cas 4165-60-0, NITROBENZENE-D5 | Articles data

Articles about 4165-60-0Total 28 be found

Article title
Article abstract
Author
Journal number and time
Download

Gold(I)-Catalyzed Oxidative 1,4-Additions of 3-En-1-ynamide with Nitrones via Carbon- versus Nitrogen-Addition Chemoselectivity
This work reports gold-catalyzed 1,4-oxofunctionalizations of 3-en-1-ynamides with nitrones, yielding two distinct E-configured products. We obtained 1,4-oxoarylation products from 3-en-1-ynamides bearing C(4)-electron-donating substituents and 1,4-oxoamination products from those analogues bearing C(4)-aryl substituents. We propose that if vinylgold carbenes are stable, imines undergo a para-arylation on these gold carbenes. If vinylgold carbenes are highly electron-deficient, this N-attack is irreversible to enable 1,4-oxoaminations.
Tanpure, Sudhakar Dattatray,Kale, Balaji S.,Liu, Rai-Shung
supporting information
p. 1394 - 1399
(2021/02/20)

Synthesis of Unprotected and Highly Substituted Indoles by the Ruthenium(II)-Catalyzed Reaction of Phenyl Isocyanates with Diaryl/Diheteroaryl Alkynes/Ethyl-3-phenyl Propiolates
A one-pot transformation has been developed for the synthesis of unprotected and highly substituted indoles by an in situ installed carbamide-directed Ru(II)-catalyzed intermolecular oxidative annulation of phenyl isocyanates with diaryl/diheteroaryl alkynes/ethyl phenyl propiolates in the presence of Cu(OAc)2·H2O as an oxidant and AgSbF6 as an additive at 120 °C within 3 h.
Kumar, Amrendra,Tadigoppula, Narender
supporting information
p. 8 - 12
(2021/01/13)

Benzocarbazole Synthesis via Visible-Light-Accelerated Rh(III)-Catalyzed C-H Annulation of Aromatic Amines with Bicyclic Alkenes
A visible-light-accelerated Rh(III)-catalyzed C-H annulation of aromatic amines with bicyclic alkenes for the synthesis of benzocarbazole derivatives was developed. In this approach, with the cooperation of rhodium catalysis and visible-light irradiation, various aromatic amines reacted with oxabicyclic alkenes and azabicyclic alkenes smoothly at room temperature, delivering the corresponding bridged oxa or aza tetrahydro benzocarbazoles in good to excellent yields. Moreover, a series of benzo[b]carbazoles were synthesized conveniently through further aromatization in one pot. The potential of this method was demonstrated via directing-group removal, derivatization, a scale-up reaction, and fluorescence investigations.
Wang, Yichun,Jia, Deyang,Zeng, Jing,Liu, Yuming,Bu, Xiubin,Yang, Xiaobo
supporting information
p. 7740 - 7745
(2021/10/20)

Copper-Catalyzed Modular Access to N-Fused Polycyclic Indoles and 5-Aroyl-pyrrol-2-ones via Intramolecular N—H/C—H Annulation with Alkynes: Scope and Mechanism Probes
Copper-catalyzed intramolecular N—H/C—H annulation with alkynes has been developed. A variety of densely functionalized heterocycles, such as pyrrolo[1,2-a]indoles, indolo[1,2-c]quinazolin-2-ones, oxazolo[3,4-a]indoles, and imidazo[1,5-a]indoles, were synthesized in an atom- and step-economical manner, owing to the high modularized feature of aniline moiety, the linker moiety, as well as the alkyne moiety. By simply changing the oxidant from di-tert-butyl peroxide (DTBP) to 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), the reaction could readily be transformed to the aminooxygenation pathway, which grabs one oxygen atom from the TEMPO to generate 5-aroyl-pyrrol-2-ones. Mechanistic experiments indicate that vinyl radical is involved in this reaction and an amidyl-radical-initiated radical cascade might be responsible for this transformation.
Liu, Yan-Hua,Song, Hong,Zhang, Chi,Liu, Yue-Jin,Shi, Bing-Feng
supporting information
p. 1545 - 1552
(2020/09/09)

A New Class of Lanthanide Complexes with Three Ligand Centered Radicals: NMR Evaluation of Ligand Field Energy Splitting and Magnetic Coupling
Combination of three radical anionic Ph-BIAN ligands (Ph-BIAN=bis-(phenylimino)-acenaphthenequinone) with lanthanoid ions leads to a series of homoleptic, six-coordinate complexes of the type Ln(Ph-BIAN)3. Magnetic coupling data were measured by paramagnetic solution NMR spectroscopy. Combining 1H NMR with 2H NMR of partially deuterated compounds allowed a detailed study of the magnetic susceptibility anisotropies over a large temperature range. The observed chemical shifts were separated into ligand- and metal-centered contributions by comparison with the Y analogue (diamagnetic at the metal). The metal-centered contributions of the complexes with the paramagnetic ions could then be separated into pseudocontact and Fermi contact shifts. The latter is large within the Ph-BIAN scaffold, which shows that magnetic coupling is significant between the lanthanide ion and the radical ligand. Pseudocontact shifts were further correlated to structural data obtained from X-ray diffraction experiments. Ligand-field parameters were determined by fitting the temperature dependence of the observed magnetic susceptibility anisotropies. The electronic structure determined by this approach shows, that the Er and Tm analogues are candidates for single molecule magnets (SMM). These results demonstrate the possibilities for the application of NMR spectroscopy in investigations of paramagnetic systems in general and single molecule magnets in particular.
Hiller, Markus,Sittel, Thomas,Wadepohl, Hubert,Enders, Markus
supporting information
p. 10668 - 10677
(2019/07/12)

Halogenated anilines as novel natural products from a marine biofilm forming microalga
The toxic halogenated anilines 2,4,6-tribromoaniline, 2,4,6-trichloroaniline and their dibromochloro and bromodichloro derivatives were considered as compounds of exclusive synthetic origin. Labeling studies and kinetic experiments confirmed that these substances are also biosynthesized by a marine biofilm forming microalga. They represent a novel class of halogenated natural products.
Baumeister, Tim U. H.,Staudinger, Mona,Wirgenings, Marino,Pohnert, Georg
p. 11948 - 11951
(2019/10/14)

Exogenous Photosensitizer-, Metal-, and Base-Free Visible-Light-Promoted C-H Thiolation via Reverse Hydrogen Atom Transfer
Visible-light-driven, intramolecular C(sp2)-H thiolation has been achieved without addition of a photosensitizer, metal catalyst, or base. This reaction induces the cyclization of thiobenzanilides to benzothiazoles. The substrate absorbs visible light, and its excited state undergoes a reverse hydrogen-atom transfer (RHAT) with 2,2,6,6-tetramethylpiperidine N-oxyl to form a sulfur radical. The addition of the sulfur radical to the benzene ring gives an aryl radical, which then rearomatizes to benzothiazole via RHAT.
Xu, Ze-Ming,Li, Hong-Xi,Young, David James,Zhu, Da-Liang,Li, Hai-Yan,Lang, Jian-Ping
supporting information
p. 237 - 241
(2019/01/10)

Ruthenium(II)-Catalyzed Oxidative Double C-H Activation and Annulation Reaction: Synthesis of Indolo[2,1- a]isoquinolines
The first metal-catalyzed double aryl C(sp2)-H bond activation of antipyrine and alkyne annulation reaction is reported. This Ru(II)-catalyzed reaction was accomplished in the presence of 20 mol % phosphine ligand tricyclohexylphosphine tetrafluoroborate to afford indolo[2,1-a]isoquinolines that are very important compounds because of their bioactivity and interesting optical properties.
Borthakur, Somadrita,Sarma, Bipul,Gogoi, Sanjib
supporting information
p. 7878 - 7882
(2019/10/11)

Stable isotope deuterium labeled sulfanilamide drug and preparation method thereof
The invention belongs to the technical field of chemical synthesis, and specifically relates to a stable isotope deuterium labeled sulfanilamide drug and a preparation method thereof. The preparationmethod comprises the following steps: (1) subjecting benzene-d6 (I) to a nitratlon reaction so as to prepare deuterium labeled nitrobenzene-d5 (II); (2) reducing nitro of the deuterium labeled nitrobenzene-d5 (II) so as to prepare deuterium labeled aniline-d5 (III); (3) under the conditions of anhydrous sodium acetate and glacial acetic acid, subjecting the deuterium labeled aniline-d5 (III) and acetic anhydride to a reaction so as to prepare deuterium labeled N-acetanilide-d5 (IV); (4) subjecting the deuterium labeled N-acetanilide-d5 (IV) and chlorosulfonic acid to a reaction so as to prepare deuterium labeled 1-chlorosulfonyl-4-acetamidobenzene-d4 (V); and (5) allowing R to substitute chlorine of the deuterium labeled 1-chlorosulfonyl-4-acetamidobenzene-d4 (V), and carrying out hydrolysis so as to prepare an isotope deuterium labeled sulfanilamide drug (VII). The preparation method provided by the invention has the advantages of simple reaction conditions, short reaction time, highconversion efficiency, strong economy, and applicability to mass synthesis.
-
Paragraph 0026; 0027; 0028; 0029

(2018/04/26)

Ru(II)-Catalyzed C-H Activation and Annulation Reaction via Carbon-Carbon Triple Bond Cleavage
An unprecedented Ru(II)-catalyzed C-H activation and annulation reaction, which proceeds via C-C triple bond cleavage, is reported. This reaction of 2-phenyldihydrophthalazinediones with alkynes, which works most efficiently in the presence of bidented ligand 1,3-bis(diphenylphosphino)propane, affords good yields of substituted quinazolines.
Prakash, Rashmi,Bora, Bidisha R.,Boruah, Romesh C.,Gogoi, Sanjib
supporting information
p. 2297 - 2300
(2018/04/30)

Ru(II)-Catalyzed and Ligand-Controlled C-H Activation and Annulation via 1,2-Phenyl Shift: Synthesis of Quaternary Carbon-Centered Pyrimidoindolones
A novel Ru(II)-catalyzed C-H activation and annulation reaction of N-arylpyrazol-5-ones and diaryl/arylalkyl-substituted alkynes is developed. Unlike the reported metal-catalyzed C-H activation and annulation reactions, in the present bidentate amine-ligand controlled C-H activation and annulation reaction, the annulation occurs via a 1,2-aryl shift to afford quaternary carbon-centered pyrimidoindolones.
Baruah, Swagata,Saikia, Pallabi,Duarah, Gauri,Gogoi, Sanjib
supporting information
p. 3753 - 3757
(2018/07/25)

Transition-metal-free Chemoselective Oxidative C?C Coupling of the sp3 C?H Bond of Oxindoles with Arenes and Addition to Alkene: Synthesis of 3-Aryl Oxindoles, and Benzofuro- and Indoloindoles
A transition-metal (TM)-free and halogen-free NaOtBu-mediated oxidative cross-coupling between the sp3 C?H bond of oxindoles and sp2 C?H bond of nitroarenes has been developed to access 3-aryl substituted and 3,3-aryldisubstituted oxindoles in DMSO at room temperature in a short time. Interestingly, the sp3 C?H bond of oxindoles could also react with styrene under TM-free conditions for the practical synthesis of quaternary 3,3-disubstituted oxindoles. The synthesized 3-oxindoles have also been further transformed into advanced heterocycles, that is, benzofuroindoles, indoloindoles, and substituted indoles. Mechanistic experiments of the reaction suggests the formation of an anion intermediate from the sp3 C?H bond of oxindole by tert-butoxide base in DMSO. The addition of nitrobenzene to the in-situ generated carbanion leads to the 3-(nitrophenyl)oxindolyl carbanion in DMSO which is subsequently oxidized to 3-(nitro-aryl) oxindole by DMSO.
Sattar, Moh.,Rathore, Vandana,Prasad, Ch. Durga,Kumar, Sangit
supporting information
p. 734 - 743
(2017/04/13)

Pd/Cu-catalyzed dual C-H bond carbonylation towards the synthesis of fluorazones
Pd/Cu catalyzed oxidative dual C-H bond activation/carbonylation still remains a great challenge due to the generation of by-products via C-C bond formation. Herein we developed a straightforward Pd/Cu-catalyzed oxidative dual C-H bond carbonylation process to access biologically and pharmaceutically important fluorazones from easily available N-aryl pyrroles and CO. A wide range of functional groups were well tolerated in this transformation, and O2 could be utilized as the only terminal oxidant to promote the oxidative carbonylation process.
Liao, Fan,Shi, Renyi,Sha, Yuchen,Xia, Jianhui,Liao, Weilin,Lei, Aiwen
supporting information
p. 4354 - 4357
(2017/04/21)

Rh(III)-Catalyzed bilateral cyclization of aldehydes with nitrosos toward unsymmetrical acridines proceeding with C-H functionalization enabled by a transient directing group
A Rh(iii)-catalyzed bilateral cyclization was developed for the efficient construction of acridines proceeding with C-H functionalization whereby in situ formation and removal of an imino transient directing group in the presence of catalytic amount of BnNH2 are achieved. In this transformation, a sequential Rh(iii)-catalyzed C-H amination, cyclization, and aromatization process was involved.
Hu, Weiming,Zheng, Qingheng,Sun, Song,Cheng, Jiang
supporting information
p. 6263 - 6266
(2017/07/07)

Copper-Catalyzed C–N, C–O Coupling Reaction of Arylglyoxylic Acids with Isatins
The copper(II)-catalyzed decarboxylative coupling reactions of arylglyoxylic acids with isatins afford 4H-benzo[d][1,3]oxazin-4-ones via decarbonylation and concurrent C–N, C–O bond formation. (Figure presented.).
Prakash, Rashmi,Gogoi, Sanjib
supporting information
p. 3046 - 3049
(2016/10/09)

The amide C-N bond of isatins as the directing group and the internal oxidant in Ru-catalyzed C-H activation and annulation reactions: Access to 8-amido isocoumarins
The N-O, N-N and O-O bonds are the frequently used internally oxidative directing groups used in various redox-neutral coupling reactions. The sole use of the C-N bond as the oxidizing directing group was reported recently by Li X. and co-workers for the Rh(iii)-catalyzed C-H activation of phenacyl ammonium salts. Herein, we report the use of the amide C-N bond of isatins as the oxidizing directing group for the Ru(ii)-catalyzed redox-neutral C-H activation and annulation reactions with alkynes which afford 8-amido isocoumarins. The reaction also features excellent regioselectivity with alkyl aryl substituted alkynes.
Kaishap, Partha Pratim,Sarma, Bipul,Gogoi, Sanjib
supporting information
p. 9809 - 9812
(2016/08/04)

Generation, Characterization, and Reactivity of a CuII-Alkylperoxide/Anilino Radical Complex: Insight into the O-O Bond Cleavage Mechanism
The reaction of [CuI(TIPT3tren) (CH3CN)]ClO4 (1) and cumene hydroperoxide (C6H5C(CH3)2OOH, ROOH) at -60°C in CH2Cl2 gave a CuII-alkylperoxide/anilino radical complex 2, the formation of which was confirmed by UV-vis, resonance Raman, EPR, and CSI-mass spectroscopy. The mechanism of formation of 2, as well as its reactivity, has been explored.
Paria, Sayantan,Ohta, Takehiro,Morimoto, Yuma,Ogura, Takashi,Sugimoto, Hideki,Fujieda, Nobutaka,Goto, Kei,Asano, Kaori,Suzuki, Takeyuki,Itoh, Shinobu
supporting information
p. 10870 - 10873
(2015/09/15)

Rh-Catalyzed oxidative C-H activation/annulation: Converting anilines to indoles using molecular oxygen as the sole oxidant
A practical and efficient Rh(iii)-catalyzed aerobic C-H activation has been developed for the facile synthesis of a broad range of indoles from simple anilines and alkynes. The protocol could be conducted under mild conditions and used environmentally friendly oxygen as the sole clear oxidant.
Zhang, Guoying,Yu, Hui,Qin, Guiping,Huang, Hanmin
supporting information
p. 4331 - 4334
(2014/04/17)

Regioselective synthesis of indoles via rhodium-catalyzed C-H activation directed by an in-situ generated redox-neutral group
A regioselective synthesis of indoles from arylhydrazine hydrochlorides with alkynes and diethyl ketone catalyzed by a rhodium complex is described. A possible mechanism involving an in-situ generated oxidizing directing group -N-Ni'CR1R2 assisted ortho-C-H activation and reductive elimination are proposed. The catalytic reaction is highly compatible with a wide range of functional arylhydrazines and alkynes. The reaction proceeds under mild reaction conditions and is atom-step economical.
Muralirajan, Krishnamoorthy,Cheng, Chien-Hong
supporting information
p. 1571 - 1576
(2014/06/09)

Metal-free regioselective hydrobromination of alkynes through CH/CBr activation
A metal-free regioselective hydrobromination of alkynes has been developed to provide the Markovnikov-type vinyl bromides in good yields using dibromomethane/N,N-dimethylaniline as in-situ 'HBr' source. This protocol also represents an elegant example of the activation of sp2 CH and CBr bonds in one pot, in which 'HBr' is generated and transferred under mild metal-free conditions. D-incorporated experiments were employed to investigate the reaction mechanism and a plausible reaction path was proposed.
Chen, Xiuling,Chen, Tieqiao,Xiang, Yuqiang,Zhou, Yongbo,Han, Daoqing,Han, Li-Biao,Yin, Shuang-Feng
supporting information
p. 4572 - 4575
(2014/12/10)

Indole synthesis via rhodium catalyzed oxidative coupling of acetanilides and internal alkynes
The oxidative synthesis of highly functionalized indoles from simple anilines and internal alkynes mediated by a rhodium(III) catalyst is described. Good yields are obtained for a variety of aniline substrates, and good regioselectivity is obtained for the more sterically accessible position when meta-substituted anilines are used. Symmetrical and unsymmetrical alkynes react efficiently with high (>40:1) C2/C3 regioselectivity when aryl/alkyl substituted alkynes are used. Copyright
Stuart, David R.,Bertrand-Laperle, Megan,Burgess, Kevin M. N.,Fagnou, Keith
supporting information; experimental part
p. 16474 - 16475
(2009/04/13)

The synthesis of labelled forms of saquinavir
The development of the HIV-protease inhibitor, saquinavir (Ro 31-8959), required a range of analytical methods for the measurement of the parent drug and drug-related material in biological fluids. This paper describes the synthesis of 14-carbon and tritium labelled compounds used for in vivo and in vitro investigations of the absorption and disposition of saquinavir in animals and man. It also discusses the preparation of saquinavir labelled with deuterium and stable isotopes of carbon and nitrogen. These forms of the drug were needed for bioequivalence studies in which HPLC/MS/MS was employed for the measurement of plasma concentrations. Finally, the synthesis of a 125-iodine labelled tracer used in a radioimmunoassay for saquinavir is described.
Wiltshire,Prior,Dhesi,Trach,Schlageter,Schoenenberger
p. 1103 - 1126
(2007/10/03)

Electron Transfer Reactions and Mobile Holes in Radiolysis of Squalane. Time-Resolved FDMR Study
Fluorescence detected magnetic resonance (FDMR) is applied to study ion-molecule reactions in squalane (2,6,10,15,19,23-hexamethyltetracosane).Several time-resolved pulsed FDMR experiments are suggested to measure rate constants of scavenging by aromatic solutes.These constants vary from 5E8 to 1.6E9 mol-1 dm3 s-1.The ion-molecule reactions of radical cations are somewhat slower than reactions of radical anions.The scavenging of the alkane hole is significantly faster than ion-molecule reactions of molecular cations.The mobile hole decays on a time scale of several tens of nanoseconds.These FDMR results are in accord with our recent work on transient absorption spectroscopy in radiolysis of squalane.
Shkrob, I. A.,Trifunac, A. D.
p. 14681 - 14687
(2007/10/03)

Kinetic models for gas-phase electron-transfer reactions between nitrobenzenes
Rate constants for gas-phase electron-transfer reactions between substituted nitrobenzenes have been measured using ion cyclotron resonance spectroscopy. On the basis of the assumption that these reactions occur through the formation of an intermediate complex, a statistical model is used to interpret the reaction kinetics. The intersecting parabolas quantum mechanical model provides an alternative description of the energy surface. Energy barriers are found to be consistent for the two methods. The results for exothermic reactions are consistent with a Marcus theory analysis, but suggest that a zero-order potential energy surface may not be completely adequate for quantitative prediction of reaction rates.
Han, Chau-Chung,Wilbur, James L.,Brauman, John I.
p. 887 - 893
(2007/10/02)

A Linear Free Energy Relationship for an Equilibrium Isotope Effect
The solution electron affinities of a series of monosubstituted phenyl-d5 benzenes relative to their perprotiated analogues were measured via electron paramagnetic resonance studies.The equilibrium constant for the electron transfer X-C6H5.- + X-C6D5 X-C6H5 + X-C6D5.-, where X = H, C6D5, CN, NO2, OCH3, tert-butyl, was found to be less than unity for all cases.However, this equilibrium constant is closer to unity for those systems where the substituent is electron withdrawing in nature, and it deviates further from unity for those systems that have an electron-donating group as the substituent.A linear free energy relationship was found, and the positive ρ value (0.34) is presumably due to the fact that there is a smaller excess charge and spin density from the antibonding electron in the area of the molecule where isotopic substitution takes place, for those systems where the ? value of the substituent is positive.
Stevenson, Gerald R.,Wehrmann, Glenn C.,Reiter, Richard C.
p. 901 - 905
(2007/10/02)

Strong Environmental Effects upon ΔG0 of Electron Transfer between an Anion Radical and Its Perdeuteriated Analogue
The free energy change for electron transfer from the anion radical of nitrobenzene to perdeuteriated nitrobenzene (PhNO2.- + PhNO2-d5 = PhNO2 + PhNO2-d5.-) has been determined via solution-phase EPR measurements and physical separation of the neutral nitrobenzenes from the solid anion-radical salts.This free energy is largest in hexamethyl-phosphoramide (Γ0 = 1400 J/mol) where the anion radical exists free of ion association and hydrogen bonding.In liquid ammonia, where the anion radicals are strongly hydrogen bonded through the NO2 group, this free energy is only 389 J/mol.The addition of extra sodium cations to the ammonia solution results in a further decrease in ΔG0 to 243 J/mol where it is of the same magnitude as in the solid-state anion radical where the interaction between the cation and anion radical is very strong.Ion association and hydrogen bonding pull spin and charge density into the NO2 group and away from the phenyl ring where isotopic substitution takes place, resulting in a smaller equilibrium isotope effect.In HMPA the isotope effect is even larger than in the gas phase due to stronger solvation of the phenyl moiety than of the NO2 group in this solvent.
Stevenson, Gerald R.,Wehrmann, Glenn C.,Reiter, Richard C.
p. 6936 - 6939
(2007/10/02)

RUTHENIUM-CATALYSED REARRANGEMENTS OF AZOBENZENES IV. REARRANGEMENTS OF DEUTERATED AZOBENZENES TO 1-PHENYLBENZIMIDAZOLE AND N-PHENYL-1,2-PHENYLENEDIAMINE DERIVATIVES
The ruthenium-catalysed reactions of azobenzene-d10 and 4,4'-disubstituted azobenzene-d8 compounds with non-deuterated tri-n-butylamine, n-butanol or 2-propanol give 1-phenylbenzimidazole or N-phenyl-1,2-phenylenediamine derivatives.The distibution of 1H in the aromatic rings of these products and in the recovered azobenzenes indicated that in all cases ortho-metallation of the azobenzene derivative has occured.The significance of those and other observations for the mechanism of these reactions is discussed.
Spencer, Alwyn
p. 199 - 210
(2007/10/02)

Sytheses and ENDOR Studies of Selectively Deuterated Galvinoxyl Radicals. Complete Determination of the 13C Hyperfine Coupling Constants of Coppingers's Radical
The synthesis of selectively deuterated galvinols is described.Oxidation results in the formation of the respective galvinoxyl free radicals, e.g., Coppinger's radical and Yang's biradical.It is shown that 13C ENDOR signals can be detected for the doublet radicals without 13C labelling, i.e., in natural abundance.The complete set of 13C hyperfine coupling constants of Coppinger's radical could be determined.The ENDOR study of selectively deuterated Yang's biradical in a glassy matrix allowed an unambiguous assignment of the signals to molecular positions, and conclusions with respect to the symmetry of the radical and the hindered rotation of the tert-butyl groups could be drawn.Randomly oriented bisgalvinoxyl biradicals in the triplet spin state give rise to sharp ENDOR lines at the free nuclear Zeeman frequencies due to NMR transitions in the MS=0 electron spin manifold, and it is demonstrated that the respective 2H ENDOR lines show quadrupole splittings.
Kirste, Burkhard,Kurrek, Harry,Sordo, Magdalena
p. 1782 - 1797
(2007/10/02)