and microwave heating, data was gathered and anal
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.
Palladium-catalyzed azathiolation of carbon monoxide
Kuniyasu, Hitoshi,Hiraike, Hiroshi,Morita, Masaki,Tanaka, Aoi,Sugoh, Kunihiko,Kurosawa, Hideo
, p. 7305 - 7308 (2007/10/05)
A novel palladium-catalyzed azathiolation of carbon monoxide using sulfenamide (RSNR'2) (1) is described to provide thiocarbamate 2 in good yields. The mechanistic proposal includes the following: (1) insertion of CO into Pd-S bond of Pd(SR)2(PPh3)(n) 4 to provide Pd[C(O)SR](SR)(PPh3)(n) 5 and (2) σ-bond metathesis between S-N and Pd-C(O) bonds to afford 2 with the regeneration of 4.
Rapid and Selective Reduction of Functionalized Aromatic Disulfides with Lithium Tri-tert-butoxyaluminohydride. A Remarkable Steric and Electronic Control. Comparison of Various Hydride Reagents
Krishnamurthy, S.,Aimino, D.
, p. 4458 - 4462 (2007/10/02)
Lithium tri-tert-butoxyaluminohydride (LTBA), an exceptionally mild reducing agent in organic synthesis, reduces functionalized aromatic disulfides to the corresponding thiols in quantitative yield.The reaction is rapid (for example, o-tolyl disulfide is reduced to completion in 60 min at 25 deg C) and can tolerate a wide variety of functional groups, such as halogen, nitro, carboxylic acid, and their derivatives.The presence of electron-withdrawing substituents dramatically enhances the rate of reduction (p-chlorophenyl disulfide is quantitatively reduced in 30 s) and electron-releasing substituents diminishes the rate of cleavage.The reaction is sensitive to steric effects (2,4-di-tert-pentylphenyl disulfide underwent 25percent reduction in 24 h).However, such hindered disulfides can be rapidly and quantitatively reduced in refluxing THF.The reaction of LTBA with alkyl disulfides is extremely sluggish.The reaction provides a useful and simple means for the facile and selective reduction of aromatic disulfides where this is required in synthetic operations.
