77232-13-4Relevant academic research and scientific papers
Heterogeneous gold(I)-catalyzed cyclization between ynals and amidines: An efficient and practical synthesis of 2,4-disubstituted pyrimidines
Jiang, Minhua,Nie, Quan,Cai, Mingzhong
, p. 2488 - 2500 (2019/07/12)
A novel and highly efficient heterogeneous gold(I)-catalyzed cyclization between ynals and amidines has been developed that proceeds smoothly under mild conditions and provides a general and practical method for the synthesis of a wide variety of 2,4-disu
Selective Methylation of Arenes: A Radical C?H Functionalization/Cross-Coupling Sequence
Serpier, Fabien,Pan, Fei,Ham, Won Seok,Jacq, Jér?me,Genicot, Christophe,Ritter, Tobias
supporting information, p. 10697 - 10701 (2018/07/31)
A selective, nonchelation-assisted methylation of arenes has been developed. The overall transformation, which combines a C?H functionalization reaction with a nickel-catalyzed cross-coupling, offers rapid access to methylated arenes with high para selectivity. The reaction is amenable to late-stage methylation of small-molecule pharmaceuticals.
Facile one-pot nanocatalysts encapsulation of palladium-NHC complexes for aqueous Suzuki-Miyaura couplings
Chen, Chao,Zheng, Qing,Ni, Shengliang,Wang, Hangxiang
, p. 4624 - 4630 (2018/03/21)
Organic transformations using water as the solvent have been the focus of intense investigation. We herein present a strategy that uses simple nanoparticle encapsulation to fabricate water-soluble nanocatalysts (NCs) for aqueous cross-coupling reactions. To achieve this goal, three types of N-heterocyclic carbene (NHC)-palladium (Pd) complexes (i.e., 1b, 2b, and 3b) with the chemical formula [PdL(CH3CN)Cl]PF6 (where L is a bidentate pyridine- or pyrimidine-bearing NHC ligand) have been synthesized, and their structures were characterized by NMR spectroscopy and X-ray crystallography. Exploiting a facile one-pot encapsulation process, the water-insoluble Pd-NHC complexes can be integrated into the hydrophobic cores of micelles composed of an amphiphilic copolymer. These water-dispersed nanoparticles exhibited excellent catalytic activity in aqueous Suzuki-Miyaura couplings. Among these NCs, 3b-NC, bearing a mesityl moiety on its NHC ligand, was found to be the most active catalyst under the tested reaction conditions. More impressively, 3b-NC can be reused for at least five cycles without substantial loss of catalytic activity.
Ruthenium-Catalyzed meta-Selective C?H Mono- and Difluoromethylation of Arenes through ortho-Metalation Strategy
Li, Zhong-Yuan,Li, Liang,Li, Qi-Li,Jing, Kun,Xu, Hui,Wang, Guan-Wu
supporting information, p. 3285 - 3290 (2017/03/16)
The first example for the ruthenium-catalyzed ligand-directed meta-selective C?H mono- and difluoromethylation is developed, affording a variety of new meta-mono- and difluoromethylated 2-phenylpyridines, 2-phenylpyrimidines, and 1-phenylpyrazoles in moderate-to-good yields. This new transformation exhibits broad substrate scope, good functional group tolerance, and high efficiency, and offers a practical approach to synthesize mono- and difluoromethylated arenes. Mechanistic studies indicate that a reaction pathway involving palladium-initiated radical species is involved in the catalytic cycle. The new dual catalytic system consisting of compatible ruthenium(II) and palladium(0) complexes enables the key processes of C?H activation and mono-/difluoromethyl-radical formation to occur and achieves the meta-selective functionalization efficiently. In addition, the present protocol can also be extended to non-fluoromethylation.
AMVN-initiated expedient synthesis of biaryls by the coupling reaction of unactivated arenes and heteroarenes with aryl iodides
Bhakuni, Bhagat Singh,Yadav, Abhimanyu,Kumar, Shailesh,Kumar, Sangit
, p. 827 - 836 (2014/02/14)
The role of radical initiators AMVN and AIBN has been studied in the potassium tert-butoxide mediated biaryl coupling reaction of aryl iodides with unactivated arenes. Radical initiator AMVN promoted carbon-carbon bond formation expeditiously from aryl iodide having various groups such as amino, methoxy, fluoro, methyl, and trifluoromethyl and arenes in the presence of potassium tert-butoxide (4 equiv.) at 110 °C in 2-5 h. Substituted arenes such as toluene, xylene, anisole, and fluorobenzene also proceeded to form biaryls under AMVN-initiated reaction conditions. Moreover naphthalene, pyridine, pyrimidine, and pyridazine also coupled with aryl iodides and produced biaryls in 41-82% yields. It seems that AMVN initiates the formation of the aryl radical, which enters the radical chain reaction. The generated aryl radical may combine with the arene leading to a biaryl radical, which upon protonation gives the biphenyl radical anion and tert-butanol. The biphenyl radical anion finally reacts with the aryl iodide generating the aryl radical and thus completes the radical chain reaction with concomitant release of biphenyl.
Systematic evaluation of HOMO energy levels for efficient dye regeneration in dye-sensitized solar cells
Funaki, Takashi,Otsuka, Hiromi,Onozawa-Komatsuzaki, Nobuko,Kasuga, Kazuyuki,Sayama, Kazuhiro,Sugihara, Hideki
supporting information, p. 15945 - 15951 (2015/03/03)
Thirty ruthenium complexes of the types [Ru(tctpy)(C^N)NCS] and [Ru(tctpy)(N^O)NCS] (C^N = cyclometalating ligand and N^O = pyridinecarboxylate and its derivatives) were synthesized and evaluated to identify the highest occupied molecular orbital (HOMO) energy level (EHOMO) for efficient dye regeneration in dye-sensitized solar cells. EHOMOof these complexes was systematically tuned by changing the electron-donating ability of the C^N and N^O ligands. For complexes with an EHOMOin the potential range more negative than 0.5 V vs. a saturated calomel electrode (SCE), the incident photon-to-current conversion efficiency (IPCE) increased with a positive shift in EHOMObut could not exceed 70%, suggesting that rapid dye regeneration is difficult. On the other hand, high IPCEs above 70% were often observed for complexes with an EHOMOmore positive than 0.5 V vs. SCE. It is thus concluded that there is a threshold for efficient electron transfer near 0.5 V vs. SCE (ΔG2≈ 0.3 eV) for the series of these sensitizers. This journal is
Ruthenium-catalyzed double-fold C-H tertiary alkoxycarbonylation of arenes using di-tert-butyl dicarbonate
Hong, Xiaohu,Wang, Hao,Liu, Bingxin,Xu, Bin
supporting information, p. 14129 - 14132 (2014/12/11)
An efficient ruthenium-catalyzed double-fold C-H alkoxycarbonylation of arenes was developed using di-tert-butyl dicarbonate as the tertiary esterification reagent, which leads to a direct route to valuable 2,6-dicarboxylated products. This journal is
Copper-catalyzed aromatic C-H bond halogenation with lithium halides under aerobic conditions
Mo, Song,Zhu, Yamin,Shen, Zengming
supporting information, p. 2756 - 2760 (2013/05/08)
A concise and practical Cu-catalyzed protocol for the preparation of chloro- and bromoarenes via C-H bond activation has been developed. The advantages of this strategy are the employment of cheap Cu(NO3) 2·3H2O, LiX and O2, and its compatibility with both electron-donating and electron-withdrawing substituents on aryl rings.
Nickel-catalyzed cross-coupling of arene-or heteroarenecarbonitriles with aryl-or heteroarylmanganese reagents through C-CN bond activation
Liu, Ning,Wang, Zhong-Xia
supporting information; experimental part, p. 1641 - 1645 (2012/07/31)
The nickel-catalyzed cross-coupling reaction of arene- or heteroarenecarbonitriles with aryl- or heteroarylmanganese reagents via C-CN bond activation has been developed. Both electron-rich and electron-deficient nitriles can be employed as the electrophilic substrates. The reaction tolerates a range of functional groups and aromatic heterocycles. Copyright
Trinuclear copper(I) complex of 1,3-bis(2-pyridinylmethyl)imidazolylidene as a carbene-transfer reagent for the preparation of catalytically active nickel(II) and palladium(II) complexes
Chen, Chao,Qiu, Huayu,Chen, Wanzhi
scheme or table, p. 4166 - 4172 (2012/01/06)
Reactions of 1,3-bis(pyridin-2-ylmethyl)-1H-imidazol-3-ium hexafluorophosphate, ([HL1](PF6), L1 = 1,3-bis(pyridin-2-ylmethyl) imidazolylidene) and 1,3-bis(pyridin-2-ylmethyl)-1H-benzimidazol-3-ium hexafluorophosphate ([HL2](PF6), L2 = 1,3-bis(pyridin-2-ylmethyl) benzoimidazolylidene) with cuprous oxide in acetonitrile readily yielded trinuclear complexes [Cu3(L1)3(PF6) 3] (1) and [Cu3(L2)3(PF6) 3] (2). Treatment of 1 with Ni(PPh3)2Cl 2 and Pd(cod)Cl2 gave [Ni(L1)Cl](PF6) (3) and [Pd(L1)Cl](PF6) (4), respectively, due to transmetalation. [Ni(L1)2](PF6)2 (5) was obtained from the reaction of [Cu3(L1)3(PF6)3] and Raney nickel in acetonitrile. All these complexes have been fully characterized. Both 1 and 2 consist of a triangular Cu3 core with each Cu-Cu bond capped by an imidazolylidene group. Each imidazolylidene acts as a bridging ligand in a μ2 mode and is bonded equally to two Cu(I) ions. The pincer nickel and palladium complexes are square-planar and contain a tridentate NCN ligand. Complexes 3 and 4 are efficient catalyst precursors for Kumada-Corriu and Suzuki-Miyaura coupling reactions of aryl halides with organometallic reagents.
