1058-14-6Relevant academic research and scientific papers
An open-shell spin singlet copper-nitrene intermediate binding redoxinnocent metal ions: Influence of the Lewis acidity of the metal ions on spectroscopic and reactivity properties
Monte-Prez, Ins,Kundu, Subrata,Ray, Kallol
, p. 78 - 82 (2015)
The yield of the Lewis acid adducts of a copper-tosylnitrene intermediate and their decay are dependent on the Lewis acidity of the redox innocent metal ions. Surprisingly, however, their spectroscopic properties and reactivity in nitrene transfer reaction with PPh3 are independent of the nature of the Lewis acid used. The result provides some new insights into the structure and reactivity of the Lewis-acid bound copper nitrene complexes.
A Dicopper Nitrenoid by Oxidation of a CuICuICore: Synthesis, Electronic Structure, and Reactivity
Desnoyer, Addison N.,Nicolay, Amélie,Ziegler, Micah S.,Lakshmi,Cundari, Thomas R.,Tilley, T. Don
, p. 7135 - 7143 (2021)
A dicopper nitrenoid complex was prepared by formal oxidative addition of the nitrenoid fragment to a dicopper(I) center by reaction with the iminoiodinane PhINTs (Ts = tosylate). This nitrenoid complex, (DPFN)Cu2(μ-NTs)[NTf2]2 (DPFN = 2,7-bis(fluorodi(2-pyridyl)methyl)-1,8-naphthyridine), is a powerful H atom abstractor that reacts with a range of strong C-H bonds to form a mixed-valence Cu(I)/Cu(II) μ-NHTs amido complex in the first example of a clean H atom transfer to a dicopper nitrenoid core. In line with this reactivity, DFT calculations reveal that the nitrenoid is best described as an iminyl (NR radical anion) complex. The nitrenoid was trapped by the addition of water to form a mixed-donor hydroxo/amido dicopper(II) complex, which was independently obtained by reaction of a Cu2(μ-OH)2 complex with an amine through a protonolysis pathway. This mixed-donor complex is an analogue for the proposed intermediate in copper-catalyzed Chan-Evans-Lam coupling, which proceeds via C-X (X = N or O) bond formation. Treatment of the dicopper(II) mixed donor complex with MgPh2(THF)2 resulted in generation of a mixture that includes both phenol and a previously reported dicopper(I) bridging phenyl complex, illustrating that both reduction of dicopper(II) to dicopper(I) and concomitant C-X bond formation are feasible.
Construction of benzo-1,2,3-thiazaphosphole heterocycles by annulations of ortho-phosphinoarenesulfonyl fluorides with trimethylsilyl azide
Luo, Wenjun,Wang, Zhenguo,Cao, Xiaohui,Liang, Dacheng,Wei, Mingjie,Yin, Keshu,Li, Le
, p. 14785 - 14794 (2020)
Annulations of ortho-phosphinoarenesulfonyl fluorides with trimethylsilyl azide were developed to access an unprecedented benzo-1,2,3-thiazaphosphole heterocycle. A corresponding reaction mechanism was proposed and further elucidated by experimental and computational studies. The reaction proceeds through a Staudinger-type iminophosphorane intermediate followed by intramolecular trapping with sulfonyl fluoride.
Palladium-Catalyzed Stereoselective Hydrodefluorination of Tetrasubstituted gem-Difluoroalkenes
Ma, Qiao,Liu, Caroline,Tsui, Gavin Chit
supporting information, p. 5193 - 5197 (2020/07/04)
A highly stereoselective palladium(0)-catalyzed hydrodefluorination (HDF) of tetrasubstituted gem-difluoroalkenes is developed. By using catalytic Pd(PPh3)4 (2.5-5 mol percent) and hydrosilane Me2PhSiH, various trisubstituted terminal (E)-monofluoroalkenes can be synthesized with excellent E/Z selectivity (>99:1) and good functional group tolerability. The key stereocontrol should be exerted by an ester-directed C-F bond oxidative addition step in the catalytic cycle.
Sulfonylimino group transfer reaction using imino-λ3-iodanes with I2 as catalyst under metal-free conditions
Yoshimura, Akira,Makitalo, Cody L.,Jarvi, Melissa E.,Shea, Michael T.,Postnikov, Pavel S.,Rohde, Gregory T.,Zhdankin, Viktor V.,Saito, Akio,Yusubov, Mekhman S.
, (2019/03/19)
A new practical procedure of imination for sulfide has been developed. The treatment of (N-tosylimino)-phenyl-λ3-iodane, PhINTs, with various sulfides in the presence of a catalytic amount of I2 under metal-free conditions affords the corresponding N-tosylsulfilimine compounds with moderate to good yields. This facile transfer procedure of the sulfonylimino group can also be applied to triphenylphosphine to produce the respective iminotriphenylphosphoranes in high yields. According to the reaction mechanism studies, the process of imination from (N-tosylimino)-phenyl-λ3-iodane to sulfide under the conditions may involve radical steps within the reaction mechanism.
Designed To React: Terminal Copper Nitrenes and Their Application in Catalytic C?H Aminations
Moegling, Julian,Hoffmann, Alexander,Thomas, Fabian,Orth, Nicole,Liebh?user, Patricia,Herber, Ulrich,Rampmaier, Robert,Stanek, Julia,Fink, Gerhard,Ivanovi?-Burmazovi?, Ivana,Herres-Pawlis, Sonja
supporting information, p. 9154 - 9159 (2018/07/25)
Heteroscorpionate ligands of the bis(pyrazolyl)methane family have been applied in the stabilisation of terminal copper tosyl nitrenes. These species are highly active intermediates in the copper-catalysed direct C?H amination and nitrene transfer. Novel perfluoroalkyl-pyrazolyl- and pyridinyl-containing ligands were synthesized to coordinate to a reactive copper nitrene centre. Four distinct copper tosyl nitrenes were prepared at low temperatures by the reaction with SO2tBuPhINTs and copper(I) acetonitrile complexes. Their stoichiometric reactivity has been elucidated regarding the imination of phosphines and the aziridination of styrenes. The formation and thermal decay of the copper nitrenes were investigated by UV/Vis spectroscopy of the highly coloured species. Additionally, the compounds were studied by cryo-UHR-ESI mass spectrometry and DFT calculations. In addition, a mild catalytic procedure has been developed where the copper nitrene precursors enable the C?H amination of cyclohexane and toluene and the aziridination of styrenes.
A cobalt(ii) iminoiodane complex and its scandium adduct: Mechanistic promiscuity in hydrogen atom abstraction reactions
Kundu, Subrata,Chernev, Petko,Engelmann, Xenia,Chung, Chan Siu,Dau, Holger,Bill, Eckhard,England, Jason,Nam, Wonwoo,Ray, Kallol
supporting information, p. 14538 - 14543 (2016/09/28)
In addition to oxometal [Mn+O] and imidometal [Mn+NR] units, transient metal-iodosylarene [M(n-2)+-OIPh] and metal-iminoiodane [M(n-2)+-N(R)IPh] adducts are often invoked as a possible second oxidant responsible for the oxo and imido group transfer reactivity. Although a few metal-iodosylarene adducts have been recently isolated and/or spectroscopically characterized, metal-iminoiodane adducts have remained elusive. Herein, we provide UV-Vis, EPR, NMR, XAS and DFT evidence supporting the formation of a metal-iminoiodane complex 2 and its scandium adduct 2-Sc. 2 and 2-Sc are reactive toward substrates in the hydrogen-atom and nitrene transfer reactions, which confirm their potential as active oxidants in metal-catalyzed oxidative transformations. Oxidation of para-substituted 2,6-di-tert-butylphenols by 2 and 2-Sc can occur by both coupled and uncoupled proton and electron transfer mechanisms; the exact mechanism depends on the nature of the para substituent.
Zinc chloride catalyzed ring opening of N-arylsulfonyl aziridines by thioamides: A new approach to the synthesis of amidines
Hajibabaei, Khadijeh,Zali-Boeini, Hassan
supporting information, p. 2044 - 2048 (2014/11/08)
The first zinc chloride catalyzed ring opening of N-arylsulfonyl aziridines by thioamides is described. Various thioamides were reacted with N-arylsulfonyl aziridines in the presence of a catalytic amount of dry zinc chloride to provide the corresponding
Chemoselectivity in coupling of azides with thioacids in solution-phase and solvent-free conditions
Nagarajan, Sangaraiah,Shanmugavelan, Poovan,Sathishkumar, Murugan,Priyadharshini, Namachivayam,Sudakar, Padmanaban,Ponnuswamy, Alagusundaram
, p. 668 - 680 (2013/01/15)
Solvent-free rapid coupling of monothiocarboxylic acid with azide affords carboxamide chemoselectively. Triphenyl phosphine included as an additive influences the chemoselectivity, yielding carboxamide and thioamide. Similar variation in the chemoselectivity is observed in the absence and presence of triphenyl phosphine in solution-phase methodology. Rapidity and ecofriendliness of the solvent-free approach to yield the products in just 15min is noteworthy compared to the solution-phase protocol, which has a long reaction time (1-3 days).
O-alkoxyphenyliminoiodanes: Highly efficient reagents for the catalytic aziridination of alkenes and the metal-free amination of organic substrates
Yoshimura, Akira,Nemykin, Victor N.,Zhdankin, Viktor V.
supporting information; experimental part, p. 10538 - 10541 (2011/11/12)
Efficient nitrene precursors: Highly reactive iminoiodane-based nitrene precursors were prepared from ortho-alkoxyiodobenzenes. Owing to the presence of the ortho-substituent on the phenyl ring, these new iminoiodanes have excellent solubility in organic
