1207-92-7Relevant articles and documents
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.
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.
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.
Yoshida,Fueno
, p. 731 (1976)
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.
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.
A quinoxaline-based porous organic polymer containing copper nanoparticles CuNPs@Q-POP as a robust nanocatalyst toward C-N coupling reaction
Gorginpour, Forough,Zali-Boeini, Hassan,Rudbari, Hadi Amiri
, p. 3655 - 3665 (2021/02/03)
A novel porous organic polymer (denoted by Q-POP) was successfully fabricated by free-radical copolymerization of allyl-substituted 2,3-di(2-hydroxyphenyl)1,2-dihydroquinoxaline, and divinylbenzene under solvothermal conditions and used as a new platform for immobilization of copper nanoparticles. The CuNPs@Q-POP nanocatalyst was prepared via incorporating of Cu(NO3)2 into the polymeric network, followed by the reduction of Cu2+ ion with hydrazine hydrate. The obtained materials were characterized through FT-IR, XRD, N2 adsorption-desorption isotherms, ICP, TGA, SEM, HR-TEM, EDX, and the single-crystal X-ray crystallography. The results displayed that Q-POP and CuNPs@Q-POP possessed high surface area, hierarchical porosity, and excellent thermal and chemical stability. The as-synthesized catalyst was utilized for the Ullmann C-N coupling reaction of aromatic amines and different aryl halides to prepare various diarylamine derivatives. All types of aryl halides (except aryl fluorides) were screened in the Ullmann C-N coupling reaction with aromatic amines to produce diaryl amines in good to excellent yields (50-98%), and it turned out that aryl iodides have the best results. Besides, due to the strong interactions between CuNPs, N, and O-atoms of quinoxaline moiety existing in the polymeric framework, the copper leaching from the support was not observed. Furthermore, the catalyst was recycled and reused for five consecutive runs without significant activity loss.
