- N-Heterocyclic Carbene Palladium(II) Amine Complexes: The Role of Primary Aryl- or Alkylamine Binding and Applications in the Buchwald-Hartwig Amination Reaction
-
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.
- Hsu, Yu-Cheng,Chen, Ming-Tsz
-
supporting information
(2021/12/24)
-
- Light-Promoted C–N Coupling of Aryl Halides with Nitroarenes
-
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.
- 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)
-
- Aryl-Diadamantyl Phosphine Ligands in Palladium-Catalyzed Cross-Coupling Reactions: Synthesis, Structural Analysis, and Application
-
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.
- 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)
-
- Continuous Synthesis of Aryl Amines from Phenols Utilizing Integrated Packed-Bed Flow Systems
-
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.
- Ichitsuka, Tomohiro,Kobayashi, Shū,Koumura, Nagatoshi,Sato, Kazuhiko,Takahashi, Ikko
-
p. 15891 - 15896
(2020/07/13)
-
- Palladate Precatalysts for the Formation of C-N and C-C Bonds
-
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
- 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)
-
- Nickel-catalyzed N-arylation of amines with arylboronic acids under open air
-
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%.
- Ando, Shin,Hirota, Yurina,Matsunaga, Hirofumi,Ishizuka, Tadao
-
supporting information
p. 1277 - 1280
(2019/04/10)
-
- Nickel Dual Photoredox Catalysis for the Synthesis of Aryl Amines
-
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.
-
p. 1468 - 1472
(2018/05/23)
-
- "on Water" Promoted Ullmann-Type C-N Bond-Forming Reactions: Application to Carbazole Alkaloids by Selective N-Arylation of Aminophenols
-
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.
- Chakraborti, Gargi,Paladhi, Sushovan,Mandal, Tirtha,Dash, Jyotirmayee
-
p. 7347 - 7359
(2018/07/29)
-
- Synthesis of N-heterocyclic carbene-Pd(II) complexes and their catalytic activity in the Buchwald-Hartwig amination of aryl chlorides
-
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.
- Zhang, Zhi-Mao,Gao, Yu-Jue,Lu, Jian-Mei
-
p. 7308 - 7314
(2017/12/01)
-
- Synthesis of N-heterocyclic carbene-PdCl2-(iso)quinoline complexes and their application in arylamination at low catalyst loadings
-
A new type of N-heterocyclic carbene-PdCl2-(iso)quinoline complexes 3 were successfully achieved in acceptable to good yields from easily available starting materials under mild conditions, and their structures were unambiguously confirmed using X-ray single crystal diffraction. Furthermore, their catalytic activity toward Buchwald-Hartwig arylamination of aryl chlorides with primary and secondary amines was fully tested. Under the optimal reaction conditions, the expected arylated amines can be obtained in high to excellent yields at low catalyst loadings (0.005-0.05 mol%). It may be worth noting here that comparison of these complexes with other well-defined and easily available NHC-Pd(ii) complexes bearing different N-containing ancillary ligands was also carried out, showing their superior catalytic activity over all others.
- Liu, Feng,Zhu, Yi-Ran,Song, Lu-Gan,Lu, Jian-Mei
-
p. 2563 - 2571
(2016/03/01)
-
- Synthesis and characterization of N-heterocyclic carbene-palladium(II) chlorides-1-methylindazole and -1-methylpyrazole complexes and their catalytic activity toward C-N coupling of aryl chlorides
-
A series of N-heterocyclic carbene-palladium(ii) chlorides-1-methylindazole and -1-methylpyrazole complexes was successfully synthesized and fully characterized by X-ray single crystal diffraction. In addition, initial investigations of their catalytic activity showed that they were efficient catalysts in the C-N coupling of primary and secondary amines with aryl chlorides at low catalyst loadings.
- Zhao, Xiao-Yun,Zhou, Quan,Lu, Jian-Mei
-
p. 24484 - 24490
(2016/03/15)
-
- An easily available N-heterocyclic carbene–palladium(II) catalyst for Buchwald–Hartwig amination of aryl chlorides
-
Abstract: An easily available N-heterocyclic carbene–palladium(II) complex was found to be an efficient catalyst for the Buchwald–Hartwig amination of aryl chlorides. Both secondary and primary amines were tolerated under the same reaction conditions. Under the optimal conditions, all reactions proceeded successfully to give the desired products in good to high yields within hours. Graphical Abstract: [Figure not available: see fulltext.]
- Wang, Tao,Xu, Kai,Liu, Lantao,Xie, Huanping,Li, Ying,Zhao, Wen-Xian
-
p. 525 - 529
(2016/07/20)
-
- The solid copper-mediated C-N cross-coupling of phenylboronic acids under continuous flow conditions
-
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.
- Bao, Jennifer,Tranmer, Geoffrey K.
-
p. 654 - 657
(2016/01/26)
-
- A tuned bicyclic proazaphosphatrane for catalytically enhanced n-arylation reactions with aryl chlorides
-
The N-arylation of various amines with aryl chlorides proceeded in good-to-excellent yields in the presence of P[N{(p-NMe2)C6H4CH2}CH2CH2]3N (1e, a new electron-rich proazaphosphatrane ligand) and small amounts of Pd2(dba)3 (dba = dibenzylideneacetone). This catalytic system was also very effective for the synthesis of carbazoles. An efficient palladium-catalyzed N-arylation reaction of amines under mild conditions with a tuned bicyclic proazaphosphatrane has been developed.
- Kim, So Han,Kim, Min,Verkade, John G.,Kim, Youngjo
-
p. 1954 - 1960
(2015/03/18)
-
- Solvent-free N-arylation of amines with arylboronic acids under ball milling conditions
-
Solvent-free coupling reactions of arylboronic acids with various amines were presented under ball milling conditions, achieving the aromatic amine coupling products with yields ranging from moderate to good. This type of mechano-chemistry exhibited advantages of solvent-free property, high efficiency, simple work-up procedure and eco-friendliness. This journal is the Partner Organisations 2014.
- Zhu, Xingyi,Zhang, Qihong,Su, Weike
-
p. 22775 - 22778
(2014/06/23)
-
- Efficient catalytic aryl amination of bromoarenes using 3-iminophosphine palladium(II) chloride
-
While pursuing the development of new hydroamination catalysts, a 3-iminophosphine palladium(II) chloride complex [(3IP)PdCl2] was synthesized that has subsequently proven to be an effective precatalyst for the aryl amination of bromoarenes. This (3IP)PdCl2 complex has been utilized in the catalytic aryl amination of both bromobenzene and bromopyridine derivatives, specifically yielding excellent activity in coupling reactions involving bromobenzene, 4-bromotoluene, and 2-bromopyridine. Using a standard set of catalytic conditions, many alkyl and aryl amines have been investigated as coupling partners in the aryl amination of bromoarenes. In general, secondary alkyl amines and ortho-substituted anilines proved to be the best substrates for this reaction, commonly giving quantitative conversion to products, while primary amines and other anilines gave only poor to moderate results. Catalytic screening data, product yields, and full characterization of isolated products are included.
- Samblanet, Danielle C.,Schmidt, Joseph A. R.
-
p. 7 - 18,12
(2012/12/12)
-
- Palladium- and nickel-catalyzed aminations of aryl imidazolylsulfonates and sulfamates
-
A nickel complex derived from dppf, along with NaOt-Bu as the base, allowed for challenging aminations of aryl sulfamates. An improved functional group tolerance is observed in novel palladium-catalyzed aminations of imidazolylsulfonates with rac-BINAP as the ligand.
- Ackermann, Lutz,Sandmann, Rene,Song, Weifeng
-
supporting information; experimental part
p. 1784 - 1786
(2011/06/10)
-
- Preparation of anionic phosphine ligands in situ for the palladium-catalyzed Buchwald/Hartwig amination reactions of aryl halides
-
2-Phenylindenyl phosphine ligand can be changed into anionic phosphine ligand in situ and utilized in the palladium-catalyzed Buchwald/Hartwig amination reactions in DME, providing good to excellent yields of amination products from aryl chlorides, bromides and iodides. 31P NMR studies show that the resonance for the anionic phosphine appeared between those of the (2-phenylindenyl)-dicyclohexyl phosphonium salt and (2-phenylindenyl)dicyclohexylphosphine. The calculated results were consistent with the experimental results.
- Chen, Lei,Yu, Guang-Ao,Li, Fang,Zhu, Xiaolei,Zhang, Bei,Guo, Rui,Li, Xiaozhi,Yang, Qihua,Jin, Shan,Liu, Chenchen,Liu, Sheng-Hua
-
experimental part
p. 1768 - 1775
(2010/08/03)
-
- An efficient palladium-catalysed amination of aryl chlorides in presence of 1,3-bis-(2,6-diisopropylphenyl)imidazolinium chloride
-
1,3-bis-(2,6-diisopropylphenyl)imidazolinium chloride (SIPr·HCl), a precursor for an N-heterocyclic carbene, was examined as a pro-ligand in C-N coupling reactions. Thus SIPr·HCl associated with a palladium catalyst was found to be efficient for the amination of aryl chlorides under mild conditions.
- Shen, Huafeng,Zhang, Zhong-Ping,Li, Jing-Hua
-
experimental part
p. 163 - 166
(2010/07/08)
-
- METHOD FOR MAKING BIARYL COMPOUNDS, COMPOUNDS MADE BY THE METHOD, AND METHOD FOR THEIR USE
-
Certain disclosed embodiments of the present invention concern a method for making biaryl compounds by combining a diene with a dienophile under reaction conditions that facilitate a Diels-Alder reaction. Certain embodiments are particularly directed to making a tetra-ortho-substituted biaryl compounds. The disclosed method may involve using novel dienes, dienophiles, or both. Similarly, certain of the biaryl compounds are novel compounds too. Additional disclosed embodiments concern a method for making useful compounds by first making a Diels-Alder adduct. The Diels-Alder adduct is then further modified or coupled to other compounds. The method can be used to make carbazoles, such as Siamenol. Disclosed biaryl compounds are useful for a number of applications, such as pharmacophores and organocatalysts.
- -
-
Page/Page column 83
(2009/01/23)
-
- Synthesis of tetra-ortho-substituted, phosphorus-containing and carbonyl-containing biaryls utilizing a Diels-Alder approach
-
The application of the Diels-Alder approach to biaryls (DAB) is described for the synthesis of tetra-ortho-substituted biaryl compounds containing orthogonally functionalized substituents. The syntheses of phosphorus- containing, disubstituted alkynes and
- Ashburn, Bradley O.,Carter, Rich G.,Zakharov, Lev N.
-
p. 9109 - 9116
(2008/02/09)
-
- Cu(I)-mediated reductive amination of boronic acids with nitroso aromatics.
-
[reaction: see text] A mild method for the reductive amination of aryl boronic acids with nitroso aromatic compounds is reported. This C-N bond formation is mediated by a stoichiometric amount of CuCl as both a catalyst and a reducing agent. Alternatively, 10% Cu(I)-3-methylsalicylate (CuMeSal) catalyzes the same reaction in the presence of either ascorbic acid or hydroquinone as the terminal reducing agent. Diarylamines bearing a variety of functional groups can be obtained in good yields.
- Yu, Ying,Srogl, Jiri,Liebeskind, Lanny S
-
p. 2631 - 2634
(2007/10/03)
-
- Scope and limitations of Pd2(dba)3/P(i-BuNCH 2CH2)3N-catalyzed Buchwald-Hartwig amination reactions of aryl chlorides
-
Proazaphosphatrane ligands in combination with Pd2(dba) 3 generate highly active catalysts for Buchwald-Hartwig amination of aryl chlorides. In particular, commercially available P(i-BuNCH 2-CH2)3N is a highly general and efficient ligand, allowing the coupling of an electronically diverse set of aryl chlorides, including chloropyridines, with a wide variety of amines using 1 mol % of Pd at 100 °C. Either a 1:1 or 2:1 ratio of ligand to Pd was found to be effective. This catalyst system performs exceptionally well for sterically hindered substrates, even with only 0.25 mol % of Pd. It is shown that NaOH can also be used as the base (instead of NaO-t-Bu) allowing functionalized substrates to participate in these reactions.
- Urgaonkar, Sameer,Verkade, John G.
-
p. 9135 - 9142
(2007/10/03)
-
- P[N(i-Bu)CH2CH2]3N: A versatile ligand for the Pd-catalyzed amination of aryl chlorides
-
(Matrix presented) Palladium-catalyzed amination reactions of aryl chlorides with amines proceeded in the presence of the bicyclic triaminophosphine P[N(i-Bu)CH2CH2]3N to afford the corresponding arylamines in good to excellent yields. Electron-poor, electron-neutral, and electron-rich aryl chlorides all participated with equal ease.
- Urgaonkar, Sameer,Nagarajan,Verkade, John G.
-
p. 815 - 818
(2007/10/03)
-
- P(i-BuNCH2CH2)3N: An effective ligand in the palladium-catalyzed amination of aryl bromides and iodides
-
It is shown that the bicyclic triaminophosphine P(i-BuNCH2CH2)3N serves as an effective ligand for the palladium-catalyzed amination of a wide array of aryl bromides and iodides. Other bicyclic or acyclic triaminophosphines, even those of similar basicity and/or bulk, were inferior.
- Urgaonkar, Sameer,Nagarajan,Verkade
-
p. 452 - 459
(2007/10/03)
-
- Copper-catalyzed amination of aryl halides: Single-step synthesis of triarylamines
-
A simple and efficient methodology for the synthesis of triarylamines in a single step has been demonstrated using a ligand-free CuI catalyst and potassium tertiary butoxide as the base. Use of chelating ligands leads to the formation of triarylamine derivatives selectively (95% yield) with high catalytic activity.
- Kelkar, Ashutosh A.,Patil, Nandkumar M.,Chaudhari, Raghunath V.
-
p. 7143 - 7146
(2007/10/03)
-
- Nickel(0)/dihydroimidazol-2-ylidene complex catalyzed coupling of aryl chlorides and amines
-
A general and simple nickel-catalyzed coupling of aryl chlorides and amines is reported. The scope and limitations of the coupling process using Ni(0), 1,3-bis(2,6-diisopropylphenyl)dihydroimidazol-2-ylidene, and NaO-t-Bu as base were investigated. Secondary cyclic and acyclic amines and anilines provided the arylamine coupling products in good to excellent yields. Compared to palladium-catalyzed aminations, this procedure offers an alternative route to N-substituted anilines starting from readily available aryl chlorides.
- Desmarets, Christophe,Schneider, Raphael,Fort, Yves
-
p. 3029 - 3036
(2007/10/03)
-
- An improved method for the palladium-catalyzed amination of aryl iodides
-
Aryl iodides are coupled with amines to give the corresponding arylamines in high yield in the presence of palladium, a suitable ligand, and NaOt-Bu. Functionalized aryl iodides give good yields of the corresponding arylamines when Cs2CO3 is substituted as the base.
- Ali,Buchwald
-
p. 2560 - 2565
(2007/10/03)
-
- Nickel-catalyzed amination of aryl chlorides
-
Aryl chlorides are converted to aniline derivatives using catalytic amounts of Ni(COD)2 (COD = 1,5-cyclooctadiene) and DPPF (DPPF = 1,1'- bis(diphenylphosphino)ferrocene) or 1,10-phenanthroline in the presence of sodium tert-butoxide. This procedure has a broad substrate scope: electron- rich or electron-poor aryl chlorides, as well as chloropyridine derivatives, can be combined with primary and secondary amines to give the desired aryl amine products in moderate to excellent yields. Additionally, a procedure which utilizes the air-stable precatalysts (DPPF)NiCl2 or (1,10- phenanthroline)NiCl2 is also described.
- Wolfe, John P.,Buchwald, Stephen L.
-
p. 6054 - 6058
(2007/10/03)
-