85448-89-1Relevant academic research and scientific papers
N-Heterocyclic Carbene Palladium(II) Amine Complexes: The Role of Primary Aryl- or Alkylamine Binding and Applications in the Buchwald-Hartwig Amination Reaction
Hsu, Yu-Cheng,Chen, Ming-Tsz
supporting information, (2021/12/24)
N-heterocyclic carbene-palladium(II) amine complexes bearing primary aryl- or alkylamines were synthesized. The prepared complexes were characterized by single crystal X-ray diffraction as well as NMR spectroscopy. These complexes exhibited good catalytic activities for the Buchwald-Hartwig amination reaction of aryl chlorides to afford arylated anilines under mild conditions. All reactions were carried out in air and all starting materials were used as supplied without purification. 21 expected coupling products were obtained in moderate to high yields under optimum conditions.
Light-Promoted C–N Coupling of Aryl Halides with Nitroarenes
Li, Gang,Yang, Liu,Liu, Jian-Jun,Zhang, Wei,Cao, Rui,Wang, Chao,Zhang, Zunting,Xiao, Jianliang,Xue, Dong
supporting information, p. 5230 - 5234 (2021/02/05)
A photochemical C–N coupling of aryl halides with nitroarenes is demonstrated for the first time. Catalyzed by a NiII complex in the absence of any external photosensitizer, readily available nitroarenes undergo coupling with a variety of aryl halides, providing a step-economic extension to the widely used Buchwald–Hartwig C–N coupling reaction. The method tolerates coupling partners with steric-congestion and functional groups sensitive to bases and nucleophiles. Mechanistic studies suggest that the reaction proceeds via the addition of an aryl radical, generated from a NiI/NiIII cycle, to a nitrosoarene intermediate.
Continuous Synthesis of Aryl Amines from Phenols Utilizing Integrated Packed-Bed Flow Systems
Ichitsuka, Tomohiro,Kobayashi, Shū,Koumura, Nagatoshi,Sato, Kazuhiko,Takahashi, Ikko
, p. 15891 - 15896 (2020/07/13)
Aryl amines are important pharmaceutical intermediates among other numerous applications. Herein, an environmentally benign route and novel approach to aryl amine synthesis using dehydrative amination of phenols with amines and styrene under continuous-flow conditions was developed. Inexpensive and readily available phenols were efficiently converted into the corresponding aryl amines, with small amounts of easily removable co-products (i.e., H2O and alkanes), in multistep continuous-flow reactors in the presence of heterogeneous Pd catalysts. The high product selectivity and functional-group tolerance of this method allowed aryl amines with diverse functional groups to be selectively obtained in high yields over a continuous operation time of one week.
Aryl-Diadamantyl Phosphine Ligands in Palladium-Catalyzed Cross-Coupling Reactions: Synthesis, Structural Analysis, and Application
Sinai, ádám,Simkó, Dániel Cs.,Szabó, Fruzsina,Paczal, Attila,Gáti, Tamás,Bényei, Attila,Novák, Zoltán,Kotschy, András
supporting information, p. 1122 - 1128 (2020/03/03)
Synthesis, temperature-dependent NMR structure investigation and utilization of a new, stable and easily accessible aryl-diadamantylphosphine ligand family is reported. The bulky and electron-rich phosphorus center of the ligand enhances the catalytic activity of palladium in cross-coupling reactions of sterically demanding ortho-substituted aryl halides. In our study, we demonstrated the synthetic applicability of the new phosphine ligands in Buchwald-Hartwig and tosyl hydrazone coupling reactions.
Palladate Precatalysts for the Formation of C-N and C-C Bonds
Zinser, Caroline M.,Warren, Katie G.,Nahra, Fady,Al-Majid, Abdullah,Barakat, Assem,Islam, Mohammad Shahidul,Nolan, Steven P.,Cazin, Catherine S. J.
, p. 2812 - 2817 (2019/08/12)
A series of imidazolium-based palladate precatalysts has been synthesized and the catalytic activity of these air- and moisture-stable complexes evaluated as a function of the nature of the imidazolium counterion. These precatalysts can be converted under
Nickel-catalyzed N-arylation of amines with arylboronic acids under open air
Ando, Shin,Hirota, Yurina,Matsunaga, Hirofumi,Ishizuka, Tadao
supporting information, p. 1277 - 1280 (2019/04/10)
In this study, a well-defined, novel NHC-Ni complex was developed and used to catalyze the N-arylation of alkyl- and arylamines with arylboronic acids in a rare version of Chan-Lam coupling. Although the same coupling using copper catalysts has been widely studied, the nickel-catalyzed version is rare and normally requires 10–20 mol% catalyst loading. This novel NHC-Ni complex in combination with 4,4′-dimethyl-2,2′-bipyridine, however, proved to be an effective catalyst that lowered the required catalyst loading to only 2.0 mol%.
Nickel Dual Photoredox Catalysis for the Synthesis of Aryl Amines
Key, Ryan J.,Vannucci, Aaron K.
, p. 1468 - 1472 (2018/05/23)
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.
"on Water" Promoted Ullmann-Type C-N Bond-Forming Reactions: Application to Carbazole Alkaloids by Selective N-Arylation of Aminophenols
Chakraborti, Gargi,Paladhi, Sushovan,Mandal, Tirtha,Dash, Jyotirmayee
, p. 7347 - 7359 (2018/07/29)
The Ullmann-type cross coupling of a variety of aromatic, aliphatic amines with aryl halides is reported using a CuI-based catalytic system in combination with an easily accessible prolinamide ligand in aqueous media. The method is mild and tolerant to air, moisture, and a wide range of functional groups, providing a novel way to access a variety of aminated products. Secondary amines like heteroaromatic amines and nucleobases have also been used, affording the corresponding coupling products in good to excellent yields. Moreover, this method has been employed for chemoselective C-N arylation of aminophenols and further utilized for the synthesis of carbazole natural products, avoiding the protection and deprotection steps.
Synthesis of N-heterocyclic carbene-Pd(II) complexes and their catalytic activity in the Buchwald-Hartwig amination of aryl chlorides
Zhang, Zhi-Mao,Gao, Yu-Jue,Lu, Jian-Mei
, p. 7308 - 7314 (2017/12/01)
Novel N-heterocyclic carbene-palladium(II) complexes using 2-picolinic acid as the ancillary ligand have been successfully developed under mild conditions. Their catalytic activity in organic synthesis has been initially tested in the Buchwald-Hartwig amination of secondary and primary amines with aryl chlorides. Various substituents on both substrates can be tolerated, giving the desired coupling products in good to almost quantitative yields. The minimum catalyst loading can be 0.01 mol%, implying their potential application toward industrial processes.
The solid copper-mediated C-N cross-coupling of phenylboronic acids under continuous flow conditions
Bao, Jennifer,Tranmer, Geoffrey K.
, p. 654 - 657 (2016/01/26)
We have developed two general methods for the C-N cross-coupling of phenylboronic acids with amines using solid copper flow reactors, in combination with an oxidant. We have developed one method for a C-N arylation reaction which employs a solid copper coil reactor, in combination with tert-butyl peroxybenzoate, to give products in moderate isolated yields. We have also developed a general method for the C-N cross coupling of phenylboronic acids using a column packed with solid copper powder, in combination with acetic acid and TEMPO, to give products in isolated yields in excess of 75+%. We have also applied our general copper powder method to generate a library of products which highlights the utility of solid copper flow reactors for C-N cross coupling reactions, generating 16 examples in good yields. Mechanistic implications and future directions are also discussed.
