10282-31-2Relevant articles and documents
An improved method for the palladium-catalyzed amination of aryl triflates
Ahman, Jens,Buchwald, Stephen L.
, p. 6363 - 6366 (1997)
Aryl triflates are coupled with amines using catalytic amounts of Pd(OAc)2 and BINAP and Cs2CO3 as a stoichiometric base. This protocol allows for the efficient amination of electron-poor as well as electron-rich aryl triflates and the reaction conditions are compatible with a wide variety of functional groups.
Influence of biaryl phosphine structure on C-N and C-C bond formation
Pratap, Ramendra,Parrish, Damon,Gunda, Padmaja,Venkataraman,Lakshman, Mahesh K.
, p. 12240 - 12249 (2009)
In order to understand how electronic and other structural characteristics of biphenyl phosphine ligands affect Pd-catalyzed C-N and C-C bond-forming reactions, a new ligand, 2-(dicyclohexylphosphino)-4′-(N,N-dimethylamino)- 1,1′-biphenyl, was synthesized. This compound is isomeric with the commercially available 2-(dicyclohexylphosphino)-2′-(N,N-dimethylamino)-1, 1′-biphenyl that has been useful in C-N bondforming reactions of nucleosides. The new p-dimethylamino biphenyl ligand bears electronic similarities to the o-dimethylamino isomer, but it also possesses structural similarities to 2-(dicyclohexylphosphino)biphenyl, such as the unsubstituted ortho positions in the non-phosphine ring. Whereas 2-(dicyclohexylphosphino)- biphenyl can support catalysts for C-C bond formation, it was not effective in promoting aryl amination of a nucleoside substrate. However, the new ligand proved to be effective in promoting both aryl amination and C-C bond-forming reactions of nucleoside substrates, with some reactions even occurring at room temperature. Thus, the composite structural elements of this new ligand are thought to be criteria for reactivity of the catalytic system derived from it. We have probed the structures of the isomeric N,N-dimethylamino biphenyl ligands by X-ray crystallographic analysis. Interactions of the two ligands with Pd(OAc)2 have been investigated by 31P NMR, and they show substantial stoichiometry-dependent differences. These results have been compared to the interactions of Pd(OAc)2 with 2- (dicyclohexylphosphino)biphenyl as well as 2-(di-tert-butylphosphino)biphenyl, and they reveal marked differences as well. In this process, three cyclopalladated biaryl derivatives have been isolated and characterized by X-ray analysis.
Palladium(II) anchored on polydopamine coated-magnetic nanoparticles (Fe3O4&at;PDA&at;Pd(II)): A heterogeneous and core–shell nanocatalyst in Buchwald–Hartwig C–N cross coupling reactions
Hemmati, Saba,Sarachegol, Pegah,Veisi, Hojat
, p. 64 - 71 (2018)
An efficient method was proposed to synthesize polydopamine (PDA)-coated Fe3O4 nanoparticles (Fe3O4&at;PDA). For the first time, effective deposition of Pd complex is explained by using Fe3O4&at;PDA as a core–shell magnetic coordinator and stabilizer agent. In this method, palladium ions were adsorbed on Fe3O4&at;PDA surfaces through immersion of the Fe3O4&at;PDA into a palladium plating bath. The structure, morphology and physicochemical features of the prepared particles were studied using various analytical methods including high resolution transmission electron microscopy (HR-TEM), field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDS), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma (ICP), thermogravimetric analysis (TGA) and FT-IR spectroscopy. Core–shell Fe3O4&at;PDA/Pd(II) nanoparticles showed excellent catalytic performance as a reusable nanocatalyst in Pd-catalyzed Buchwald–Hartwig C–N cross coupling reaction. A variety of aryl amines were prepared through reaction of aryl halides (chloride, bromide and iodide) and amines in high yields. The catalyst can be recycled and reapplied up to six cycles with no considerable change in its catalytic activity.
Green tea extract–modified silica gel decorated with palladium nanoparticles as a heterogeneous and recyclable nanocatalyst for Buchwald-Hartwig C–N cross-coupling reactions
Veisi, Hojat,Tamoradi, Taiebeh,Karmakar, Bikash,Hemmati, Saba
, (2020)
A novel green tea extract–encapsulated silica gel decorated with in situ–generated Pd nanoparticles is reported as an efficient, green heterogeneous catalyst in the Buchwald-Hartwig C–N cross-coupling reaction. It was characterized by several analytical techniques. Thereafter, a wide range of aryl amines were synthesized in good to excellent yields by reaction of different substituted aryl halides and secondary amines over the catalyst. The material is sufficiently stable and could be used at least six times in a model Buchwald-Hartwig reaction without noticeable change in its catalytic activity. Heterogeneity of the catalyst was examined by a hot filtration test.
Copper-catalyzed electrophilic amination of functionalized diarylzinc reagents
Berman, Ashley M.,Johnson, Jeffrey S.
, p. 364 - 366 (2005)
(Chemical Equation Presented). The copper-catalyzed electrophilic amination of functionalized diarylzinc reagents with O-acyl hydroxylamines allows for the preparation of functionalized tertiary arylamines in high yields, and is noteworthy for the mild re
A highly active catalyst for the room-temperature amination and Suzuki coupling of aryl chlorides
Wolfe, John P.,Buchwald, Stephen L.
, p. 2413 - 2416 (1999)
A unique combination of steric and electronic properties appears to determine the effectiveness of phosphanyl-substituted biphenyls as ligands in palladium-catalyzed aminations and Suzuki coupling of aryl chlorides at room temperature [Eq. (1)]. The oxidative addition step is greatly accelerated, and transmetalation (or Pd-N bond formation) and reductive elimination processes are facilitated. Use of these ligands allows for Suzuki coupling at very low catalyst loadings (as little as 10-6 mol % Pd). R'' = cyclohexyl, tert-butyl.
Ligand-free C-C and C-N cross-couplings with Pd/Nf-G nanocomposite
Shelkar, Radheshyam S.,Shendage, Suresh S.,Nagarkar, Jayashree M.
, p. 4463 - 4467 (2015)
Abstract The catalytic activity of electrochemical deposited Pd nanoparticles on nafion-graphene support was examined for Buchwald-Hartwig amination reaction and Heck coupling reaction. The developed protocol is very efficient and ecofriendly, providing excellent product yield. The Pd/Nf-G catalyst can be used up to four cycles with slight decrease in catalytic activity.
High pressure organic chemistry; XII. A convenient synthesis of aromatic amines from activated aromatic fluorides
Kotsuki,Kobayashi,Matsumoto,Suenaga,Nishizawa
, p. 1147 - 1148 (1990)
Aromatic fluorides containing electron-withdrawing substituents are cleanly reacted with amines at 10 kbar pressure to give various aromatic amines.
Efficient palladium catalysts for the amination of aryl chlorides: A comparative study on the use of phosphium salts as precursors to bulky, electron-rich phosphines
Tewari, Amit,Hein, Martin,Zapf, Alexander,Beller, Matthias
, p. 9705 - 9709 (2005)
Alkyl-di-(1-adamantyl)phosphonium salts are practical ligand precursors for the palladium-catalyzed amination of aryl chlorides. In the presence of typically 0.5 mol% Pd(OAc)2 and 1 mol% of ligand precursor a variety of activated and deactivated aryl chlorides can be aminated in good to excellent yield (73-99%). Applying optimized conditions catalyst turnover numbers up to 10,000 have been achieved.
An air-stable palladium/N-heterocyclic carbene complex and its reactivity in aryl amination
Viciu, Mihai S.,Kissling, Rebecca M.,Stevens, Edwin D.,Nolan, Steven P.
, p. 2229 - 2231 (2002)
(matrix presented) The synthesis and characterization of [Pd(IPr)Cl2]2 (1), an air- and moisture-stable complex, is reported. The utilization of 1 as a catalyst for amination of aryl chlorides and bromides with a variety of amine coupling partners under mild conditions is described. The amination reactions with 1 show a remarkable insensitivity to oxygen and water, and thus the amination reactions could be performed in air on the benchtop with undried reagent grade solvents and substrates with small effects on reaction times and conversions.
High yields of meta-substituted amination products in the S(N)Ar substitution of benzenes
Brown,Foubister,Ratcliffe
, p. 1219 - 1222 (1999)
Morpholine substitution in fluorobenzenes containing a meta-substituted electron withdrawing group proceeds in DMSO at 100 °C over 60 h to give meta-substitution products (by fluoride ion displacement) in pure isolated yields of 19-98%.
On the nature of the 'heterogeneous' catalyst: Nickel-on-charcoal
Lipshutz, Bruce H.,Tasler, Stefan,Chrisman, Will,Spliethoff, Bernd,Tesche, Bernd
, p. 1177 - 1189 (2003)
Results from aromatic aminations and Kumada couplings, together with spectroscopic analyses (TEM, EDX, ICP-AES, React-IR), reveal that catalysis using nickel-on-charcoal (Ni/C) is most likely of a homogeneous rather than heterogeneous nature. In the course of a reaction with Ni/C, nickel bleed from the support was calculated to be as high as 78%. However, the existence of an equilibrium for this homogeneous species between nickel located inside vs outside the pore system of charcoal strongly favors the former, thus leaving only traces of metal detectable in solution. This accounts for virtually complete recovery of nickel on the charcoal following filtration of a reaction mixture and allows for recycling of the catalyst. TEM and EDX data were used to explain different reactivity profiles of Ni/C, which depended upon the method of reduction used to convert Ni(II)/C to Ni(0) as well as the level of nickel loading on the support.
Application of a New Bicyclic Triaminophosphine Ligand in Pd-Catalyzed Buchwald-Hartwig Amination Reactions of Aryl Chlorides, Bromides, and Iodides
Urgaonkar, Sameer,Xu, Ju-Hua,Verkade, John G.
, p. 8416 - 8423 (2003)
The new bicyclic triaminophosphine ligand P(i-BuNCH2) 3CMe (3) has been synthesized in three steps from commercially available materials and its efficacy in palladium-catalyzed reactions of aryl halides with an array of amines has been demonstrated. Electron-poor, electron-neutral, and electron-rich aryl bromides, chlorides, and iodides participated in the process. The reactions encompassed aromatic amines (primary or secondary) and secondary amines (cyclic or acyclic). It has also been shown that the weak base Cs2CO3 can be employed with ligand 3, allowing a variety of functionalized substrates (e.g., those containing esters and nitro groups) to be utilized in our amination protocols. This ligand provides a remarkably general, efficient, and mild palladium catalyst for aryl iodide amination. Although 3 is slightly air and moisture sensitive, easy procedures can be adopted that avoid the need of a glovebox. Comparisons of the efficacy of 3 in these reactions with that of the proazaphosphatrane P(i-BuNCH2CH2)3N (2) reveal that in addition to the opportunity for transannulation in 2 (but not in 3), other significant stereoelectronic contrasts exist between these two ligands which help account for differences in the activities of the Pd/2 and Pd/3 catalytic systems.
Palladium-catalyzed amination of aryl bromides using temperature-controlled microwave heating
Wan, Yiqian,Alterman, Mathias,Hallberg, Anders
, p. 1597 - 1600 (2002)
Fast Palladium-catalyzed aminations of aryl bromides have been conducted in a non-inert reaction medium with temperature-controlled microwave heating. With a reaction time of 4 minutes at 130°C or 180°C, both electron-rich and electron-deficient aryl bromides reacted with various amines to provide fair to good yields of the corresponding secondary and tertiary anilines. As an example the amination of 4-bromobenzonitrile with imidazole is presented.
Palladium-Catalyzed Amination of Aryl Triflates
Wolfe, John P.,Buchwald, Stephen L.
, p. 1264 - 1267 (1997)
The conversion of aryl triflates to the corresponding aniline derivatives was accomplished in moderate to good yield using a catalyst consisting of the combination of palladium acetate (2 mol %) and either BINAP or Tol-BINAP. In contrast to the corresponding palladium-catalyzed amination of aryl bromides and iodides, electronically neutral aryl triflates gave higher yields of arylamines than did electron deficient aryl triflates, presumably due to the increased rate of base-promoted triflate cleavage in electron deficient substrates.
Rapid and convenient synthesis of N-arylmorpholines under microwave irradiation
Li, Hong Bo,Liang, Wu,Ma, Chang Peng,Kai, Yong Mao,Li, Lei,Zhang, Yong Gang
, p. 995 - 998 (2013)
A series of N-arylmorpholines 1a-1n was obtained by cyclocondensation of arylamines and diethylene glycol dimesylate under microwave irradiation in an aqueous potassium carbonate medium. The reaction is rapid and convenient, and a variety of functional groups are tolerated in the process.
A highly active catalyst for palladium-catalyzed cross-coupling reactions: Room-temperature suzuki couplings and animation of unactivated aryl chlorides [22]
Old,Wolfe,Buchwald
, p. 9722 - 9723 (1998)
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Development of second generation gold-supported palladium material with low-leaching and recyclable characteristics in aromatic amination
Al-Amin, Mohammad,Arai, Satoshi,Hoshiya, Naoyoki,Honma, Tetsuo,Tamenori, Yusuke,Sato, Takatoshi,Yokoyama, Mami,Ishii, Akira,Takeuchi, Masashi,Maruko, Tomohiro,Shuto, Satoshi,Arisawa, Mitsuhiro
, p. 7575 - 7581 (2013)
An improved process for the preparation of sulfur-modified gold-supported palladium material [SAPd, second generation] is presented. The developed preparation method is safer and generates less heat (aqueous Na 2S2O8 and H2SO4) for sulfur fixation on a gold surface, and it is superior to the previous method of preparing SAPd (first generation), which requires the use of the more heat-generating and dangerous piranha solution (concentrated H 2SO4 and 35% H2O2) in the sulfur fixation step. This safer and improved preparation method is particularly important for the mass production of SAPd (second generation) for which the catalytic activity was examined in ligand-free Buchwald-Hartwig cross-coupling reactions. The catalytic activities were the same between the first and second generation SAPds in aromatic aminations, but the lower palladium leaching properties and safer preparative method of second generation SAPd are a significant improvement over the first generation SAPd.
Nickel-catalyzed electrophilic amination of organozinc halides
Berman, Ashley M.,Johnson, Jeffrey S.
, p. 1799 - 1801 (2005)
The nickel-catalyzed electrophilic amination of organozinc halides with O-benzoyl N,N-dialkyl hydroxylamines allows for the preparation of a variety of aryl and alkyl tertiary amines in good yield. The reaction is noteworthy for the mild reaction conditions employed (room temperature) and the ease of product purification (acid/base extractive work up). Georg Thieme Verlag Stuttgart.
A “universal” catalyst for aerobic oxidations to synthesize (hetero)aromatic aldehydes, ketones, esters, acids, nitriles, and amides
Bartling, Stephan,Beller, Matthias,Chandrashekhar, Vishwas G.,Jagadeesh, Rajenahally V.,Rabeah, Jabor,Rockstroh, Nils,Senthamarai, Thirusangumurugan
supporting information, p. 508 - 531 (2022/02/11)
Functionalized (hetero)aromatic compounds are indispensable chemicals widely used in basic and applied sciences. Among these, especially aromatic aldehydes, ketones, carboxylic acids, esters, nitriles, and amides represent valuable fine and bulk chemicals, which are used in chemical, pharmaceutical, agrochemical, and material industries. For their synthesis, catalytic aerobic oxidation of alcohols constitutes a green, sustainable, and cost-effective process, which should ideally make use of active and selective 3D metals. Here, we report the preparation of graphitic layers encapsulated in Co-nanoparticles by pyrolysis of cobalt-piperazine-tartaric acid complex on carbon as a most general oxidation catalyst. This unique material allows for the synthesis of simple, functionalized, and structurally diverse (hetero)aromatic aldehydes, ketones, carboxylic acids, esters, nitriles, and amides from alcohols in excellent yields in the presence of air.
Product selective reaction controlled by the combination of palladium nanoparticles, continuous microwave irradiation, and a co-existing solid; ligand-free Buchwald-Hartwig aminationvs.aryne amination
Akiyama, Toshiki,Arai, Masayoshi,Arisawa, Mitsuhiro,Haneoka, Hitoshi,Harada, Kazuo,Murai, Kenichi,Murakami, Yosuke,Ohki, Yuuta,Ohta, Ryousuke,Sako, Makoto,Sirimangkalakitti, Natchanun,Suzuki, Takeyuki,Takahashi, Naoyuki,Takehara, Tsunayoshi,Yamada, Makito
supporting information, p. 8131 - 8137 (2021/10/29)
We have developed a continuous microwave irradiation-assisted Buchwald-Hartwig amination using our original Pd nanoparticle catalyst with a copper plate as a co-existing metal solid. In this methodology, a microwave-controlled product selectivity was achieved between Buchwald-Hartwig amination and aryne amination performed under strongly basic conditions and at a high reaction temperature, because a polar chemical species such as Ar-Pd-halogen might be activated selectively by microwave radiation. Moreover, our catalyst could be used repeatedly over 10 times, and the amount of Pd leaching could be suppressed to a low level.
Nickel-Catalyzed Reversible Functional Group Metathesis between Aryl Nitriles and Aryl Thioethers
Delcaillau, Tristan,Boehm, Philip,Morandi, Bill
supporting information, p. 3723 - 3728 (2021/04/07)
We describe a new functional group metathesis between aryl nitriles and aryl thioethers. The catalytic system nickel/dcype is essential to achieve this fully reversible transformation in good to excellent yields. Furthermore, the cyanide- and thiol-free reaction shows high functional group tolerance and great efficiency for the late-stage derivatization of commercial molecules. Finally, synthetic applications demonstrate its versatility and utility in multistep synthesis.
