620-84-8Relevant academic research and scientific papers
Palladium(II)-acetylacetonato complexes with mesoionic carbenes: Synthesis, structures and their application in the Suzuki-Miyaura cross coupling reaction
Hettmanczyk, Lara,Schmid, Bianca,Hohloch, Stephan,Sarkar, Biprajit
, (2016)
A series of novel palladium(II) acetylacetonato complexes bearing mesoionic carbenes (MICs) have been synthesized and characterized. The synthesis of the complexes of type (MIC)Pd(acac)I (MIC = 1-mesityl-3-methyl-4-phenyl-1,2,3-triazol-5-ylidene (1), 1,4-(2,4,6-methyl)-phenyl-3-methyl-1,2,3-triazol-5-ylidene (2), 1,4-(2,6-diisopropyl)-phenyl-3-methyl-1,2,3-triazol-5-ylidene (3); acac = acetylacetonato) via direct metalation starting from the corresponding triazolium iodides and palladium(II) acetylacetonate is described herein. All complexes were characterized by 1H- and 13C-NMR spectroscopy and high resolution mass spectrometry. Additionally, two of the complexes were characterized by single crystal X-ray crystallography confirming a square-planar coordination geometry of the palladium(II) center. A delocalized bonding situation was observed within the triazolylidene rings as well as for the acac ligand respectively. Complex 2 was found to be an efficient pre-catalyst for the Suzuki-Miyaura cross coupling reaction between aryl-bromides or -chlorides with phenylboronic acid.
Synthesis of 2-methylcarbamazepine, a new internal standard for chromatographic assays of carbamazepine (Tegretol)
Patton,Dudley
, p. 257 - 262,258,261 (1979)
The synthesis of 2-methyl-5H-dibenz[b,f]azepine-5-carboxamide (2-methylcarbamazepine, 2-MCBZ), a promising internal standard for chromatographic assays of the antiepileptic agent carbamazepine is described. N-(p-tolyl)anthranilic acid was utilized as a starting material for the synthesis of a key compound, 2,9-dimethylacridine, which was converted in two steps to 2-methyl-9-hydroxymethylacridan. The acridan, in the presence of polyphosphoric acid, was ring-expanded to form 2-methyl-5H-dibenz[b,f]azepine, this latter compound being converted by conventional reactions to its 5-carbamyl derivative, 2-MCBZ.
Synthesis of 3-aryl-2-phosphinoimidazo[1,2-: A] pyridine ligands for use in palladium-catalyzed cross-coupling reactions
Tran, Ryan Q.,Jacoby, Seth A.,Roberts, Kaitlyn E.,Swann, William A.,Harris, Nekoda W.,Dinh, Long P.,Denison, Emily L.,Yet, Larry
, p. 17778 - 17782 (2019)
3-Aryl-2-phosphinoimidazo[1,2-a]pyridine ligands were synthesized from 2-aminopyridine via two complementary routes. The first synthetic route involves the copper-catalyzed iodine-mediated cyclizations of 2-aminopyridine with arylacetylenes followed by palladium-catalyzed cross-coupling reactions with phosphines. The second synthetic route requires the preparation of 2,3-diiodoimidazo[1,2-a]pyridine or 2-iodo-3-bromoimidazo[1,2-a]pyridine from 2-aminopyridine followed by palladium-catalyzed Suzuki/phosphination or a phosphination/Suzuki cross-coupling reactions sequence, respectively. Preliminary model studies on the Suzuki synthesis of sterically-hindered biaryl and Buchwald-Hartwig amination compounds are presented with these ligands.
Investigation on the coupling reactions of aryltriflates with aromatic amines: Selection of the metal catalyst
Torisawa, Yasuhiro,Hashimoto, Akihiro,Furuta, Takuya,Minamikawa, Jun-Ichi
, p. 1821 - 1824 (1997)
A simple and effective coupling reaction of aryl triflates with aniline derivatives in the presence of palladium catalyst is described, which appears to be a general and useful protocol for the preparation of functionalized arylamines starting from phenols.
On the efficiency of two-coordinate palladium(0) N-heterocyclic carbene complexes in amination and Suzuki-Miyaura reactions of aryl chlorides
Arentsen, Katherine,Caddick, Stephen,Cloke, F. Geoffrey N.
, p. 9710 - 9715 (2005)
The catalytic activity of novel two-coordinate palladium N-heterocyclic carbene complexes that differ in their steric and electronic properties is compared in catalytic amination and Suzuki-Miyaura cross-couplings.
Nickel-Catalyzed Amination of Aryl Nitriles for Accessing Diarylamines through C?CN Bond Activation
Wu, Ke,Rong, Qiang,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu,Jin, Liqun,Hu, Xinquan
, p. 4708 - 4713 (2021/08/27)
A nickel-catalyzed amination to access diarylamines has been developed through C?CN bond activation of aryl nitriles with anilines. In this developed catalytic protocol, various aromatic and heteroaromatic nitriles could be utilized as the electrophiles to couple with substituted anilines. A diversity of diarylamines were obtained in 15–95% yields. (Figure presented.).
Preparation method of secondary aromatic amine
-
Paragraph 0023-0024, (2021/03/31)
The invention provides a method for preparing secondary aromatic amine by performing a palladium-catalyzed C-N coupling reaction on (pseudo)aryl halide and (pseudo)heterocyclic aryl halide and primary(heterocyclic)aromatic amine. The method is characterized in that an alkali for promoting the reaction is an alkali metal carboxylate or an alkali metal bicarbonate.
Chitosan nanoparticles functionalized poly-2-hydroxyaniline supported CuO nanoparticles: An efficient heterogeneous and recyclable nanocatalyst for N-arylation of amines with phenylboronic acid at ambient temperature
Seyedi, Neda,Zahedifar, Mahboobeh
, (2021/07/25)
The present study aims to prepare an effective and eco-friendly nanocatalyst for the Chan–Lam coupling reaction of phenylboronic acid and amine in aerobic conditions. For this purpose, chitosan was extracted from shrimp shells waste by demineralization, deproteinization, and deacetylation processes and then converted to chitosan nanoparticles (CSN) by the ionic gelation with tripolyphosphate anions. Afterward, poly-2-hydroxyaniline (P2-HA) was grafted to chitosan nanoparticles (NPs) to employ as the support for CuO NPs. Characterization of the nanocatalyst was done using Fourier transform infrared (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), mapping, energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The CuO NPs were identified in the spherical shape with an average size of 17 nm. The prepared nanocatalyst exhibited excellent catalytic performance with a high turnover number (TON) and turnover frequency (TOF) for the Chan–Lam coupling reaction of phenyl boronic acid and amines with different electronic properties. The prepared catalyst could be readily recovered and reused for at least five runs without any noticeable change in structure and catalytic performance. Chitosan (CS) was prepared via demineralization, deproteinization, and deacetylation of shrimp shell and chitosan nanoparticles (CSN) were prepared via ionic gelation process. Polymerization of 2-HA on the CSN surface was done to increase functional groups and create active sites for CuO NPs attachments. CuO NPs-P2-HA-CSN nanocomposite has been shown high efficiently for the Chan–Lam coupling reaction.
Mediator-Enabled Electrocatalysis with Ligandless Copper for Anaerobic Chan-Lam Coupling Reactions
Walker, Benjamin R.,Manabe, Shuhei,Brusoe, Andrew T.,Sevov, Christo S.
supporting information, p. 6257 - 6265 (2021/05/07)
Simple copper salts serve as catalysts to effect C-X bond-forming reactions in some of the most utilized transformations in synthesis, including the oxidative coupling of aryl boronic acids and amines. However, these Chan-Lam coupling reactions have historically relied on chemical oxidants that limit their applicability beyond small-scale synthesis. Despite the success of replacing strong chemical oxidants with electrochemistry for a variety of metal-catalyzed processes, electrooxidative reactions with ligandless copper catalysts are plagued by slow electron-transfer kinetics, irreversible copper plating, and competitive substrate oxidation. Herein, we report the implementation of substoichiometric quantities of redox mediators to address limitations to Cu-catalyzed electrosynthesis. Mechanistic studies reveal that mediators serve multiple roles by (i) rapidly oxidizing low-valent Cu intermediates, (ii) stripping Cu metal from the cathode to regenerate the catalyst and reveal the active Pt surface for proton reduction, and (iii) providing anodic overcharge protection to prevent substrate oxidation. This strategy is applied to Chan-Lam coupling of aryl-, heteroaryl-, and alkylamines with arylboronic acids in the absence of chemical oxidants. Couplings under these electrochemical conditions occur with higher yields and shorter reaction times than conventional reactions in air and provide complementary substrate reactivity.
Cu(I)–N-heterocyclic carbene-catalyzed base free C–N bond formation of arylboronic acids with amines and azoles
Zhang, Maoyuan,Xu, Zengbing,Shi, Dabin
, (2020/12/25)
A new N-heterocyclic carbene (NHC) precursor of imidazolium chloride and its corresponding Cu(I)–NHC complex 1 was synthesized. The complex 1 was found to be a highly effective catalyst for Chan-Evans-Lam coupling of arylboronic acid with amines and azoles (including imidazole, pyrazole and triazole), without addition of base at room temperature. Various substituents on three substrates can be tolerated, giving the desired coupling products in good to excellent yields (62–94%). The method is practical and offers an alternative to the corresponding copper-catalyzed Chan-Evans-Lam process for the construction of C–N bonds.
