- Rh2(II)-Catalyzed intermolecular N-Aryl aziridination of olefins using nonactivated N atom precursors
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The development of the first intermolecular Rh2(II)-catalyzed aziridination of olefins using anilines as nonactivated N atom precursors and an iodine(III) reagent as the stoichiometric oxidant is reported. This reaction requires the transfer of an N-aryl nitrene fragment from the iminoiodinane intermediate to a Rh2(II) carboxylate catalyst; in the absence of a catalyst only diaryldiazene formation was observed. This N-aryl aziridination is general and can be successfully realized by using as little as 1 equiv of the olefin. Di-, tri-, and tetrasubstituted cyclic or acylic olefins can be employed as substrates, and a range of aniline and heteroarylamine N atom precursors are tolerated. The Rh2(II)-catalyzed N atom transfer to the olefin is stereospecific as well as chemo- and diastereoselective to produce the N-aryl aziridine as the only amination product. Because the chemistry of nonactivated N-aryl aziridines is underexplored, the reactivity of N-aryl aziridines was explored toward a range of nucleophiles to stereoselectively access privileged 1,2-stereodiads unavailable from epoxides, and removal of the N-2,4-dinitrophenyl group was demonstrated to show that functionalized primary amines can be constructed.
- Deng, Tianning,Mazumdar, Wrickban,Yoshinaga, Yuki,Patel, Pooja B.,Malo, Dana,Malo, Tala,Wink, Donald J.,Driver, Tom G.
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p. 19149 - 19159
(2021/11/23)
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- Iron (III)-porphyrin Complex FeTSPP as an efficient catalyst for synthesis of tetrazole derivatives via [2?+?3]cycloaddition reaction in aqueous medium
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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.
- El-Remaily, Mahmoud Abd El Aleem Ali Ali,Elhady
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- A Potent Halogen-Bonding Donor Motif for Anion Recognition and Anion Template Mechanical Bond Synthesis
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The covalent attachment of electron deficient perfluoroaryl substituents to a bis-iodotriazole pyridinium group produces a remarkably potent halogen bonding donor motif for anion recognition in aqueous media. Such a motif also establishes halogen bonding anion templation as a highly efficient method for constructing a mechanically interlocked molecule in unprecedented near quantitative yield. The resulting bis-perfluoroaryl substituted iodotriazole pyridinium axle containing halogen bonding [2]rotaxane host exhibits exceptionally strong halide binding affinities in competitive 50 % water containing aqueous media, by a factor of at least three orders of magnitude greater in comparison to a hydrogen bonding rotaxane host analogue. These observations further champion and advance halogen bonding as a powerful tool for recognizing anions in aqueous media.
- Bunchuay, Thanthapatra,Docker, Andrew,Martinez-Martinez, Antonio J.,Beer, Paul D.
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p. 13823 - 13827
(2019/08/22)
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- Facile fabrication of branched-chain carbohydrate chips for studying carbohydrate-protein interactions by QCM biosensor
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A novel approach for fabricating branched-chain (BC) carbohydrate chips to study carbohydrate-protein interactions using Quartz Crystal Microbalance (QCM) biosensor was developed. This approach utilizes functional alkynyl-branch molecule modified chip surfaces, which through the terminal alkynyl group for covalent linking of unprotected azide-carbohydrates. The unprotected azide-carbohydrates were syhthesized in one-step using 2-azido-1,3-dimethyl-imidazolinium as catalyst, avoiding complex chemical modifications. Additionally, the branch surface modified with the carbohydrates not only supplies more specific binding site but also reveals significant cluster effect. To exemplify the sugar cluster effect on BC carbohydrate chips, BC Galactose and Mannose chips prepared in this work were used to determine carbohydrate-lectin interactions using QCM biosensor. The results clearly showed that BC chip significantly improves the detection sensitivity compared with the straight-chain (SC) chip. More importantly, the BC galactose chip sensitivity was enhanced 40% compared with the SC galactose chip.
- Lu, Yuchao,Song, Siyu,Hou, Chenxi,Pang, Shuang,Li, Xueming,Wu, Xiaowen,Shao, Chen,Pei, Yuxin,Pei, Zhichao
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- COMPOSITIONS AND METHODS OF CERENKOV TARGETED AND ACTIVATED IMAGING AND THERAPEUTICS
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Described herein are compositions and methods that confine Cerenkov light to a localized area for targeted treatment and/or imaging of tumor cells. In certain embodiments, such compositions include a Cerenkov-activated tagging agent comprising a payload and a covalent binding unit such as an azide. The payload can be an imaging agent, a contrast agent, and/or a therapeutic. In certain embodiments, a radiolabelled biomarker (e.g., 18F-FDG (fluorodeoxyglucose), 18F-FLT (fluorothymidine)) or other radiolabelled tumor cell targeting agent that emits Cerenkov luminescence is also administered. Upon local illumination by the Cerenkov luminescence at or near the location of the tumor cells, the payload (the imaging agent, contrast agent, and/or therapeutic) is activated. In this way, activation of the imaging agent, contrast agent, and/or therapeutic agent is limited to the region at or near the location of the tumor cells.
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Paragraph 0138
(2017/02/24)
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- Universal Scalable and Cost-Effective Surface Modifications
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Disclosed are fouling resistant filtration membranes comprising a polymeric thin-film membrane comprising a surface. Also disclosed are methods of modifying thin-film filtration membranes, thereby improving, for example, the anti-fouling properties of the membranes. Also disclosed are methods of purifying water using the disclosed membranes. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.
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- Design and synthesis of peptide conjugates of phosphoramide mustard as prodrugs activated by prostate-specific antigen
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A series of Glutaryl-Hyp-Ala-Ser-Chg-Gln-4-aminobenzyl phosphoramide mustard conjugates (1a-e) was designed and synthesized as potential prodrugs for site-specific activation by PSA in prostate cancer cells. All conjugates were found to be substrates of PSA with cleavage occurring between Gln and the para-aminobenzyl (PAB) linker. Structure-activity relationship studies on these conjugates indicated that introduction of electron-withdrawing fluorine(s) on the phenyl ring in the PAB linker uniformly improved the chemical stability of the conjugates while the position of substitution affected differently the self-immolative process of conjugates upon proteolysis. Introduction of a fluorine at ortho position to benzylic phosphoramide as in 1b results in better stability of the conjugate prior to activation while maintaining its antiproliferative activity upon activation by PSA. The conjugate 1b with 2-fluoro substitution was identified as a promising lead for further evaluation and optimization in the development of prostate cancer-targeted prodrugs.
- Wu, Xinghua,Hu, Longqin
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p. 2697 - 2706
(2016/06/08)
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- A general method for the fabrication of graphene-nanoparticle hybrid material
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We describe a simple and general approach to conjugate nanoparticles on pristine graphene. The method takes advantage of the high reactivity of perfluorophenyl nitrene towards the C=C bonds in graphene, where perfluorophenyl azide-functionalized nanoparticles are conjugated to pristine graphene through the [2+1] cycloaddition reaction by a fast photoactivation.
- Park, Jaehyeung,Jayawardena, H. Surangi N.,Chen, Xuan,Jayawardana, Kalana W.,Sundhoro, Madanodaya,Ada, Earl,Yan, Mingdi
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p. 2882 - 2885
(2015/03/05)
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- Unique Separation Behavior of a C60 Fullerene-Bonded Silica Monolith Prepared by an Effective Thermal Coupling Agent
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Herein, we report a newly developed C60 fullerene-bonded silica monolith in a capillary with unique retention behavior due to the structure of C60 fullerene. N-Hydroxysuccinimide (NHS)-conjugated C60 fullerene was successfully synthesized by a thermal coupling agent, perfluorophenyl azide (PFPA), and assigned by spectroscopic analyses. Then, NHS-PFPA-C60 fullerene was attached onto the surface of a silica monolith in a capillary. The capillary provided specific separation ability for polycyclic aromatic hydrocarbons in liquid chromatography by an effective π-π interaction. Furthermore, corannulene, which has a hemispherical structure, was selectively retained in the capillary based on the specific structural recognition due to the spherical C60 fullerene. This is the first report revealing the spherical recognition ability by C60 fullerene in liquid chromatographic separation. Spherical recognition: A C60 fullerene-bonded silica monolithic medium was prepared by using a thermal coupling agent conjugated with C60 fullerene. The C60 fullerene-bonded monolith prepared in a capillary showed a very strong π-π interaction in liquid chromatography. Also, the hemispherical molecule corannulene was dramatically retained in the C60 fullerene-bonded monolith by the unique molecular recognition based on a buckyball (see figure).
- Kubo, Takuya,Murakami, Yoshiki,Tsuzuki, Madoka,Kobayashi, Hiroshi,Naito, Toyohiro,Sano, Tomoharu,Yan, Mingdi,Otsuka, Koji
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p. 18095 - 18098
(2015/12/24)
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- Towards a biocompatible artificial lung: Covalent functionalization of poly(4-methylpent-1-ene) (TPX) with cRGD pentapeptide
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Covalent multistep coating of poly(methylpentene), the membrane material in lung ventilators, by using a copper-free "click" approach with a modified cyclic RGD peptide, leads to a highly biocompatible poly(methylpentene) surface. The resulting modified membrane preserves the required excellent gas-flow properties while being densely seeded with lung endothelial cells.
- Moeller, Lena,Hess, Christian,Palecek, Jiri,Su, Yi,Haverich, Axel,Kirschning, Andreas,Draeger, Gerald
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p. 270 - 277
(2013/04/10)
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- Polyurethane (PU)-derived photoactive and copper-free clickable surface based on perfluorophenyl azide (PFPA) chemistry
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The anchoring and capturing roles of perfluorophenyl azide (PFPA) were combined to produce a universal polyurethane (PU)-derived photoactive surface platform (PU-1-PFPA). The resultant platform was confirmed by contact angle, attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) analyses. Upon UV light activation, native heparin was coupled directly onto PU-1-PFPA to yield a substrate with antithrombogenic properties. The same level of antithrombogenic activity was achieved when the recovered heparin was photo-coupled onto PU-1-PFPA. In addition, at room temperature and in the absence of copper catalysts, PU-1-PFPA achieved oriented immobilization of functional moieties bearing an alkynyl functional group.
- Li, Lingdong,Li, Jiang,Kulkarni, Abhilash,Liu, Song
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p. 571 - 582
(2013/06/26)
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- Tri- and tetravalent photoactivable cross-linking agents
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A modular synthesis of photoactivable cross-linking agents is described, using an aromatic core, di- or triethyleneglycol spacers and photoaffinity labeling synthons that feature either perfluorophenyl azide or aryl(trifluoromethyl)diazirine motifs. Symmetrical and nonsymmetrical trivalent structures were obtained from phloroglucinol and dopamine, respectively. Symmetrical tetravalent structures resulted from the coupling of two dopamine derivatives with oxalyl chloride. Georg Thieme Verlag Stuttgart New York.
- Welle, Alexandre,Billard, Francois,Marchand-Brynaert, Jacqueline
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p. 2249 - 2254
(2012/10/08)
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- Aryl azide based, photochemical patterning of cyclic olefin copolymer surfaces with non-biofouling poly[(3-(methacryloylamino)propyl)dimethyl(3- sulfopropyl)ammonium hydroxide]
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Micropatterns of cells were generated on a cyclic olefin copolymer (COC) by a combination of aryl-azide-based photopatterning of a polymerization initiator and surface-initiated atom-transfer radical polymerization of non-biofouling 3-(methacryloylamino)propyl)-dimethyl(3-sulfopropyl)ammonium hydroxide (MPDSAH). The optical transparency of the COC made it possible to generate the patterns indirectly through a COC slab. Copyright
- Kim, Jinkyu,Hong, Daewha,Jeong, Seungpyo,Kong, Bokyung,Kang, Sung Min,Kim, Yang-Gyun,Choi, Insung S.
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p. 363 - 366
(2011/10/12)
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- Method for functionalizing materials and devices comprising such materials
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Devices comprising functionalized materials, and embodiments of a method for making and using such devices, are disclosed. Exemplary devices include ophthalmic devices, nanoparticles, quartz crystal microbalances, microarrays, and nanocomposites. In particular embodiments, device surfaces are modified with monomers and/or polymers, typically carbohydrate monomers and/or polymers. Embodiments of a method for making and using such devices are disclosed. Monomers and/or polymers are covalently bonded to surfaces using functionalized perhalophenylazides. In some embodiments, device surfaces are functionalized with a perhalophenylazide. One or more monomers and/or polymers subsequently are covalently bonded to the device surface using the perhalophenylazide. In other embodiments, monomers and/or polymers are derivatized with a functionalized perhalophenylazide. The derivatized monomers and/or polymers then are covalently bonded to the device surface using the perhalophenylazide. In some embodiments, graphite is functionalized with perhalophenylazide to produce a functionalized graphene sheet. In other embodiments, graphene sheets are covalently attached to functionalized substrates.
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- exo-N-[2-(4-Azido-2,3,5,6-tetrafluorobenzamido)ethyl]-dC: a novel intermediate in the synthesis of dCTP derivatives for photoaffinity labelling
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An alternative route for the synthesis of a photoaffinity labelling (PAL) dCTP derivative is reported. This method involves the intermediacy of exo-N-[2-(4-azido-2,3,5,6-tetrafluorobenzamido)ethyl]-dC. The latter is prepared from the coupling of known N-(2-aminoethyl)-4-azido-2,3,5,6-tetrafluorobenzamide, prepared in an improved three-step sequence, with an activated 4-triazolyl derivative of dU, followed by deprotection. 19F NMR spectroscopy proved extremely useful in following the synthetic transformations, and enabled control of any adventitious reduction of the azides.
- Cisma?, Crina,Gimisis, Thanasis
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p. 1336 - 1339
(2008/09/18)
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- Synthesis and characterization of photolabeling probes of miltefosine
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Miltefosine is an ether-phospholipid analogue showing remarkable anti-cancer and anti-leishmanial activity thanks to its cell membrane-targeting properties. In order to study the mechanisms responsible for the biological effects of miltefosine using a photolabeling approach, we designed, synthesized and characterized photolabeling probes for studying the effects of miltefosine. In these probes, the photoactivatable tetrafluorophenylazido group is incorporated either at the polar head or in the alkyl chain of miltefosine. The probes showed fast, clear-cut photochemical reactions, which suggests that they are promising tools for use in photolabeling studies.
- Huang, Fei,Qu, Fanqi,Peng, Qing,Xia, Yi,Peng, Ling
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p. 739 - 743
(2007/10/03)
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- Tetrafluoroazidoaniline and method of making and using the same
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The invention is directed to a novel compounds comprising 4-azidotetrafluoroaniline and the alkyl, acyl and sulfonamide derivatives thereof and to methods of making and using the same. The novel compounds are useful as a photoaffinity probe to study protein structure and function. Two methods for preparing 4-azidotetrafluoroaniline are disclosed, each employing a stable carbamate intermediate from which the 4-azidotetrafluoroaniline is derived.
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- Facile and Efficient Synthesis of 4-Azidotetrafluoroaniline: A New Photoaffinity Reagent
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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.
- Chehade, Kareem A. H.,Spielmann, H. Peter
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p. 4949 - 4953
(2007/10/03)
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- Unusually Long Lifetimes of the Singlet Derived from 4-Azido-2,3,5,6-tetrafluorobenzamides
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Laser flash photolysis (308 nm, 20 ns, 150 mJ) of 4-azido-2,3,5,6-tetrafluorobenzamides, esters, and thioesters generate singlet nitrenes which can be intercepted with pyridine to produce strongly absorbing ylides.It was possible to resolve the rate of formation of the ylides as a function of pyridine concentration.This has lad to direct measurements of the absolute rate constants of (a) the reaction of the nitrene with pyridine, (b) ring expansion of the nitrene to a ketenimine, and (c) singlet to triplet nitrene intersystem crossing.
- Marcinek, Andrzej,Platz, Matthew S.,Chan, Stephen Y.,Floresca, Rey,Rajagopalan, Krishnan,et al.
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p. 412 - 419
(2007/10/02)
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- Synthesis of a Tetrafluoro-Substituted Aryl Azide and Its Protio Analogue as Photoaffinity Labeling Reagents for the Estrogen Receptor
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A tetrafluoro-substituted aryl azide 1 and its protio analogue 2, both photoaffinity labeling reagents for the estrogen receptor, have been prepared by direct coupling of the appropriately substituted 4-azidobenzoyl chloride with the electron rich C-3 of 6-methoxy-2-(4-methoxyphenyl)benzothiophene 3.This represents a rare example of aryl azide stability under Friedel-Crafts acylation conditions.Alternatively, the protio analogue 2 can also be prepared with the azide functionality masked as a phthaloyl-protected arylamine, and the tetrafluoro analogue 1, by direct displacement of a pentafluoroaryl derivative 20 with NaN3.Solution photolysis of tetrafluoro-substituted aryl azide (bis-methyl ether) 15 and its protio analogue 16 in toluene at 30 deg C results in relatively high yields of products derived from C-H insertion.Both azides 1 and 2 demonstrate favorable relative binding affinity (RBA) (1 = 10percent, 2 = 66percent, estradiol = 100percent) and photoinactivation efficiency (1 = 43percent, 2 = 55percent at 30 min) for the estrogen receptor (ER).The synthesis of both azides has been modified to accommodate a palladium-catalyzed tritium gas hydrogenolysis of an iodoaryl precursor at a late stage in the synthetic sequence, as will be needed to prepare them in radiolabeled form, and this procedure has been verified dy deuteration.This pair of compounds will allow a detailed evaluation of the role that fluorine substitution plays in the photochemistry and photocovalent attachment behavior of aryl azides in a complex biochemical system, the estrogen receptor.The radiosynthesis and further biochemical results will be presented elsewhere.
- Pinney, Kevin G.,Katzenellenbogen, John A.
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p. 3125 - 3133
(2007/10/02)
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- New Reagents for Photoaffinity Labeling: Synthesis and Photolysis of Functionalized Perfluorophenyl Azides
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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.
- Keana, John F. W.,Cai, Sui Xiong
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p. 3640 - 3647
(2007/10/02)
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- FUNCTIONALIZED PERFLUOROPHENYL AZIDES. NEW REAGENTS FOR PHOTOAFFINITY LABELING
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Several substituted perfluorophenyl azides capable of attachement to other molecules by an acylation reaction were synthesized for use as photoaffinity labeling reagents.
- Keana, John W.,Cai,Sui Xiong
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p. 151 - 154
(2007/10/02)
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