- An Investigation into the Electrochemical Oxidation of Some Aromatic Amines in the Room-Temperature Molten Salt System Aluminium Chloride-n-Butylpyridinium Chloride
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The electrochemical oxidation of a number of aromatic amines in the low-temperature molten salt system aluminium chloride-N-butylpyridinium chloride has been investigated.In acidic melts TPA is oxidized reversibly to its radical cation which at more positive potentials undergoes a further, chemically irreversibly oxidation to the dication of the amine.In basic melts the stability of the radical cation is reduced and it couples to form tetraphenylbenzidine which is itself further oxidized.The oxidation of the other amines was more complex as a result of their being involved in complexation equilibria with acid species in the melt.In basic melts where they were uncomplexed, their behavior was similar to that of TPA, but, in acidic melts, the amine complexes underwent irreversible two-electron oxidations to their respective dications at potentials ca. 1 V positive of the first oxidation potential of the free amine.TMB, which, depending on the melt acidity, could be present as the free amine mono or di complex, was also oxidized to its dication.The actual mechanism of this oxidation was dependent upon the melt acidity.The oxidation of TMB was also shown to be dependent upon the temperature, the TMB cation radical being stable at low temperature but becoming unstable with respect to disproportionation as the temperature was increased.
- Robinson, J.,Osteryoung, R. A.
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- Laser flash photolysis generation and kinetic studies of corrole-manganese(v)-oxo intermediates
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Corrole-manganese(V)-oxo intermediates were produced by laser flash photolysis of the corresponding corrole-manganese(IV) chlorate complexes, and the kinetics of their decay reactions in CH2Cl2 and their reactions with organic reductants were studied. The corroie ligands studied were 5,10,15-tris(pentafluorophenyl)corrole (H3TPFC), 5,10,15-triphenylcorrole (H3TPC), and 5,15-bis(pentafluorophenyl)-10- (p-methoxyphenyl)corrole (H3BPFMC). In self-decay reactions and in reactions with substrates, the order of reactivity of (Cor)MnV(O) was TPC > BPFMC > TPFC, which is inverted from that expected based on the electron-demand of the ligands. The rates of reactions of (Cor)MnV(O) were dependent on the concentration of the oxidant and other manganese species, with increasing concentrations of various manganese species resulting in decreasing rates of reactions, and the apparent rate constant for reaction of (TPFC)MnV(O) with triphenylamine was found to display fractional order with respect to the manganese-oxo species. The kinetic results are consistent in part with a reaction model involving disproportionation of (Cor)MnV(O) to give (Cor)MnIV and (Cor)MnVI(O) species, the latter of which is the active oxidant. Alternatively, the results are consistent with oxidation by (Cor)MnV(O) which is reversibly sequestered in non-reactive complexes by various manganese species.
- Zhang, Rui,Harischandra, Dilusha N.,Newcomb, Martin
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- Prevalence of the external surface over the internal pores in the spontaneous generation of tetrathiafulvalene radical cation incorporated in the novel delaminated ITQ-2 zeolite
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ITQ-2 is a novel delaminated zeolite whose crystalline sheets (2.5 nm depth) define a large external surface (～720 m2 g-1) having 12-membered ring (MR) open cups together with a reduced microporosity due to a 10 MR channel system. This feature is the reverse of that of classical zeolites (i.e., much larger internal area compared to the external surface). Herein, we have used tetrathiafulvalene and triphenylamine to probe the capability of layered ITQ-2 zeolite to generate persistent organic radical cations compared to conventional Y, mordenite and ZSM-5 zeolites as well as to Al/MCM-41 (3.2 nm diameter) and amorphous silica-alumina. By selective silylation of the external cups, it has been found that formation of a significant concentration of persistent organic radical cations in ITQ-2 is a property that occurs within the open cups of the external surface rather than inside the 10 MR pores.
- Corma,Fornes,Galletero,Garcia,Gomez-Garcia
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- A Pd/Cu-Free magnetic cobalt catalyst for C-N cross coupling reactions: synthesis of abemaciclib and fedratinib
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Herein, the synthesis of a nano-catalytic system comprising magnetic nanoparticles as the core and edible natural ligands bearing functional groups as supports for cobalt species is described. Subsequent to its characterization, the efficiency of the catalyst was investigated for C-N cross-coupling reactions using assorted derivatives of amines and aryl halides. This novel and easily accessible Pd- and Cu-free catalyst exhibited good catalytic activity in these reactions using γ-valerolactone (GVL) at room temperature; good recyclability bodes well for the future application of this strategy. The introduced catalytic system is attractive in view of the excellent efficiency in an array of coupling reactions and its versatility is illustrated in the synthesis of abemaciclib and fedratinib, which are FDA-approved new and significant anti-cancer medicinal compounds that are prepared under green reaction conditions.
- Hajipour, Abdol R.,Khorsandi, Zahra,Sarfjoo, Mohamad Reza,Varma, Rajender S.
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supporting information
p. 5222 - 5229
(2021/07/29)
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- A base-free Chan–Lam reaction catalyzed by an easily assembled Cu(II)-carboxylate metal-organic framework
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A new copper(II) metal-organic framework is constructed as a sustainable copper heterogeneous catalyst. Cu-DPTCA, with high catalytic activity, can effectively promote the Chan–Lam coupling reaction of arylboronic acids and amines without adding any base or additive.
- Ma, Ruixuan,Qin, Jianhua,Shi, Lei,Zhang, Xinhai
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p. 795 - 799
(2021/07/06)
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- Method for synthesizing organic aromatic nitrogen-containing compound by taking nitrogen as nitrogen source
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The invention provides a method for synthesizing an organic aromatic nitrogen-containing compound by taking nitrogen as a nitrogen source, and belongs to the field of organic synthesis. The invention provides a method for synthesizing an organic aromatic nitrogen-containing compound by taking nitrogen as a nitrogen source, which is characterized by comprising the following steps of: 1, reducing nitrogen by lithium powder to form lithium nitride; and 2, reacting the lithium nitride with a halogenated aromatic compound under the action of a transition metal catalyst, a ligand, alkali and a phase transfer catalyst to obtain an organic aromatic nitrogen-containing compound; wherein the two steps of reactions are completed in one pot. The method realizes the conversion of cheap nitrogen to the high-added-value aromatic nitrogen-containing compound, and also has the advantages of mild reaction conditions, good compatibility of substrate functional groups, high yield and the like.
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Paragraph 0034-0039
(2021/05/08)
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- Metal-organic frameworks derived CuONPs@C nanocatalysts for synthesizing optoelectronic triarylamine molecules
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Carbon encapsulated copper oxide nanoparticles (CuONPs@C) fabricated using copper metal organic frameworks (Cu-MOFs) used as reusable nanocatalysts in Ullmann C[sbnd]N coupling reactions for synthesizing optoelectronic triphenylamine (TPA) and carbazole (CBZ) derivatives. The formation of CuONPs in carbon matrix was confirmed by powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HR-TEM). The catalytic activity of CuONPs@C was performed with diphenylamine/carbazole with substituted aryl halides in presence of mild K2CO3 base that produced triarylamines with 63–83% yields. Carbazole triarylamines exhibited strong solid state fluorescence (Φf = 14.54–36.32%) with λmax between 370 and 420 nm.
- Kundu, Anu,Kumar, Vadivel Vinod,Anthony, Savarimuthu Philip
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- Organic light-emitting compound and preparation method and device thereof
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The invention provides an organic light-emitting compound which has a structure as shown in a formula I. By developing a hole transport material with a novel structure, the structural design direction is greatly expanded, a molecular structure with finer difference space conformation can be designed and synthesized, the structure-activity relationship can be better carded, and therefore, the hole transport material with more excellent performance is obtained. The organic light-emitting compound provided by the invention is used as a hole transport material of an organic electroluminescence device, and compared with other hole transport materials, the organic light-emitting compound has remarkably improved light-emitting efficiency and the service life. And the organic light-emitting compound has the advantages of short synthetic route, simple process, accessible raw materials and low cost, and is suitable for industrial production.
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Paragraph 0021; 0040; 0042; 0044; 0046
(2021/04/14)
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- N -Arylation of (hetero)arylamines using aryl sulfamates and carbamates via C-O bond activation enabled by a reusable and durable nickel(0) catalyst
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An effective and general aryl amination protocol has been developed using a magnetically recoverable Ni(0) based nanocatalyst. This new stable catalyst was prepared on Fe3O4@SiO2 modified by EDTA and investigated by FT-IR, EDX, TEM, XRD, DLS, FE-SEM, XPS, NMR, TGA, VSM, ICP and elemental analysis techniques. The reaction proceeded via carbon-oxygen bond cleavage of (hetero)aryl carbamates and sulfamates under simple and mild conditions without the use of any external ligands. This method demonstrated functional group tolerance in the N-arylation of various nitrogen-containing compounds as well as aliphatic amines, anilines, pyrroles, pyrazoles, imidazoles, indoles, and indazoles with good to excellent yields. Furthermore, the catalyst could be easily recovered by using an external magnetic field and directly reused at least six times without notable reduction in its activity. This journal is
- Dindarloo Inaloo, Iman,Majnooni, Sahar,Eslahi, Hassan,Esmaeilpour, Mohsen
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p. 13266 - 13278
(2020/10/07)
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- Hydrodebromination of Aromatic Bromides Catalyzed by Unsupported Nanoporous Gold: Heterolytic Cleavage of Hydrogen Molecule
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Unsupported nanoporous gold (AuNPore) is a highly efficient, practically applicable, and recyclable catalyst for hydrodebromination of aromatic bromides. The AuNPore-catalyzed hydrodebromination of aromatic bromides proceeded smoothly at relatively low hydrogen pressure and temperature to achieve good to excellent yields of the corresponding non-bromine variants. The selective hydrodebromination reaction occurred exclusively in the coexistence of chlorine atom. For the first time, a mechanistic study revealed that the H?H bond splits in a heterolysis manner on the surface of AuNPore to generate Au?H hydride species.
- Bao, Ming,Feng, Xiujuan,Yamamoto, Yoshinori,Zhang, Sheng,Zhao, Yuhui
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p. 4951 - 4957
(2020/09/09)
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- Synthesis of hexahydrophenanthridines via the tandem reaction of benzynes
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A tandem insertion-cyclization reaction between carbocyclic β–amino ketones and benzynes has been described, producing hexahydrophenanthridines in moderate to high yields.
- Li, Wen-Juan,Pian, Ji-Xin,Gu, Cheng-Zhi,Dai, Bin,He, Lin
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- Synthesis of unsymmetrically substituted triarylaminesviaacceptorless dehydrogenative aromatization using a Pd/C andp-toluenesulfonic acid hybrid relay catalyst
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An efficient and convenient procedure for synthesizing triarylamines based on a dehydrogenative aromatization strategy has been developed. A hybrid relay catalyst comprising carbon-supported Pd (Pd/C) andp-toluenesulfonic acid (TsOH) was found to be effective for synthesizing a variety of triarylamines bearing different aryl groups starting from arylamines (diarylamines or anilines), using cyclohexanones as the arylation sources under acceptorless conditions with the release of gaseous H2. The proposed reaction comprises the following relay steps: condensation of arylamines and cyclohexanones to produce imines or enamines, dehydrogenative aromatization of the imines or enamines over Pd nanoparticles (NPs), and elimination of H2from the Pd NPs. In this study, an interesting finding was obtained indicating that TsOH may promote the dehydrogenation.
- Jin, Xiongjie,Koizumi, Yu,Mizuno, Noritaka,Nozaki, Kyoko,Takayama, Satoshi,Yamaguchi, Kazuya,Yatabe, Takafumi
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p. 4074 - 4084
(2020/05/25)
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- Integrating CuO?Fe2O3 Nanocomposites and Supramolecular Assemblies of Phenazine for Visible-Light Photoredox Catalysis
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A photoredox catalytic ensemble consisting of CuO-Fe2O3 nanocomposites and oligomeric derivative of phenazine has been developed. The prepared system acts as an efficient photoredox catalyst for C?N bond formation reaction via SET mechanism under ‘green’ conditions (aerial environment, mixed aqueous media, recyclable), requiring less equivalents of base and amine substrate. The present study demonstrates the significant role of supramolecular assemblies as photooxidants and reductants upon irradiation and their important contribution towards the activation of the metallic centre through energy transfer and electron transfer pathways. The potential of oligomer 4: CuO-Fe2O3 has also been explored for C?C bond formation reactions via the Sonogashira protocol.
- Kaur, Lovjot,Deol, Harnimarta,Kumar, Manoj,Bhalla, Vandana
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supporting information
p. 892 - 898
(2020/03/04)
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- Organic electroluminescent compound, preparation method thereof and organic electroluminescent device
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The invention discloses an organic electroluminescent compound, and the structural formula of the organic electroluminescent compound is shown in the specification. The invention also discloses a preparation method of the organic electroluminescent compound, and the organic electroluminescent compound is used for preparing an organic electroluminescent device, and the prepared organic electroluminescent device shows high luminous efficiency and long service life. Driving voltage is reduced.
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Paragraph 0035-0036; 0038
(2020/12/30)
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- Organic electroluminescent compound as well as preparation method and application thereof
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The invention discloses an organic electroluminescent compound, which has a structural general formula shown as a general formula 1, wherein X is a chemical bond, or O, S, SO2, C (R4) (R5), N (R6), Si(R7) (R8), Sn (R9) (R10) or Ge (R11) (R12); R1-R3 is a C1-C30 alkyl group or a C6-C30 aryl group or a C3-C30 heteroaryl group; or connecting with an adjacent substituent to form a single ring or a multi-ring; R to R are a C - C alkyl C C aryl group and a C -C heteroaryl group; or connecting with an adjacent substituent to form a single ring or amulti-ring; and L is a substituted or non-substituted C6-C30 aryl group. The organic electroluminescent compound has the advantages of short synthetic route, simple process, accessible raw materials and low cost, and is suitable for industrial production. The organic electroluminescent compound prepared by the invention has the advantages of high quantum efficiency, long service life and the like.
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Paragraph 0046-0047; 0049
(2020/12/31)
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- Direct Installation of a Silyl Linker on Ready-Made NHC Ligands: Immobilized NHC-Pd Complex for Buchwald-Hartwig Amination
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An immobilized N-heterocyclic carbene (NHC)-Pd complex was prepared via direct silyl linker installation onto the imidazole backbone of commercially available 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) ligand. The IPr backbone was lithiated and treated with Me2SiCl2 to afford ClMe2Si-IPr, which reacted with [Pd(π-allyl)Cl]2 to yield a ClMe2Si-IPr-Pd complex, and this was immobilized on Wang resin. The immobilized NHC-Pd complex facilitated quantitative Buchwald-Hartwig amination of aryl chlorides within 10 min, even at a low Pd loading of 0.2 mol %. The catalyst could be removed from the reaction mixture by simple filtration, and Pd leaching into the reaction medium was suppressed to below 1 ppm.
- Mizusaki, Tomoteru,Matsumoto, Kazuhiro,Takeuchi, Katsuhiko,Fukaya, Norihisa,Takagi, Yukio,Choi, Jun-Chul
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supporting information
p. 1872 - 1876
(2019/05/07)
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- A new strategy to design a graphene oxide supported palladium complex as a new heterogeneous nanocatalyst and application in carbon–carbon and carbon-heteroatom cross-coupling reactions
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The palladium nanoparticles were successfully stabilized with an average diameter of 6–7?nm through the coordination of palladium and terpyridine-based ligands grafted on graphene oxide surface. The graphene oxide supported palladium nanoparticles were thoroughly characterized and applied as an efficient heterogeneous catalyst in carbon–carbon (Suzuki-Miyaura, Mizoroki-Heck coupling reactions) and carbon–heteroatom (C-N and C-O) bond-forming reactions. The catalyst was simply recycled from the reaction mixture and was reused consecutive four times with small drop in catalytic activity.
- Bahrami, Kiumars,Targhan, Homa
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- Ullmann-type: N-arylation of anilines with alkyl(aryl)sulfonium salts
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A palladium/copper-cocatalyzed Ullmann-type N-arylation of anilines using alkyl(aryl)sulfonium triflates as arylation reagents has been accomplished. The reaction enabled Caryl-S bond cleavage over Calkyl-S bond breakage of alkyl(aryl)sulfoniums by Pd(P(tBu)3)2/CuI and gave the corresponding N-arylated products in good to high yields. It was also significant that the reactions of aniline with asymmetric butyl(mesityl)(aryl)sulfonium triflates showed excellent selectivity, in which the aryl groups other than the bulky and electron-rich mesityl moieties were transformed.
- Tian, Ze-Yu,Zhang, Cheng-Pan
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p. 11936 - 11939
(2019/10/11)
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- Palladium nanoparticles supported on cysteine-functionalized MNPs as robust recyclable catalysts for fast O- and N-arylation reactions in green media
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A magnetically robust recyclable nanocatalyst was fabricated by immobilizing of Pd onto the surface of cysteine-functionalized magnetic nanoparticles (MNPs?Cys-Pd). This nanocatalyst was characterized using various techniques such as FT-IR, XRD, TEM, SEM, EDX, VSM, and ICP. The application of catalyst (MNPs?Cys-Pd) was investigated for O-arylation and N-arylation reactions. This phosphine-free complex was found as highly efficient heterogeneous catalyst in green media and mild reaction conditions. In addition, it gave excellent recyclability without significant deactivation after ten cycles.
- Hajipour, Abdol R.,Khorsandi, Zahra,Fatemeh Mohammadi Metkazini
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- Direct Synthesis of Diphenylamines from Phenols and Ammonium Formate Catalyzed by Palladium
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Arylamines are commercially and synthetically useful compounds with a wide variety of applications. Their preparation has been traditionally achieved using metal-catalyzed C?N coupling reactions with aryl halides. In this work, 17 different diarylamines are prepared from phenols by using ammonium formate as the aminating reagent. Phenolic compounds are more desirable feedstocks, owing to their availability from lignin, making them valuable biorenewable alternatives to aryl halides. Ammonium formate is found to be a convenient surrogate for ammonia and a useful aminating reagent for phenols. Diarylamine products are obtained in good to excellent yields while only water and CO2 are generated as byproducts of the transformation.
- Dominguez-Huerta, Alejandra,Perepichka, Inna,Li, Chao-Jun
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p. 2999 - 3002
(2019/06/13)
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- Diamines as interparticle linkers for silica-titania supported PdCu bimetallic nanoparticles in Chan-Lam and Suzuki cross-coupling reactions
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A series of highly efficient amine functionalized SiO2-TiO2 supported bimetallic PdCu catalysts with varied metal composition have been synthesized. Ethane-1,2-diamine, butane-1,4-diamine and hexane-1,6-diamine were employed as interparticle linkers for amine functionalization of a SiO2-TiO2 support material so as to study the effect of pendant chain length on stabilization and immobilization of bimetallic nanoparticles. The shortest carbon chain length on the support provided the best results, which may be due to the trapping of metal nanoparticles more efficiently by the basic nitrogen sites. The catalytic activities of these materials were evaluated for C-N and C-C coupling reactions. The most active catalyst, Pd1Cu1@12DA-STS, was characterized by various techniques including SEM, HR-TEM, ICP-AES, XRD, FTIR, EDX, CHN analysis and TGA studies. Moreover, the synthesized catalyst was found to be recyclable for up to five runs without significant loss of activity.
- Jamwal, Babita,Kaur, Manpreet,Sharma, Harsha,Khajuria, Chhavi,Paul, Satya,Clark
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p. 4919 - 4928
(2019/03/26)
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- Hydrodehalogenation of Aryl Halides through Direct Electrolysis
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A catalyst- and metal-free electrochemical hydrodehalogenation of aryl halides is disclosed. Our reaction by a flexible protocol is operated in an undivided cell equipped with an inexpensive graphite rod anode and cathode. Trialkylamines nBu3N/Et3N behave as effective reductants and hydrogen atom donors for this electrochemical reductive reaction. Various aryl and heteroaryl bromides worked effectively. The typically less reactive aryl chlorides and fluorides can also be smoothly converted. The utility of our method is demonstrated by detoxification of harmful pesticides and hydrodebromination of a dibrominated biphenyl (analogues of flame-retardants) in gram scale.
- Ke, Jie,Wang, Hongling,Zhou, Liejin,Mou, Chengli,Zhang, Jingjie,Pan, Lutai,Chi, Yonggui Robin
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supporting information
p. 6911 - 6914
(2019/05/10)
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- C?N Cross-Coupling Reactions Under Mild Conditions Using Singlet Di-Radical Nickel(II)-Complexes as Catalyst: N-Arylation and Quinazoline Synthesis
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Herein we report a cost-effective synthetic approach for C?N cross-coupling reactions of a broad array of nitrogen nucleophiles and aryl halides under mild conditions. These reactions are catalyzed by an inexpensive, air-stable, earth-abundant and easy-to-prepare singlet di-radical nickel(II)-catalyst containing two antiferromagnetically coupled single-electron oxidized diiminosemiquinonato type ligands. This protocol provides an alternative method for C?N cross-coupling reactions avoiding nickel(0)/nickel(II) or nickel(I)/nickel(III) redox processes via cooperative participation of metal and ligand-centered redox events. Besides a wide range of N-arylation reactions, by judicious choice of aryl halides and nitrogen nucleophiles the synthesis of a variety of polysubstituted quinazolines has been achieved in moderate to good yields under relatively mild reaction conditions. Our catalyst has been found to be almost equally effective in quinazoline synthesis via C?N cross-coupling of (i) 2-bromobenzylamine with benzamide, and (ii) 2-bromobenzylbromide with amidine. Control experiments and DFT studies were performed to improve the understanding of the cooperative participation of ligand and metal (nickel)-centered redox events during oxidative addition/reductive elimination processes of the catalytic cycle and to shed light on the plausible mechanistic pathway of the C?N cross-coupling reactions. (Figure presented.).
- Sikari, Rina,Sinha, Suman,Chakraborty, Gargi,Das, Siuli,van Leest, Nicolaas Petrus,Paul, Nanda D.
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supporting information
p. 4342 - 4353
(2019/08/21)
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- Solvent-free mechanochemical Buchwald-Hartwig amination of aryl chlorides without inert gas protection
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A solvent-free Buchwald-Hartwig amination had been developed under high-speed ball-milling conditions, which afforded the desired products with moderate to high yields. The addition of sodium sulfate was found to be crucial for improving both the performance and the reproducibility. Comparative solvent-free stirring experiments implicated the importance of mechanical interaction for the transformation, and the inert gas was proved to be unnecessary for this amination.
- Shao, Qiao-Ling,Jiang, Zhi-Jiang,Su, Wei-Ke
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supporting information
p. 2277 - 2280
(2018/05/16)
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- Nano CoCuFe2O4-catalyzed coupling reaction of arylboronic acid with amines and thiols: An atom-economic and ligand-free route to access unsymmetrical amines and sulfides
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An efficient protocol was developed for the nano CoCuFe2O4-catalyzed C-N and C-S bond formation. By this catalytic system, both amine and sulfide-based structural motifs were formed efficiently in aryl halide-free route. The amination reaction of phenyl boronic acid with various types of amines was conducted under ligand-free conditions, in ethanol as a green solvent at 60°C. Unsymmetrical diaryl/aryl alkyl sulfide synthesis via the coupling reaction of arylboronic acids with thiols was also conducted. The nano cobalt-copper ferrite was used as a heterogenous efficient, inexpensive, magnetically separable and recyclable catalyst that can be used for several cycles.
- Moghaddam, Firouz Matloubi,Pourkaveh, Raheleh,Gholamtajari, Milad
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- Transition-Metal-Free N-Arylation of Amines by Triarylsulfonium Triflates
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A simple and efficient method for transition-metal-free N-arylation of various amines by triarylsulfonium triflates is described. Both aliphatic and aromatic amines were smoothly converted at 80 °C in the presence of tBuOK or KOH to give the corresponding mono N-arylated products in good to high yields. The molar ratios of the reactants and the choice of bases had a big effect on the reaction. When a large excess of [Ph3S][OTf] and tBuOK were employed for primary amines under the standard conditions, the bis(N-phenyl) products were predominantly formed. This method was also applicable to the synthesis of bioactive N-phenyl amino acid derivatives. The control experiments, the deuterium labelling study, and the presence of regioisomers of N-arylated products when using 4-substituted triarylsulfonium triflates suggested that the reaction might proceed through an aryne intermediate. The present protocol demonstrated that triarylsulfonium salts are versatile arylation reagents in the construction of CAr?N bonds.
- Tian, Ze-Yu,Ming, Xiao-Xia,Teng, Han-Bing,Hu, Yu-Tian,Zhang, Cheng-Pan
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supporting information
p. 13744 - 13748
(2018/09/14)
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- Air-Stable Blue Phosphorescent Tetradentate Platinum(II) Complexes as Strong Photo-Reductant
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Strong photo-reductants have applications in photo-redox organic synthesis involving reductive activation of C?X(halide) and C=O bonds. We report herein air-stable PtII complexes supported by tetradentate bis(phenolate-NHC) ligands having peripheral electron-donating N-carbazolyl groups. Photo-physical, electrochemical, and computational studies reveal that the presence of N-carbazolyl groups enhances the light absorption and redox reversibility because of its involvement into the frontier MOs in both ground and excited states, making the complexes robust strong photo-reductant with E([Pt]+/*) over ?2.6 V vs. Cp2Fe+/0. The one-electron reduced [Pt]? species are stronger reductants with EPC([Pt]0/?) up to ?3.1 V vs. Cp2Fe+/0. By virtue of the strong reducing nature of these species generated upon light excitation, they can be used in light-driven reductive coupling of carbonyl compounds and reductive debromination of a wide range of unactivated aryl bromides.
- Li, Kai,Wan, Qingyun,Yang, Chen,Chang, Xiao-Yong,Low, Kam-Hung,Che, Chi-Ming
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supporting information
p. 14129 - 14133
(2018/10/15)
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- Chitosan-Supported Ni particles: An Efficient Nanocatalyst for Direct Amination of Phenols
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A practical method for the direct amination of phenols using 2,4,6-trichloro-1,3,5-triazine (TCT) as an efficient promotor for the activation of phenols in the presence of an efficient and recyclable heterogeneous catalyst prepared by immobilization of nickel particles on triazole modified chitosan is described. This heterogeneous catalyst has demonstrated a promising activity for the conversion of phenolic compounds to their corresponding amine under mild conditions. Moreover, the obtained catalyst can be reused in five consecutive runs with consistent catalytic activity.
- Hajipour, Abdol R.,Abolfathi, Parisa
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- Ultrafine hybrid Cu2O-Fe2O3 nanoparticles stabilized by hexaphenylbenzene-based supramolecular assemblies: A photocatalytic system for the Ullmann-Goldberg coupling reaction
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Ultrafine hybrid Cu2O-Fe2O3 NPs have been prepared using the supramolecular assemblies of hexaphenylbenzene (HPB) derivative 3 as nanoreactors and stabilizers. The as-prepared hybrid Cu2O-Fe2O3 NPs serve as an efficient and recyclable photocatalytic system for carrying out C-N coupling between aryl halides and various amines (aliphatic, aromatic and N-heterocyclic) at room temperature in mixed aqueous media under visible light irradiation. Amazingly, Cu2O-Fe2O3 NPs also exhibited high efficiency in the reactions involving the synthesis of biologically important N-substituted carbazole derivatives. The work being presented in this article demonstrates the preparation of a 'dip strip' coated with the as-prepared catalytic system and utilization of this paper strip as a recyclable and portable heterocatalytic system for carrying out the Ullmann-Goldberg coupling.
- Singh, Gurpreet,Kumar, Manoj,Bhalla, Vandana
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p. 5346 - 5357
(2018/12/05)
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- A green and mild procedure to selective synthesis of diarylamine via domino reaction of aryl halides and arginine catalyzed by magnetic-MOF
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Efficient and selective direct synthesis of diarylamines from aryl halides and arginine as a nitrogen-donor reagent is reported. Arginine, which is an oral supplement, acts as a useful nitrogen source donor in the copper-catalyzed reaction. Fe3O4/Cu3(BTC)2, which was easily separated and recycled with a magnet, improved the rate and facilitation of the synthesis of diarylamines selectively. The introduction of a new and available N-source, simple magnetic separation process, normal atmospheric conditions, and excellent yields under mild reaction conditions are other important features of this work.
- Soleiman-Beigi, Mohammad,Mohammadi, Fariba
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- A mechanical to urge the enters the carbon - [...] forming method (by machine translation)
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The invention discloses a mechanical to urge the enters the carbon - [...] forming method, said method comprising: in order to type 2 shown in formulae of organic amine 3 shown the chlorinated aromatic hydrocarbon as the raw material, the catalyst, ligand, in the presence of alkali and additive, the reaction is carried out by the mechanical grinding method, after the reaction mixture after the separation and purification, obtains the type 1 compound shown; in the present invention relates to mechanical grinding promotion to the chlorinated aromatic hydrocarbon as the substrate of the Buchwald - Hartwig reaction mainly adopts the organic phosphonate ligands, in the palladium catalyst under the action of the organic amine compound with the chlorinated aromatic hydrocarbon of the between the coupling, so as to obtain high yield of the target product, the majority of the reaction can be 90% or more yield. The mild reaction conditions, can be in the 1 - 2 H to complete the reaction. (by machine translation)
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Paragraph 0042; 0043; 0044; 0046; 0061
(2018/09/21)
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- METHOD FOR PRODUCING AROMATIC AMINE
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PROBLEM TO BE SOLVED: To provide a method for producing aromatic amine solving the problem that, in the case a halogen atom is selected as the well-known leaving group of a coupling reaction raw material compound, since harmful halogen waste is by-produced after reaction, waste liquid treatment is complicated and an environmental load is high and further solving the problem that, in the case a trifluoromethanesulfonyloxy group is selected as the leaving group, an environmental load upon the production of a raw material compound having a trifluoromethanesulfonyloxy group is high, and also, the production operation is complicated. SOLUTION: Provided is a method for producing an aromatic amine compound characterized in that an aromatic nitro compound and an amine compound are brought into cross coupling reaction in the presence of a metal catalyst. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPO&INPIT
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Paragraph 0047; 0048
(2018/06/13)
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- Electron-Catalyzed Coupling of Magnesium Amides with Aryl Iodides
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An electron was found to catalyze the coupling of magnesium diarylamides with aryl iodides giving triarylamines through a radical-anion intermediate. The transformation requires no transition metal catalysts or additives, and a wide array of products are formed in good-to-excellent yields.
- Kiriyama, Kazuya,Okura, Keisho,Tamakuni, Fumiko,Shirakawa, Eiji
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supporting information
p. 4519 - 4522
(2018/03/13)
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- Nickel Dual Photoredox Catalysis for the Synthesis of Aryl Amines
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In this work, a new dual photoredox nickel catalysis system has been utilized for the synthesize of aryl amines. Previously, our group has shown that a nickel catalyst in conjunction with a photosensitizer and a sacrificial electron donor can cross-couple C-C bonds via photoredox-assisted reductive coupling. Here we have built upon that system to develop a redox-neutral cross-coupling system for the formation of C-N bonds. The catalytic system is composed of just a nickel cross-coupling catalyst, a Ru photocatalyst, and base and is capable of coupling amines with aryl halides in good to excellent yields. Furthermore, it was found that these reactions are functional under ambient conditions with catalyst loadings of 1 mol %. Spectroscopic studies provide support that this amination mechanism proceeds via a nitrogen-based radical intermediate. This N-radical mechanism offers direct synthetic access to di- and triaryl amines from nickel photocatalysis.
- Key, Ryan J.,Vannucci, Aaron K.
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p. 1468 - 1472
(2018/05/23)
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- Sonogashira-Hagihara and Buchwald-Hartwig cross-coupling reactions with sydnone and sydnone imine derived catalysts
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Seven different palladium complexes of sydnones and sydnone imines and a co-catalyst system consisting of lithium sydnone-4-carboxylate and Pd(PPh3)4 catalyzed Sonogashira-Hagihara reactions between (hetero)- aromatic bromides and 2-methylbut-3-yn-2-ol (52 examples, up to 100% yield). The co-catalyst system and a sydnone Pd complex were also tested in Buchwald-Hartwig reactions (9 examples, up to 100% yield). (Equation Presented).
- Lücke, Ana-Luiza,Pruschinski, Lucas,Freese, Tyll,Schmidt, Andreas
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supporting information
p. 94 - 104
(2020/08/26)
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- Synthetic method for tris(4-tetrazolylphenyl)amine
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The invention discloses a synthetic method for tris(4-tetrazolylphenyl)amine, and belongs to the field of material chemistry. The technical scheme is as follows: under alkaline conditions, diphenylamine is reacted with a benzene halide to obtain triphenylamine, the triphenylamine is subjected to a substitution reaction with iodine to form tris(4-iodophenyl)amine, the tris(4-iodophenyl)amine is reacted with CuCN to form tris(4-cyanophenyl)amine, and finally the tris(4-cyanophenyl)amine is reacted with sodium azide to form the tris(4-tetrazolylphenyl)amine. A porous material constructed by a reaction of the prepared tris(4-tetrazolylphenyl)amine and a metal not only has the stability of carboxylic acid porous skeletons, but also realizes the functionalization in the pore channels, and the size of the pore channels can reach a mesoporous size; and the adsorption capacity of specific sulfur-containing small molecules by the tris(4-tetrazolylphenyl)amine further shows the potential application value of the tris(4-tetrazolylphenyl)amine, and the tris(4-tetrazolylphenyl)amine has meaning for development of high-performance petrochemical products.
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Paragraph 0023
(2018/05/01)
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- MANUFACTURING METHOD OF AROMATIC AMINE COMPOUND, NOVEL AROMATIC AMINE COMPOUND, FLUORESCENT EMISSION MATERIAL AND ULTRAVIOLET ABSORBER
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PROBLEM TO BE SOLVED: To provide a manufacturing method of an aromatic amine compound by a Buchwald-Hartwig reaction using a novel palladium catalyst, especially a manufacturing method of the aromatic amine compound capable of providing an object compound at high efficiency even with a substrate which does not proceed a reaction favorably in prior art, further a manufacturing method of the aromatic amine compound capable of providing a novel aromatic amine compound having no synthetic example previously, a novel fluorescent emission material and an ultraviolet absorber consisting of a novel aromatic amine compounds, a 5-aminothiazole compound. SOLUTION: The manufacturing method of an aromatic amine compound includes reacting an aromatic halogen compound and an amine compound in the presence of palladium nanoparticles and a base with a phosphine compound as a protectant to obtain the aromatic amine compound. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0092; 0094; 0095; 0096
(2018/09/26)
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- Arylation of aniline and amines by Pd-(N-Heterocyclic carbene) complexes
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Aminoarenes constitute valuable building blocks in organic synthesis and an essential skeleton ubiquitously found in ligands, agrochemicals, and pharmaceuticals. This synopsis presents recent amination methods using nitrogen-heteroatom bonds as a powerful and versatile platform to rapidly synthesize diverse aminoarenes, with transition-metal catalyzed arene C-H amination. The Buchwald-Hartwig amination has been investigated theoretically and experimentally to examine the scope of possible bases under different reaction conditions. We report examples of the palladium NHC (N-heterocyclic carbene) catalyzed amination of aryl halides with anilines and amines in the presence of dimethoxyethane solvent and potassium tertiary-butoxide as a base.
- ?ahin, Neslihan,Dü?ünceli, Serpil Demir,?zdemir, ?smail
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p. 1506 - 1517
(2017/08/02)
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- N/O-doped carbon as a "solid ligand" for nano-Pd catalyzed biphenyl- and triphenylamine syntheses
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A series of N/O-doped porous carbon supported nanopalladium catalysts have been successfully prepared, in which the N/O doped carbons were controllably produced via polypyrrole/furan synthesis followed by carbonization. These catalysts exhibit good performance in biphenylamine and triphenylamine syntheses with nitrobenzene and cyclohexanone as starting materials. Their catalytic activity can be tuned efficiently by the N/O functional groups on the carbon surface. TEM, XRD, XPS and laser Raman methods were applied to probe the structure of these catalysts. These results indicate that the Pd nanoparticles were supported on N/O-doped porous carbon via the "coordination" between Pd nanoparticles and N/O functional groups including O-CO, CN and tertiary nitrogen, and better catalytic performance was obtained if carbon with the highest N-species loading was used as the support. In addition, a mechanistic study proved that the reaction starts with the catalytic reduction of nitrobenzene with cyclohexanone as the hydrogen source. During this reaction, aniline was formed and the cyclohexanone was transformed into phenol. Then biphenylamine and triphenylamine were generated through the reaction of aniline and cyclohexanone. This work should facilitate the controllable preparation of carbon supported nanocatalysts with specific activity, and open up a promising pathway for the development of new methodologies for N-containing fine chemical synthesis.
- Pang, Shaofeng,Zhang, Yujing,Huang, Yongji,Yuan, Hangkong,Shi, Feng
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p. 2170 - 2182
(2017/07/24)
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- Synthesis of Triarylamines via Sequential C-N Bond Formation
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A one-pot domino N-arylation protocol is described using diaryliodonium reagents under copper catalysis. The reaction uses both aryl groups of the diaryliodonium reagent to generate triarylamines starting from simple anilines, representing an atom-economical preparation of an important class of organic material building blocks.
- Modha, Sachin G.,Popescu, Mihai V.,Greaney, Michael F.
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p. 11933 - 11938
(2017/11/24)
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- Buchwald–Hartwig Amination of Nitroarenes
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The Buchwald–Hartwig amination of nitroarenes was achieved for the first time by using palladium catalysts bearing dialkyl(biaryl)phosphine ligands. These cross-coupling reactions of nitroarenes with diarylamines, arylamines, and alkylamines afforded the corresponding substituted arylamines. A catalytic cycle involving the oxidative addition of the Ar?NO2 bond to palladium(0) followed by nitrite/amine exchange is proposed based on a stoichiometric reaction.
- Inoue, Fumiyoshi,Kashihara, Myuto,Yadav, M. Ramu,Nakao, Yoshiaki
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supporting information
p. 13307 - 13309
(2017/10/17)
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- Radical Hydrodehalogenation of Aryl Bromides and Chlorides with Sodium Hydride and 1,4-Dioxane
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A practical method for radical chain reduction of various aryl bromides and chlorides is introduced. The thermal process uses NaH and 1,4-dioxane as reagents and 1,10-phenanthroline as an initiator. Hydrodehalogenation can be combined with typical cyclization reactions, proving the nature of the radical mechanism. These chain reactions proceed by electron catalysis. DFT calculations and mechanistic studies support the suggested mechanism.
- Hokamp, Tobias,Dewanji, Abhishek,Lübbesmeyer, Maximilian,Mück-Lichtenfeld, Christian,Würthwein, Ernst-Ulrich,Studer, Armido
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supporting information
p. 13275 - 13278
(2017/10/09)
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- PdCl2(Ph3P)2/Salicylaldimine Catalyzed Diarylation of Anilines with Unactivated Aryl Chlorides
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Triphenylphosphine and salicylaldimine could be used as a mixed ligand system to obtain a high catalytic activity for palladium catalyzed diarylation of primary anilines with unactivated aryl chlorides by the synergistic effect of ligands. The activity and selectivity of the catalytic system could be improved by modifying the structure of salicylaldimine. In refluxing o-xylene, PdCl2(Ph3P)2 with 2,5-ditrifluoromethyl N-phenylsalicylaldimine as a coligand shows high efficiency for the diarylation of various anilines. The catalytic system shows good toleration for the steric hindrance of the substrates. The facile catalytic system works as well on the multiple arylation of 1,1′-biphenyl- 4,4′-diamine with aryl chlorides to afford N,N,N′,N′-tetraaryl-1,1′-biphenyl-4,4′-diamines which are important intermediates of organic light emitting diode (OLED) hole transport materials.
- Tao, Xiaochun,Li, Lei,Zhou, Yu,Qian, Xuanying,Zhao, Min,Cai, Liangzhen,Xie, Xiaomin
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supporting information
p. 1749 - 1754
(2017/10/06)
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- Stereoelectronic control of oxidation potentials of 3,7-bis(diarylamino)phenothiazines
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The influence of diarylamino (Ar2N-) substituents on the oxidation potential of 3,7-bis(diarylamino)phenothiazines (Ar2N)2-PTZ (1a-f, a: carbazolyl; b: dihydrodibenzoazepinyl; c: dibenzoazepinyl; d: diphenylamino; e: phenothiazinyl; and f: phenoxazinyl) is investigated, where the Ar2N-substituent sequence a→f is aligned in the increasing order of their electron-donating ability. Interestingly, a different sequence of electron-donating ability for Ar2N-substituents was observed for the oxidation potentials of (Ar2N)2-PTZ: 1a (Eox1 = +0.35 V vs. Fc/Fc+) > 1f (+0.30 V) > 1e (+0.15 V) > 1d (-0.05 V) > 1c (-0.19 V) > 1b (-0.22 V). The observed sequence can be explained by the stereoelectronic effect of the Ar2N-substituents to stabilize (Ar2N)2-PTZ+. Clear-cut examples are observed in the crystal structure of 1c+ and 1e+, for which coplanar conformation is observed between the PTZ+-plane and the planes of the sp2-hybridized nitrogen atoms in Ar2N-substituents through a large conformational change during the oxidation process of (Ar2N)2-PTZ.
- Karimata, Ayumu,Suzuki, Shuichi,Kozaki, Masatoshi,Okada, Keiji
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p. 56144 - 56152
(2017/12/26)
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- Solvent-Free Buchwald-Hartwig (Hetero)arylation of Anilines, Diarylamines, and Dialkylamines Mediated by Expanded-Ring N-Heterocyclic Carbene Palladium Complexes
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A highly efficient solvent-free protocol for the Buchwald-Hartwig (hetero)arylation of anilines, diarylamines, and dialkylamines mediated by the expanded-ring N-heterocyclic carbene palladium complex (THP-Dipp)Pd(cinn)Cl [THP-Dipp = 1,3-bis(2,6-diisopropylphenyl)-3,4,5,6-tetrahydropyrimidin-2-ylidene; cinn = cinnamyl, 3-phenylallyl] was developed. The catalytic protocol was efficient for the coupling of amines and (hetero)aryl chlorides and bromides bearing donor, acceptor, and bulky substituents.
- Topchiy, Maxim A.,Dzhevakov, Pavel B.,Rubina, Margarita S.,Morozov, Oleg S.,Asachenko, Andrey F.,Nechaev, Mikhail S.
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p. 1908 - 1914
(2016/04/20)
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- Nano PdAu Bimetallic Alloy as an Effective Catalyst for the Buchwald-Hartwig Reaction
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It is highly challenging but desirable to develop efficient heterogeneous catalysts for C-Cl bond activation in coupling reactions. Here, we succeeded in synthesizing bimetallic Pd-Au nanoparticles through a convenient one-pot wet chemical route. The composition and alloyed structure of the as-prepared nanoparticles were fully characterized. We have evaluated the catalytic activity of these Pd-Au alloy catalysts in Buchwald-Hartwig reactions of aryl chlorides. The excellent catalytic activity of the as-obtained Pd-Au nanoparticles indicates that exploiting the catalytic power of nano-alloy catalysts could enable effective C-Cl bond activation suitable for cross-coupling reactions.
- Chen, Zheng,Wang, Shuo,Lian, Chao,Liu, Yuxi,Wang, Dingsheng,Chen, Chen,Peng, Qing,Li, Yadong
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p. 351 - 355
(2016/05/19)
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- An efficient heterogeneous ligand free C-N coupling reaction catalyzed by palladium supported on magnetic nanoparticles
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The catalytic activity of palladium supported on magnetic nanoparticles in the amination coupling reaction of different nitrogen containing substrates with aryl halides was investigated. C-N bond formation was achieved in moderate to excellent yields and the catalyst could be separated by magnetic decantation.
- Rafiee, Ezzat,Ataei, Ali,Joshaghani, Mohammad
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p. 219 - 222
(2015/12/31)
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- One-Step Pyrolysis Preparation of 1.1.1 Oriented Gold Nanoplatelets Supported on Graphene and Six Orders of Magnitude Enhancement of the Resulting Catalytic Activity
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Pyrolysis of chitosan films containing Au3+ renders 1.1.1 oriented Au nanoplatelets (20 nm lateral size, 3-4 nm height) on a few layers of N-doped graphene (${overline {{rm{Au}}} }$/fl-G), while the lateral sides were 0.0.1 oriented. Comparison of the catalytic activity of ${overline {{rm{Au}}} }$/fl-G films with powders of unoriented Au NPs supported on graphene showed that ${overline {{rm{Au}}} }$/fl-G films exhibit six orders of magnitude enhancement for three gold-catalyzed reactions, namely, Ullmann-like homocoupling, C-N cross coupling, and the oxidative coupling of benzene to benzoic acid. This enhancement is the result of the defined morphology, facet orientation of Au nanocrystals, and strong gold-graphene interaction.
- Primo, Ana,Esteve-Adell, Ivan,Coman, Simona N.,Candu, Natalia,Parvulescu, Vasile I.,Garcia, Hermenegildo
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p. 607 - 612
(2016/02/27)
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- C–N cross-coupling on supported copper catalysts: The effect of the support, oxidation state, base and solvent
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A series of supported copper catalysts at two different loadings (1 and 2?wt%) have been prepared by deposition precipitation on various supports including TiO2, ZnO, Al2O3 and active carbon and submitted or not to reductive treatments to favor the increase in population of Cu(I). The samples have been characterized by textural measurements, electron microscopy and spectroscopic techniques including EPR and XPS, concluding the presence of dispersed copper oxides on the support with small particle size and contrasting prevalence of Cu(II) or Cu(I). The catalytic activity of all these catalysts for the C–N coupling of aniline and bromobenzene has been evaluated. A strong influence of the support, copper oxidation state, solvent, nature of the base was observed, the optimal conditions being the use of ZnO or TiO2 as supports and toluene/dioxane as solvent and EtOK as base. t-C5H11OK as base in either THF or toluene give rise to the formation of t-C5H11 phenyl ether in some extent. The catalyst undergoes deactivation during the reaction, but about 88% of the activity of the fresh sample could be regained by dioxane washings before reuse. XPS indicates that the most likely origin of catalyst deactivation is adsorption on the copper catalyst surface of KBr and inorganic salts formed as byproducts during the reaction.
- Tirsoaga, Alina,Cojocaru, Bogdan,Teodorescu, Cristian,Vasiliu, Florin,Grecu, Maria Nicoleta,Ghica, Daniela,Parvulescu, Vasile I.,Garcia, Hermenegildo
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p. 205 - 220
(2016/08/04)
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- A triazine-phosphite polymeric ligand bearing cage-like P,N-ligation sites: An efficient ligand in the nickel-catalyzed amination of aryl chlorides and phenols
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A novel P,N-ligand was introduced for efficient Ni-catalyzed amination of aryl chlorides. Reaction of cyanuric acid (1,3,5-triazine-2,4,6-triol) and trichlorophosphine (PCl3) resulted in the production of a new porous material (TPPM) containing triazine rings with phosphite moieties in a sheet morphology. Cavities in the prepared compound create sites on the surface of the material with appropriate ligation character to coordinate with metals for catalytic purposes. The nickel-catalyzed amination of aryl chlorides and of phenols in their 2,4,6-triaryloxy-1,3,5-triazine (TAT) protected form were efficiently accomplished in the presence of this easily prepared and reusable P,N-ligand under mild reaction conditions. More importantly, TPPM was reusable for 5 iterations following this protocol without significantly decreasing in its activity.
- Panahi, Farhad,Roozbin, Fatemeh,Rahimi, Sajjad,Moayyed, Mohammadesmaeil,Valaei, Aria,Iranpoor, Nasser
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supporting information
p. 80670 - 80678
(2016/10/12)
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- A 1 - (2- [...] ) b cyclohexyl phosphine and its preparation method and application (by machine translation)
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The invention provides 1-(2-arylindenyl) dicyclohexylphosphine which takes a good catalytic effect in carbon-nitrogen coupling reaction of chlorinated or brominated aromatic hydrocarbons and diphenylamine and has the general formulas shown in the specification. According to the preparation method of 1-(2-arylindenyl) dicyclohexylphosphine, 2-aryl indene serving as a raw material reacts with n-butyllithium in the presence of high-purity nitrogen to obtain 1-(2-arylindenyl) dicyclohexylphosphine. 1-(2-arylindenyl) dicyclohexylphosphine and the preparation method and application thereof have the beneficial effects that A, B, C, D, E and F can exist in the air stably; a catalyst consisting of a compound D and palladium dibenzylacetone can catalyze reactions between various chlorinated aromatic hydrocarbons and diphenylamine and the highest yield is high up to 82%; the reactions between brominated aromatic hydrocarbons with high steric hindrance and diphenylamine can be catalyzed by the catalyst and the highest yield is high up to 85%; the reactions between chlorinated or brominated heterocyclic aromatic hydrocarbons and diphenylamine can be catalyzed by the catalyst and the highest yield is high up to 62%.
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Paragraph 0062-0067
(2016/12/01)
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- Biaryl Phosphine Based Pd(II) Amido Complexes: The Effect of Ligand Structure on Reductive Elimination
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Kinetic studies conducted under both catalytic and stoichiometric conditions were employed to investigate the reductive elimination of RuPhos (2-dicyclohexylphosphino-2′,6′-diisopropoxybiphenyl) based palladium amido complexes. These complexes were found to be the resting state in Pd-catalyzed cross-coupling reactions for a range of aryl halides and diarylamines. Hammett plots demonstrated that Pd(II) amido complexes derived from electron-deficient aryl halides or electron-rich diarylamines undergo faster rates of reductive elimination. A Hammett study employing SPhos (2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl) and analogues of SPhos demonstrated that electron donation of the lower aryl group is key to the stability of the amido complex with respect to reductive elimination. The rate of reductive elimination of an amido complex based on a BrettPhos-RuPhos hybrid ligand (2-(dicyclohexylphosphino)-3,6-dimethoxy-2′,6′-diisopropoxybiphenyl) demonstrated that the presence of the 3-methoxy substituent on the "upper" ring of the ligand slows the rate of reductive elimination. These studies indicate that reductive elimination occurs readily for more nucleophilic amines such as N-alkyl anilines, N,N-dialkyl amines, and primary aliphatic amines using this class of ligands.
- Arrechea, Pedro Luis,Buchwald, Stephen L.
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supporting information
p. 12486 - 12493
(2016/10/07)
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