19188-18-2Relevant academic research and scientific papers
Long Vibrational Lifetime R-Selenocyanate Probes for Ultrafast Infrared Spectroscopy: Properties and Synthesis
Daniels, Robert,Fayer, Michael D.,Fica-Contreras, Sebastian M.,Hoffman, David J.,Pan, Junkun,Sotzing, Gregory,Yassin, Omer
, p. 8907 - 8918 (2021/08/23)
Ultrafast infrared vibrational spectroscopy is widely used for the investigation of dynamics in systems from water to model membranes. Because the experimental observation window is limited to a few times the probe's vibrational lifetime, a frequent obstacle for the measurement of a broad time range is short molecular vibrational lifetimes (typically a few to tens of picoseconds). Five new long-lifetime aromatic selenocyanate vibrational probes have been synthesized and their vibrational properties characterized. These probes are compared to commercial phenyl selenocyanate. The vibrational lifetimes range between 400 and 500 ps in complex solvents, which are some of the longest room-temperature vibrational lifetimes reported to date. In contrast to vibrations that are long-lived in simple solvents such as CCl4, but become much shorter in complex solvents, the probes discussed here have ～400 ps lifetimes in complex solvents and even longer in simple solvents. One of them has a remarkable lifetime of 1235 ps in CCl4. These probes have a range of molecular sizes and geometries that can make them useful for placement into different complex materials due to steric reasons, and some of them have functionalities that enable their synthetic incorporation into larger molecules, such as industrial polymers. We investigated the effect of a range of electron-donating and electron-withdrawing para-substituents on the vibrational properties of the CN stretch. The probes have a solvent-independent linear relationship to the Hammett substituent parameter when evaluated with respect to the CN vibrational frequency and the ipso 13C NMR chemical shift.
Synthesis of Monofluoromethyl Selenoethers of Aryl and Alkyl from Organoselenocyanate via One-Pot Reaction
Cao, Yuan,Jiang, Lvqi,Yi, Wenbin
supporting information, p. 4360 - 4368 (2019/08/01)
The first practical and feasible approach for the monofluoromethylselenolation of aryl and alkyl halides via one-pot multistep synthesis using KSeCN and ICFH2 is described. Good yields and broad functional group compatibility were obtained. The successful preparation of monofluoromethylselenolated drug-like compounds good practicability of this method. This protocol offered a number of new monofluoromethyl selenoethers, which would accelerate the use of such compounds in the areas of life science. (Figure presented.).
A convenient, transition metal-free synthesis of difluoromethyl selenoethers from organic selenocyanates and TMSCF2H
Dong, Tao,Nie, Jing,Zhang, Cheng-Pan
, p. 5642 - 5649 (2018/08/22)
An efficient and transition metal-free method for the synthesis of aryl or alkyl difluoromethyl selenides (RSeCF2H) from the corresponding selenocyanates (RSeCN) and TMSCF2H/t-BuOK is described. The reaction performed in THF at 0 °C for 24 h or at room temperature for 6 h supplied a series of RSeCF2H in good to high yields. The successful preparation of difluoromethylselenolated sulfadimethoxine derivative and the scaled-up synthesis of 1-benzyl-5-((difluoromethyl)selanyl)indoline, as examples, suggested good practicability of this method. Advantages of the reaction include mild reaction conditions, good functional group tolerance, a wide range of substrates, and high efficiency. This protocol offered a number of novel difluoromethyl selenoethers, which would accelerate use of such compounds in the areas of life science.
Metal-free synthesis of unsymmetrical organoselenides and selenoglycosides
Guan, Yong,Townsend, Steven D.
supporting information, p. 5252 - 5255 (2017/11/06)
A one-pot, metal-free procedure has been developed to synthesize unsymmetrical organoselenides. In the first step of the reaction, arylation of potassium selenocyanate (KSeCN) with an iodonium reagent proceeds in the absence of a metal catalyst to produce
Trifluoromethylselenolation of Aryldiazonium Salts: A Mild and Convenient Copper-Catalyzed Procedure for the Introduction of the SeCF3 Group
Nikolaienko, Pavlo,Rueping, Magnus
supporting information, p. 2620 - 2623 (2016/02/27)
The straightforward introduction of the trifluoromethylseleno group into aromatic and heteroaromatic compounds is accomplished by the utilization of readily available aryldiazonium tetrafluoroborates, potassium selenocyanate, and Ruppert-Prakash reagent. The reaction tolerates a wide range of aromatic and heteroaromatic diazonium salts and is also amenable to the synthesis of pentafluoroethyl selenoethers. Furthermore, the methodology can be applied directly starting from anilines.
Electrophilic organic selenium reagents - Protonated seleninic acids as precursors for unsymmetrical aromatic selenides
Stuhr-Hansen, Nicolai,S?lling, Theis Ivan,Henriksen, Lars
scheme or table, p. 2633 - 2643 (2011/04/25)
Arylselenylations of methylbenzenes, methoxybenzenes and thiophene were smoothly achieved with selenenium ions generated by comproportionation of 1:1 mixtures of p-toluenesulfonic acid salts of seleninic acids and the corresponding diselenides. A series of p-toluenesulfonic salts of seleninic acids were prepared by hydrogen peroxide oxidation of the corresponding diselenides in the presence of p-toluenesulfonic acid. Novel 2-(organylseleno)thiophenes were obtained by heating the protonated seleninic acids with a 50-fold excess of thiophene in glacial acetic acid.
Synthesis of novel 5-aryl-1H-tetrazoles
Oezkan, Hamdi,Yavuz, Serkan,Disli, Ali,Yildirir, Yilmaz,Tuerker, Lemi
, p. 255 - 258 (2008/02/08)
In this study phenylselenocyanate and some of its derivatives (o-Cl, p-Cl, p-Br, o-NO2, p-NO2, o-CH3, p-CH3, o-COOH, p-COOH, p-OCH3 substituted) were synthesized (3a-3j). The synthesized compounds were converted to 5-aryl-1H-tetrazole (4a-4j), by Et 3N · HCl-NaN3 in toluene, which are a new series of phenylselanyl-1H-tetrazoles. The structure of all the presently synthesized compounds were confirmed using spectroscopic methods (FTIR, 1H NMR, MS).
Reaction of Areneselenyl Chlorides and alkenes. An example of Nucleophilic Displacement at Bivalent Selenium
Schmid, George H.,Garratt, Dennis G.
, p. 4169 - 4172 (2007/10/02)
The effect of substituents in the phenyl ring of both the electrophile and the alkene has been studied in the reaction of areneselenyl chlorides and (E)- and (Z)-1-phenylpropenes.Electron-donating groups in both phenyl rings enhance the rate of reaction.Viewing this reaction as a nucleophilic displacement at bivalent selenium leads to a model that allows the possibility of reaction by a continuum of mechanisms.These mechanisms differ only in the relative amounts of C-Se bond making and Se-Cl bond breaking in the rate-determining transition state.From our data, it is concluded that C-Se bond making lags behind Se-Cl bond breaking in the rate determining transition state.
