- Direct para-Selective C-H Amination of Iodobenzenes: Highly Efficient Approach for the Synthesis of Diarylamines
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Iodine(III)-mediated synthesis of 4-iodo-N-phenylaniline from iodobenzene has been achieved, and the reaction can proceed under mild conditions. A variety of functional groups were well tolerated, providing the corresponding products in moderate to good yields. The remaining iodine group provides an effective platform for converting the products into several valuable asymmetric diphenylamines. Most importantly, this reaction can be easily scaled up to the ten-gram scale, highlighting its synthetic utility. The mechanistic study revealed that the in situ generated aryl hypervalent iodine intermediate is the key factor to realize this para-selective C-H amination reaction.
- Chen, Yujie,Huang, Zhibin,Jiang, Yaqiqi,Shu, Sai,Yang, Shan,Shi, Da-Qing,Zhao, Yingsheng
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p. 8226 - 8235
(2021/06/28)
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- Acetamidoarenediazonium Salts: Opportunities for Multiple Arene Functionalization
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Unlike their ortho counterparts, meta- and para-acetamidoanilines can be converted into the corresponding acetamidoarenediazonium salts. These offer various opportunities for multiple Pd-catalyzed arene functionalization reactions, such as Matsuda-Heck-, Suzuki-Miyaura- or Fujiwara-Moritani couplings. Acetamidoarenediazonium salts, accessible from simple acetamidoanilines, are starting points for multiple Pd-catalyzed arene functionalization reactions.
- Schmidt, Bernd,Elizarov, Nelli,Riemer, Nastja,H?lter, Frank
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p. 5826 - 5841
(2015/09/15)
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- Pd-catalyzed Semmler-Wolff reactions for the conversion of substituted cyclohexenone oximes to primary anilines
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Homogeneous Pd catalysts have been identified for the conversion of cyclohexenone and tetralone O-pivaloyl oximes to the corresponding primary anilines and 1-aminonaphthalenes. This method is inspired by the Semmler-Wolff reaction, a classic method that exhibits limited synthetic utility owing to its forcing conditions, narrow scope, and low product yields. The oxime N-O bond undergoes oxidative addition to Pd0(PCy3)2, and the product of this step has been characterized by X-ray crystallography and shown to undergo dehydrogenation to afford the aniline product.
- Hong, Wan Pyo,Iosub, Andrei V.,Stahl, Shannon S.
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supporting information
p. 13664 - 13667
(2013/10/01)
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- Nickel-catalyzed hydrogenolysis of unactivated carbon-cyano bonds
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Selective hydrogenolysis of C-CN bonds can allow chemists to take advantage of ortho-directing ability, α-C-H acidity and electron withdrawing ability of the cyano group for synthetic manipulations. We have discovered hydrogenolysis of aryl and aliphatic cyanides under just 1 bar of hydrogen by using a nickel catalyst. This protocol was applied in the aryl cyanide directed functionalization reaction and α-substitution of benzyl cyanides.
- Patra, Tuhin,Agasti, Soumitra,Modak, Atanu,Maiti, Debabrata
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supporting information
p. 8362 - 8364
(2013/09/23)
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- Nickel-catalyzed Suzuki-Miyaura coupling of heteroaryl ethers with arylboronic acids
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Nickel-catalyzed Suzuki-Miyaura coupling of heteroaryl ethers with arylboronic acids was described. Selective activation of the phenol C-O bonds was achieved by converting them into the corresponding aryl 2,4-dimethoxy-1,3,5- triazine-6-yl ethers, in which aryl C-O bond could be selectively cleaved with inexpensive, air-stable NiCl2(dppf) as a catalyst. Coupling of these readily accessible heteroaryl ethers proved tolerant of extensive functional groups.
- Li, Xiao-Jian,Zhang, Jin-Ling,Geng, Yu,Jin, Zhong
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p. 5078 - 5084
(2013/06/27)
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- (NHC)palladium complexes from hydroxy-functionalized imidazolium salts as catalyst for the microwave-accelerated fluorine-free Hiyama reaction
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Palladium acetate reacts with 1-benzyl-3-(2-hydroxy-2-phenylethyl)-1H- imidazolium chloride to give the corresponding bis(carbene)palladium(II) complex 5 [(NHC)2PdCl2] by direct metalation. The X-ray diffraction structure of the complex is reported. In the presence of NaOH solution (50 % H2O, w/w) in air and under microwave irradiation, the bis(NHC)pallalium(II) complex 5 is an active precatalyst for the Hiyama coupling of aryl halides with trialkoxy(aryl)silanes, providing biaryls and heterobiaryls. For some deactivated aryl bromides and for aryl chlorides, the corresponding cross-coupling reactions require tetrabutylammonium bromide (TBAB) as additive. The fluoride-free Hiyama reactions are performed with low (NHC)palladium loadings (0.1 mol-%). The active catalyst can also be prepared in situ from Pd(OAc)2 and the corresponding imidazolium salt 4.
- Penafiel, Itziar,Pastor, Isidro M.,Yus, Miguel,Esteruelas, Miguel A.,Olivan, Montserrat,Onate, Enrique
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experimental part
p. 7174 - 7181
(2012/01/06)
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- Stille cross-coupling reactions of aryl mesylates and tosylates using a biarylphosphine based catalyst system
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A catalyst system for the Stille cross-coupling reactions of aryl mesylates and tosylates is reported. Using the combination of Pd(OAc)2, XPhos, and CsF in t-BuOH an array of aryl and heteroaryl sulfonates were successfully employed in these reactions. Morever, heteroarylstannanes, such as furyl, thienyl, and N-methylpyrrolyl, which are often prone to decomposition, were efficiently coupled under these conditions. Ortho-substitution on the stannane coupling partner was well tolerated; however, the presence of ortho substituents on the aryl sulfonates greatly reduced the efficiency of these reactions.
- Naber, John R.,Fors, Brett P.,Wu, Xiaoxing,Gunn, Jonathon T.,Buchwald, Stephen L.
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experimental part
p. 1215 - 1226
(2010/10/02)
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- A meta-selective copper-catalyzed C-H bond arylation
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For over a century, chemical transformations of benzene derivatives have been guided by the high selectivity for electrophilic attack at the ortho/para positions in electron-rich substrates and at the meta position in electron-deficient molecules. We have
- Phipps, Robert J.,Gaunt, Matthew J.
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scheme or table
p. 1593 - 1597
(2010/04/05)
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- Tandem optimization of target activity and elimination of mutagenic potential in a potent series of N-aryl bicyclic hydantoin-based selective androgen receptor modulators
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Pharmacokinetic studies in cynomolgus monkeys with a novel prototype selective androgen receptor modulator revealed trace amounts of an aniline fragment released through hydrolytic metabolism. This aniline fragment was determined to be mutagenic in an Ames assay. Subsequent concurrent optimization for target activity and avoidance of mutagenicity led to the identification of a pharmacologically superior clinical candidate without mutagenic potential.
- Hamann, Lawrence G.,Manfredi, Mark C.,Sun, Chongqing,Krystek Jr., Stanley R.,Huang, Yanting,Bi, Yingzhi,Augeri, David J.,Wang, Tammy,Zou, Yan,Betebenner, David. A.,Fura, Aberra,Seethala, Ramakrishna,Golla, Rajasree,Kuhns, Joyce E.,Lupisella, John A.,Darienzo, Celia J.,Custer, Laura L.,Price, Jennifer L.,Johnson, James M.,Biller, Scott A.,Zahler, Robert,Ostrowski, Jacek
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p. 1860 - 1864
(2008/02/04)
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