1207-92-7Relevant academic research and scientific papers
Palladium-catalyzed amination of aryl bromides and aryl triflates using diphosphane ligands: A kinetic study
Guari, Yannick,Van Strijdonck, Gino P. F.,Boele, Maarten D. K.,Reek, Joost N. H.,Kamer, Paul C. J.,Van Leeuwen, Piet W. N. M.
, p. 475 - 482 (2001)
[Pd(P-O-P)(Ar)]+ complexes with ligands that have wide bite angles are active catalysts for the coupling of aniline derivatives with aryl triflates. Kinetic studies show that for these systems a fast equilibrium that involves coordination of the amine precedes the deprotonation, which is the rate-limiting step of the reaction. This reaction is faster for compounds with a smaller P-Pd-P angle. When halide salts are present, the base sodium tert-butoxide is activated and adds to the palladium complex. This rate-limiting step is preceded by a fast equilibrium that involves decoordination of the halide. The initial reaction rate is faster for compounds with a larger P-Pd-P angle. This is due to the closer proximity of the oxygen to the Pd center, and this assists in the dissociation of the halide.
Antioxidant activities of phenothiazines and related compounds: Correlation between the antioxidant activities and dissociation energies of O-H or N-H bonds
Yamamura, Tatsuo,Suzuki, Kyouichi,Yamaguchi, Tatsuya,Nishiyama, Tomihiro
, p. 413 - 419 (1997)
The antioxidant activities of phenothiazines, carbazoles, and related diphenylamines were evaluated in the oxidation of tetralin at 60°C and linoleic acid micelles in aqueous dispersion at 37°C induced by an azo initiator. Phenothiazines were highly antioxidant in both systems. Although diphenylamine and carbazole were not good antioxidants, those having a hydroxy group as a substituent at the ortho or para position to the amino group were potently antioxidant. The antioxidant activity of o-hydroxydiphenylamine was much greater than that of other compounds in both systems due to a stabilization of the phenoxyl radical by delocalization of the unpaired electron to the p-type lone pair of the amino group. A semiempirical MNDO-AM1 calculation was applied to study hydrogen abstractions of antioxidants in the chain process of autoxidation. These results indicated that the rates of oxidation during the induction period correlated with the dissociation energies of the O-H or N-H bonds.
Pd-catalyzed amination in a polar medium: Rate enhancement, convenient product isolation, and tandem Suzuki cross-coupling
Stauffer, Shaun R.,Steinbeiser, Melissa A.
, p. 2571 - 2575 (2005)
A catalytic system utilizing a polar medium for the Pd-catalyzed amination reaction is described. This system utilizes Pd[P(t-Bu)3]2 and a weak base and displays a modest rate enhancement compared to similar existing protocols. Significant functional group tolerance is observed in both amine and aryl halide, including carboxylates, carbamates, nitriles, amides, and esters. Product isolation after filtration and automated reverse-phase chromatography readily permits parallel synthetic approaches if desired.
Circularly polarized luminescence from bridged triarylamine helicenes
Field, Jason E.,Muller, Gilles,Riehl, James P.,Venkataraman
, p. 11808 - 11809 (2003)
The first examples of circularly polarized luminescence from chiral bridged triarylamine-based heterohelicene molecules are reported. The luminescence dissymmetry factors are ～ |0.001|. Copyright
The synthesis of a [2.2]paracyclophane-derived secondary phosphine oxide and a study of its reactivity
Mungalpara, Maulik N.,Wang, Jingjing,Coles, Martyn P.,Plieger, Paul G.,Rowlands, Gareth J.
, p. 5519 - 5527 (2018)
A planar chiral secondary phosphine oxide based on [2.2]paracyclophane was synthesized and its chemistry investigated; it was shown to be a competent pre-ligand in palladium(0)-mediated reactions, and displayed promising activity in gold(I)-catalysed cyclisations. The secondary phosphine oxide could be transformed into a collection of P-stereogenic tertiary phosphine oxides. These are rare examples of the planar chirality of [2.2]paracyclophane being combined with a P-stereogenic centre. Unfortunately, epimerisation of the phosphorus stereocentre during reduction limits the use of this chemistry.
Solvent free amination reactions of aryl bromides at room temperature catalyzed by a (π-allyl)palladium complex bearing a diphosphinidenecyclobutene ligand
Gajare, Anil S.,Toyota, Kozo,Yoshifuji, Masaaki,Ozawa, Fumiyuki
, p. 6504 - 6506 (2004)
An air- and moisture-stable (π-allyl)palladium complex bearing a unique diphosphinidenecyclobutene ligand effectively catalyzes amination reactions of aryl bromides with amines, where the reactions proceed under mild conditions without solvent, with 2 mol % of catalyst and 1 equiv of t-BuOK at room temperature. Under these conditions the amination products were obtained in good to excellent isolated yields.
Antioxidant effects of the hydroxy groups in the simple phenolic carbazoles
Hieda, Yuhzo,Hatae, Noriyuki,Anraku, Makoto,Matsuura, Nobuyasu,Uemura, Kazuhide,Hibino, Satoshi,Choshi, Tominari,Tomida, Hisao,Hori, Osamu,Fujioka, Haruto
, p. 120 - 132 (2016)
Antioxidant activities of the simple phenolic carbazoles 5-11 were evaluated by 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate)+ radical scavenging assays. The simple phenolic carbazoles 5-7, 9, and 11 exhibited stronger antioxidant activities than α-tocopherol, and similar antioxidant activities as phenolic carbazole alkaloids carazostatin (1), and carbazomadurins A (3) and B (4). Bond dissociation energies and highest occupied molecule orbital energy levels of a series of phenolic carbazoles including phenolic carbazole alkaloids were calculated. The reducing ability of the phenolic carbazole core could be important role for the antioxidant activity of carbazole alkaloids 1, 3, and 4.
Diastereoselective Allylation of Aldehydes by Dual Photoredox and Chromium Catalysis
Schwarz, J. Luca,Sch?fers, Felix,Tlahuext-Aca, Adrian,Lückemeier, Lukas,Glorius, Frank
, p. 12705 - 12709 (2018)
Herein, we report the redox-neutral allylation of aldehydes with readily available electron-rich allyl (hetero-) arenes, β-alkyl styrenes and allyl-diarylamines. This process was enabled by the combination of photoredox and chromium catalysis, which allowed a range of homoallylic alcohols to be prepared with high levels of selectivity for the anti diastereomer. Mechanistic investigations support the formation of an allyl chromium intermediate from allylic C(sp3)-H bonds and thus significantly extends the scope of the venerable Nozaki-Hiyama-Kishi reaction.
N-Heterocyclic Carbene Palladium(II) Amine Complexes: The Role of Primary Aryl- or Alkylamine Binding and Applications in the Buchwald-Hartwig Amination Reaction
Hsu, Yu-Cheng,Chen, Ming-Tsz
supporting information, (2021/12/24)
N-heterocyclic carbene-palladium(II) amine complexes bearing primary aryl- or alkylamines were synthesized. The prepared complexes were characterized by single crystal X-ray diffraction as well as NMR spectroscopy. These complexes exhibited good catalytic activities for the Buchwald-Hartwig amination reaction of aryl chlorides to afford arylated anilines under mild conditions. All reactions were carried out in air and all starting materials were used as supplied without purification. 21 expected coupling products were obtained in moderate to high yields under optimum conditions.
Copper nanoparticle anchored biguanidine-modified Zr-UiO-66 MOFs: a competent heterogeneous and reusable nanocatalyst in Buchwald-Hartwig and Ullmann type coupling reactions
Veisi, Hojat,Neyestani, Narges,Pirhayati, Mozhgan,Ahany Kamangar, Sheida,Lotfi, Shahram,Tamoradi, Taiebeh,Karmakar, Bikash
, p. 22278 - 22286 (2021/07/02)
We have designed a functionalized metal-organic framework (MOF) of UiO topology as a support, with an extremely high surface area, adjustable pore sizes and stable crystalline coordination polymeric structure and implanted copper (Cu) nanoparticles thereon. The core three dimensional Zr-derived MOF (UiO-66-NH2) was modified with a biguanidine moiety following a covalent post-functionalization approach. The morphological and physicochemical features of the material were determined using analytical methods such as FT-IR, SEM, TEM, EDX, atomic mapping, XRD and ICP-OES. The SEM and XRD results justified the unaffected morphology of Zr-MOF after structural modifications. The as-synthesized UiO-66-biguanidine/Cu nanocomposite was catalytically explored in the aryl and heteroaryl Buchwald-Hartwig C-N and Ullmann type C-O cross coupling reactions with excellent yields. A library of biaryl amine and biaryl ethers was synthesized over the catalyst under mild and green conditions. Furthermore, the catalyst was isolated by centrifugation and recycled 11 times with no significant copper leaching or change in its activity.
