612-94-2Relevant academic research and scientific papers
Synthesis and catalytic activity in suzuki coupling of nickel complexes bearing n -butyl- and triethoxysilylpropyl-substituted NHC ligands: Toward the heterogenization of molecular catalysts
Oertel, Anna Magdalena,Ritleng, Vincent,Chetcuti, Michael J.
, p. 2829 - 2840 (2012)
Cyclopentadienyl N-heterocyclic carbene (NHC) nickel complexes of general formula [Ni(R-NHC-nBu)XCp] [R-NHC-nBu = 1-butyl-3-methyl-, 1-isopropyl-3-butyl-, 1-phenyl-3-butyl-, 1-(2,4,6-trimethylphenyl)-3-butyl-, 1-(2,6- diisopropylphenyl)-3-butyl-imidazol-2-ylidene; X = Cl or I; Cp = η5-C5H5], which bear an n-butyl side-chain attached to one of the nitrogen atoms of the NHC ring, were synthesized as models for trialkoxysilylpropyl-substituted complexes. They were prepared by the direct reactions of nickelocene with the corresponding imidazolium salts (R-NHC-nBuHX). The new complexes [Ni(Me-NHC-nBu)ClCp] (1a), [Ni(iPr-NHC-nBu)ClCp] (1b), [Ni(Ph-NHC-nBu)ICp] (1c), [Ni(Mes-NHC-nBu)ICp] (1d), and [Ni(iPr2Ph-NHC-nBu)ICp] (1e) were obtained in moderate to good yields and were fully characterized by standard spectroscopic techniques, and in the cases of 1a,b,d,e by single-crystal X-ray crystallography. The bulky electron-rich pentamethylcyclopentadienyl derivatives, [Ni(Mes-NHC-nBu) ICp*] (2d) and [Ni(iPr2Ph-NHC-nBu)ICp*] (2e) (Cp* = η5-C5Me5), were prepared from reactions of in situ prepared [Ni(acac)Cp*] with the corresponding carbene precursors. Both Cp* complexes were also fully characterized spectroscopically, and their structures were established by single-crystal X-ray crystallography. All new complexes catalyzed the Suzuki-Miyaura cross-coupling of phenylboronic acid with aryl halides in the absence of cocatalysts or reductants. However, the small dialkyl-substituted species 1a and 1b proved to be the least efficient. In addition, in contrast to our previous results with the closely related diaryl-substituted species [Ni(Ar2NHC)LCp?] (L = Cl-, NCMe (PF6-); Cp? = Cp, Cp*), in which complexes that bear the electron-rich Cp* ligand were much more active than those bearing the Cp ligand, no substantial catalytic behavior differences were observed between the Cp complexes 1d,e and their Cp* counterparts 2d,e. A TOF of up to 352 h-1, a so far unprecedented rate for nickel(II) complexes under similar conditions, was even observed with the Cp complex 1d. In view of these encouraging results, the triethoxysilylpropyl-substituted analogue of 1d, [Ni(Mes-NHC-TES)ClCp] (1d-TES) (Mes-NHC-TES = 1-(2,4,6-trimethylphenyl)-3-[3-(triethoxysilyl)propyl]imidazol-2- ylidene), was prepared, fully characterized, and tested catalytically. As it showed similar catalytic activity to 1d, it was heterogenized on alumina to give 1d-Al. The latter species, however, exhibited a greatly reduced catalytic activity compared to 1d and 1d-TES. Possible reasons for both the excellent activities of 1d and 1d-TES and the disappointing activity of 1d-Al are discussed.
Covalently stabilized Pd clusters in microporous polyphenylene: An efficient catalyst for Suzuki reactions under aerobic conditions
Song, Qi,Jia, Yuying,Luo, Bin,He, Haiyong,Zhi, Linjie
, p. 2460 - 2465 (2013)
A novel catalyst composed of a microporous polyphenylene network and covalently stabilized Pd clusters (Pd/MPP) for highly efficient Suzuki-Miyaura coupling is synthesized with an in-situ one-pot chemical approach, through the catalytic trimerization of 1,3,5-triethynylbenzene. The unique Pd/MPP cluster exhibits very high catalytic activity for a broad scope of Suzuki-Miyaura reactions with short reaction time, good yield, and high turnover number and turnover frequency values, even in aqueous media under aerobic conditions. The strong covalent interaction between Pd and MPP network prevents the agglomeration or leaching of Pd clusters and enables the catalyst to remain highly active, even after a number of cycles. Copyright
Porphyrenediynes: synthesis and cyclization of meso-enediynylporphyrins
Spence, John D.,Hargrove, Amanda E.,Crampton, Hannah L.,Thomas, David W.
, p. 725 - 728 (2007)
Synthetic methodology to prepare porphyrinylethynyl enediynes has been developed. Compared to phenylethynyl derivatives, a bulky porphyrinic substituent on the alkyne significantly increases the thermal barrier toward Bergman cyclization and leads to multiple photolysis products.
Construction of covalent organic framework for catalysis: Pd/COF-LZU1 in Suzuki-Miyaura coupling reaction
Ding, San-Yuan,Gao, Jia,Wang, Qiong,Zhang, Yuan,Song, Wei-Guo,Su, Cheng-Yong,Wang, Wei
, p. 19816 - 19822 (2011)
Covalent organic frameworks (COFs) are crystalline porous solids with well-defined two- or three-dimensional molecular structures. Although the structural regularity provides this new type of porous material with high potentials in catalysis, no example has been presented so far. Herein, we report the first application of a new COF material, COF-LZU1, for highly efficient catalysis. The easily prepared imine-linked COF-LZU1 possesses a two-dimensional eclipsed layered-sheet structure, making its incorporation with metal ions feasible. Via a simple post-treatment, a Pd(II)-containing COF, Pd/COF-LZU1, was accordingly synthesized, which showed excellent catalytic activity in catalyzing the Suzuki-Miyaura coupling reaction. The superior utility of Pd/COF-LZU1 in catalysis was elucidated by the broad scope of the reactants and the excellent yields (96-98%) of the reaction products, together with the high stability and easy recyclability of the catalyst. We expect that our approach will further boost research on designing and employing functional COF materials for catalysis.
'Awaken' aryl sulfonyl fluoride: a new partner in the Suzuki-Miyaura coupling reaction
Ding, Chengrong,Guan, Chenfei,Miao, Huihui,Zhang, Guofu,Zhao, Yiyong
supporting information, p. 3560 - 3564 (2022/03/07)
An example of the activation of the -SO2F group, which is traditionally considered a stable group even in the presence of a transition metal, is described using a novel partner in the Suzuki-Miyaura coupling reaction catalyzed by Pd(OAc)2 and Ruphos as ligands. The products showed good to outstanding yields and broad functional group compatibility under optimal conditions. The sequential synthesis of non-symmetric terphenyls and the gram grade process highlight the approach's synthetic utility. DFT calculations have shown that Pd0 prefers to insert between C-S bonds rather than S-F bonds. This journal is
Nickel-Catalyzed Direct Cross-Coupling of Aryl Sulfonium Salt with Aryl Bromide
Ma, Na-Na,Ren, Jing-Ao,Liu, Xiang,Chu, Xue-Qiang,Rao, Weidong,Shen, Zhi-Liang
supporting information, p. 1953 - 1957 (2022/03/27)
The direct cross-couplings of aryl sulfonium salts with aryl halides could be achieved by using nickel as a reaction catalyst. The reactions proceeded efficiently via C-S bond activation in the presence of magnesium turnings and lithium chloride in THF at ambient temperature to afford the corresponding biaryls in moderate to good yields, potentially serving as an attractive alternative to conventional cross-coupling reactions employing preprepared organometallic reagents.
Arylketones as Aryl Donors in Palladium-Catalyzed Suzuki-Miyaura Couplings
Wang, Zhen-Yu,Ma, Biao,Xu, Hui,Wang, Xing,Zhang, Xu,Dai, Hui-Xiong
, p. 8291 - 8295 (2021/11/13)
Herein, we report the arylation, alkylation, and alkenylation of aryl ketones via a palladium-catalyzed Suzuki-Miyaura cross-coupling reaction. The use of the pyridine-oxazoline ligand is the key to the cleavage of the unstrained C-C bond. The late-stage arylation of aryl ketones derived from drugs and natural products demonstrated the synthetic utility of this protocol.
Selective synthesis of 1-halonaphthalenes by copper-catalyzed benzannulation
Umeda, Rui,Ueda, Ryo,Tanaka, Taiki,Hayashi, Akitsugu,Ikeshita, Masahiro,Suzuki, Shuichi,Naota, Takeshi,Nishiyama, Yutaka
supporting information, (2020/12/29)
The synthesis of 1-halonaphthalenes by the Cu-catalyzed benzannulation reaction of 2-(phenylethynyl)benzaldehyde and alkynes in the presence of the halogen reagents such as NBS, NCS, and NIS, was developed. This protocol afforded various type of 1-halonap
Nickel(II) complexes with N,O-donor thiopseudourea ligands: Syntheses, structures, and catalytic applications in Kumada–Corriu cross-coupling reactions
Shakunthala, Kinche,Srivastava, Ankit Kumar,Babu, G. Narendra,Keesara, Srinivas,Pal, Samudranil
, (2021/04/19)
Synthesis, characterization, and physical properties of benzyl-N′-(4-R-benzoyl)-N-(2,6-diisopropylphenyl)carbamimidothioates, HL1 (R = H) and HL2 (R = Cl), and their nickel(II) complexes having the general molecular formula [Ni(L1/2)2] (1 and 2) have been reported. Elemental analysis, magnetic susceptibility, solution electrical conductivity, and various spectroscopic (IR, UV–Vis, and 1H NMR) measurements were used to characterize HL1, HL2, and the two complexes (1 and 2). The molecular structures of all four compounds were determined by single-crystal X-ray crystallographic studies. The structures of HL1 and HL2 showed the imino-ketone form of both compounds. In each of 1 and 2, the six-membered chelate ring forming iminolate-O and azomethine-N donor two (L1/2)? ligands form a square-planar trans-N2O2 coordination environment around the metal center. The spectroscopic characteristics of HL1, HL2, 1, and 2 are consistent with their molecular structures. Both complexes were successfully employed as efficient catalysts in Kumada–Corriu C-C cross-coupling reactions of aryl bromides with phenylmagnesium bromide. The reactions provided biaryl products in good to excellent yields with a good substrate scope.
Tris-NHC-propagated self-supported polymer-based Pd catalysts for heterogeneous C-H functionalization
Choudhury, Joyanta,Dutta, Tapas Kumar,Mandal, Tanmoy,Mohanty, Sunit
supporting information, p. 10182 - 10185 (2021/10/12)
Three-dimensionally propagated imidazolium-containing mesoporous coordination polymer and organic polymer-based platforms were successfully exploited to develop single-site heterogenized Pd-NHC catalysts for oxidative arene/heteroarene C-H functionalization reactions. The catalysts were efficient in directed arene halogenation, and nondirected arene and heteroarene arylation reactions. High catalytic activity, excellent heterogeneity and recyclability were offered by these systems making them promising candidates in the area of heterogeneous C-H functionalization, where efficient catalysts are still scarce.
