69173-92-8Relevant academic research and scientific papers
Synthesis of nitrophenyl and fluorophenyl azides and diazides by SNAr under phase-transfer or microwave irradiation: Fast and mild methodologies to prepare photoaffinity labeling, crosslinking, and click chemistry reagents
Leyva, Elisa,Aguilar, Johana,González-Balderas, Regina M.,Vega-Rodríguez, Sarai,Loredo-Carrillo, Silvia E.
, (2020/12/01)
Two fast and mild methodologies to prepare nitrophenyl and fluorophenyl azides are presented. These aryl azides are extensively used as crosslinking, photoaffinity labeling, and click chemistry reagents. Substituted aryl azides are prepared by performing a SNAr substitution on halogenated benzenes with a phase-transfer catalyst (PTC) such as tetraethylammonium tetrafluoroborate (TEATFB), the reaction proceeds in several hours under rather mild temperatures (25°C to 70°C). Furthermore, aryl azides are also prepared within minutes under microwave irradiation at slightly higher temperatures (50°C to 70°C). These procedures could be applied in the preparation of other aryl azides. In the case of substituted pentafluoro benzene (pF), the type of products obtained in each reaction depends on the amount of sodium azide and the strength and position of electron-withdrawing substituents (COH, COR, COOR, CN, NO2, or F). A discussion on the mechanisms and the products obtained in these SNAr reactions is presented.
Iron (III)-porphyrin Complex FeTSPP as an efficient catalyst for synthesis of tetrazole derivatives via [2?+?3]cycloaddition reaction in aqueous medium
El-Remaily, Mahmoud Abd El Aleem Ali Ali,Elhady
, (2019/06/08)
The metal complex (5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin-iron (III) chloride (FeTSPP) was new employed in an environmentally benign protocol as an efficient catalyst for a “click” chemistry approach for the synthesis of tetrazole and guanindinyltetrazole derivatives via [2?+?3] cycloaddition reaction of nitriles and azide derivatives in aqueous medium. The synthesized compounds were obtained in excellent yield, short reaction times and a recoverable catalyst.
Perfluoroaryl Azide Staudinger Reaction: A Fast and Bioorthogonal Reaction
Sundhoro, Madanodaya,Jeon, Seaho,Park, Jaehyeung,Ramstr?m, Olof,Yan, Mingdi
supporting information, p. 12117 - 12121 (2017/09/07)
We report a fast Staudinger reaction between perfluoroaryl azides (PFAAs) and aryl phosphines, which occurs readily under ambient conditions. A rate constant as high as 18 m?1 s?1 was obtained between methyl 4-azido-2,3,5,6-tetrafluorobenzoate and methyl 2-(diphenylphosphanyl)benzoate in CD3CN/D2O. Furthermore, the iminophosphorane product was stable toward hydrolysis and aza-phosphonium ylide reactions. This PFAA Staudinger reaction proved to be an excellent bioothorgonal reaction. PFAA-derivatized mannosamine and galactosamine were successfully transformed into cell-surface glycans and efficiently labeled with phosphine-derivatized fluorophore-conjugated bovine serum albumin.
N, N -diethylurea-catalyzed amidation between electron-deficient aryl azides and phenylacetaldehydes
Xie, Sheng,Ramstr??m, Olof,Yan, Mingdi
supporting information, p. 636 - 639 (2015/03/04)
Urea structures, of which N,N-diethylurea (DEU) proved to be the most efficient, were discovered to catalyze amidation reactions between electron-deficient aryl azides and phenylacetaldehydes. Experimental data support 1,3-dipolar cycloaddition between DEU-activated enols and electrophilic phenyl azides, especially perfluoroaryl azides, followed by rearrangement of the triazoline intermediate. The activation of the aldehyde under near-neutral conditions was of special importance in inhibiting dehydration/aromatization of the triazoline intermediate, thus promoting the rearrangement to form aryl amides.
1,3-Dipolar cycloaddition reactivities of perfluorinated aryl azides with enamines and strained dipolarophiles
Xie, Sheng,Lopez, Steven A.,Ramstr?m, Olof,Yan, Mingdi,Houk
supporting information, p. 2958 - 2966 (2015/03/18)
The reactivities of enamines and predistorted (strained) dipolarophiles toward perfluoroaryl azides (PFAAs) were explored experimentally and computationally. Kinetic analyses indicate that PFAAs undergo (3 + 2) cycloadditions with enamines up to 4 orders of magnitude faster than phenyl azide reacts with these dipolarophiles. DFT calculations were used to identify the origin of this rate acceleration. Orbital interactions between the cycloaddends are larger due to the relatively low-lying LUMO of PFAAs. The triazolines resulting from PFAA-enamine cycloadditions rearrange to amidines at room temperature, while (3 + 2) cycloadditions of enamines and phenyl azide yield stable, isolable triazolines. The 1,3-dipolar cycloadditions of norbornene and DIBAC also show increased reactivity toward PFAAs over phenyl azide but are slower than enamine-azide cycloadditions.
Microwave-assisted synthesis of substituted fluorophenyl mono- and diazides by SNAr. A fast methodology to prepare photoaffinity labeling and crosslinking reagents
Leyva, Elisa,Leyva, Socorro,Moctezuma, Edgar,González-Balderas, Regina M.,De Loera, Denisse
, p. 164 - 169 (2013/11/19)
The reaction of sodium azide with perfluorobenzene, containing an electron-withdrawing group, under microwave irradiation results in the fast preparation of p-substituted tetrafluorophenyl monoazides. Having an excess of sodium azide and a strong electron-withdrawing group like NO2 or CN, fluorophenyl diazides are also produced upon conventional or microwave heating. A synergic effect between the amount of sodium azide and the electron-withdrawing character of the substituents is observed giving different products. A discussion on the products and reaction mechanism is presented.
Facile and Efficient Synthesis of 4-Azidotetrafluoroaniline: A New Photoaffinity Reagent
Chehade, Kareem A. H.,Spielmann, H. Peter
, p. 4949 - 4953 (2007/10/03)
p-Azidotetrafluoroaniline (1) was synthesized in 65-73% yield by two different methods employing a stable carbamate intermediate. The first method trapped the intermediate isocyanate generated via a modified Curtius rearrangement with 2-methyl-2-propanol or 2-(trimethylsilyl)ethanol to form the stable carbamates 2d and 2e, respectively. Benzoic acid 2c was first converted to its acid chloride with PCl5. Displacement of the chloride by NaN3 in acetone/water formed the acyl azide. Thermal rearrangement followed by the addition of the appropriate alcohols provided the carbamates. The acid labile carbamate 2d was deprotected with HCl/AcOH to provide 1, while trifluoroacetic acid was required to deprotect 2e and afford 1. In the second path, 1 was synthesized in five steps from pentafluoronitrobenzene (3a) in 65% overall yield. Compound 3a was converted into 4-azidotetrafluoronitrobenzene (3b) with NaN3 in 93% yield and was used without further purification to form 1,4-diaminotetrafluorobenzene (3c) by Sn/HCl reduction in 85% yield. The mono-9-fiuorenylmethoxycarbonyl (FMOC) derivative 3d was formed from 3c with FMOC-Cl and pyridine in EtOAc in 92% yield. Diazotization of 3d under anhydrous conditions with TFA/NaNO2 and NaN3 gave 3e in 87% yield. The aryl azide was formed with concurrent nitration of the 2-position of the fluorenyl system. The protecting group was removed with piperidine to afford 1 in 93% yield. Irradiation of 1 with 254 nm light in cyclohexane gave cyclohexylamine 11, diamine 3c, and azobenzene 12 as the primary products. The formation of C-H insertion product 11 indicates that 1 forms a singlet nitrene upon photolysis. Two heterobifunctional photoaffinity reagents iodoacetamide 9 and dansyl derivative 10 were prepared.
New Reagents for Photoaffinity Labeling: Synthesis and Photolysis of Functionalized Perfluorophenyl Azides
Keana, John F. W.,Cai, Sui Xiong
, p. 3640 - 3647 (2007/10/02)
Functionalized perfluorophenyl azides (PFPA) 2-6, 8-12, 14-19, and 21-29 were synthesized, allowing the attachment of PFPA to other molecules for application as photolabels.Two biactive molecules were modified by a PFPA as potential photoaffinity labeling reagents.Photolysis of two representative members was investigated.Photolysis of azide 4 in cyclohexane gave 57 percent of CH insertion product.When photolysis was carried out in the presence of diethylamine as a trapping reagent, it gave 65 percent of NH insertion product, and no ring expansion product was found.The nitro azide 19 showed a shoulder absorption in the longer wavelength compared to azide 4.Azide 19 gave less CH insertion and more aniline products compared to azide 4 when photolyzed in toluene, suggesting that the nitro group accelerates intersystem crossing of the singlet nitrene or the singlet excited azide.Collectively, our results demonstrate that the functionalized PFPA investigated are much better in undergoing CH insertion than their nonfluorinated analogues and suggest that they may constitute an improved series of photolabeling reagents.
