5957-89-1Relevant academic research and scientific papers
Selective C-O Bond Reduction and Borylation of Aryl Ethers Catalyzed by a Rhodium-Aluminum Heterobimetallic Complex
Hara, Naofumi,Nakao, Yoshiaki,Saito, Teruhiko,Seki, Rin
, p. 6388 - 6394 (2021/05/31)
We report the catalytic reduction of a C-O bond and the borylation by a rhodium complex bearing an X-Type PAlP pincer ligand. We have revealed the reaction mechanism based on the characterization of the reaction intermediate and deuterium-labeling experiments. Notably, this novel catalytic system shows steric-hindrance-dependent chemoselectivity that is distinct from conventional Ni-based catalysts and suggests a new strategy for selective C-O bond activation by heterobimetallic catalysis.
Chromium-Catalyzed Reductive Cleavage of Unactivated Aromatic and Benzylic C-O Bonds
Yuan, Shuqing,Ling, Liang,Tang, Jinghua,Luo, Meiming,Zeng, Xiaoming
supporting information, p. 3343 - 3350 (2021/07/02)
Reductive cleavage of aromatic and benzylic C-O bonds by chromium catalysis is reported. This deoxygenative reaction was promoted by low-cost CrCl 2precatalyst combined with poly(methyl hydrogen siloxane) as the mild reducing agent, providing a strategy in forming reduced motifs by cleavage of unactivated C-O bonds. A range of functional groups such as bromide, chloride, fluoride, hydroxyl, amino, and alkoxycarbonyl can be retained in the reduction.
Directing Group-Promoted Inert C?O Bond Activation Using Versatile Boronic Acid as a Coupling Agent
Ambre, Ram,Wang, Ting-Hsuan,Xian, Anmei,Chen, Yu-Shiuan,Liang, Yu-Fu,Jurca, Titel,Zhao, Lili,Ong, Tiow-Gan
supporting information, p. 17021 - 17026 (2020/11/30)
A simple Ni(cod)2 and carbene mediated strategy facilitates the efficient catalytic cross-coupling of methoxyarenes with a variety of organoboron reagents. Directing groups facilitate the activation of inert C?O bonds in under-utilized aryl methyl ethers enabling their adaptation for C?C cross-coupling reactions as less toxic surrogates to the ubiquitous haloarenes. The method reported enables C?C cross-coupling with readily available and economical arylboronic acid reagents, which is unprecedented, and compares well with other organoboron reagents with similarly high reactivity. Extension to directing group assisted chemo-selective C?O bond cleavage, and further application towards the synthesis of novel bifunctionalized biaryls is reported. Key to the success of this protocol is the use of directing groups proximal to the reaction center to facilitate the activation of the inert C?OMe bond.
Palladium (II) Complexes Containing 2-Phenylpyridine Derivatives: Synthesis, Molecular Structures, and Catalytic Activity for Suzuki–Miyaura Cross-Coupling Reactions
Adamson, A.,Alhaddad, M. R.,Arshad, M. N.,Asiri, A. M.,Budiman, Y. P.,Mkhalid, I.,Muhammad, R.
, p. 466 - 475 (2020/07/31)
The preparation and characterization of a series of new 2-phenylpyridine derivative ligands consisting of 2-(R) pyridine (R = mesityl (L1), 2,6-dimethylphenyl (L2), o-tolyl (L3), m-tolyl (L4), p-tolyl (L5), o-methoxyphenyl (L6), and p-methoxyphenyl (L7)) and their Pd complexes [PdCl2L2] (L1–L7) is investigated using a combination of X-ray diffraction spectroscopy, GC-MS, and NMR. The crystal structures show that the Pd complexes adopt a square planar geometry, and the monodentate ligand is coordinated through the N donor of the pyridine ring to the Pd atom. The catalytic activities of the synthesized complexes are investigated. The square planar Pd complex trans-[(2-mesitylpy)2PdCl2)] shows a high efficiency in promoting Suzuki-Miyaura cross coupling in an aqueous solvent under aerobic conditions.
Photoarylation of Pyridines Using Aryldiazonium Salts and Visible Light: An EDA Approach
Bartolomeu, Aloisio De A.,Brocksom, Timothy J.,De Oliveira, Kleber T.,No?l, Timothy,Silva, Rodrigo C.
, (2019/08/26)
A metal-free methodology for the photoarylation of pyridines, in water, is described giving 2 and 4-arylated-pyridines in yields up to 96percent. The scope of the aryldiazonium salts is presented showing important results depending on the nature and position of the substituent group in the diazonium salt, that is, electron-donating or electron-withdrawing in the ortho, meta, or para positions. Further heteroaromatics were also successfully photoarylated. Mechanistic studies and comparison between our methodology and similar metal-catalyzed procedures are presented, suggesting the occurrence of a visible-light EDA complex which generates the aryl radical with no need for an additional photocatalyst.
Palladium-Catalyzed Electrochemical C-H Alkylation of Arenes
Yang, Qi-Liang,Li, Chuan-Zeng,Zhang, Liang-Wei,Li, Yu-Yan,Tong, Xiaofeng,Wu, Xin-Yan,Mei, Tian-Sheng
supporting information, p. 1208 - 1212 (2018/10/20)
Palladium-catalyzed electrochemical C-H functionalization reactions have emerged as attractive tools for organic synthesis. This process offers an alternative to conventional methods that require harsh chemical oxidants. However, this electrolysis requires divided cells to avoid catalyst deactivation by cathodic reduction. Herein, we report the first example of palladium-catalyzed electrochemical C-H alkylation of arenes using undivided electrochemical cells in water, thereby providing a practical solution for the introduction of alkyl groups into arenes.
A tetranuclear CuII2DyIII2 coordination cluster as a Suzuki (C-C) coupling reaction promoter
Kumar, Prashant,Griffiths, Kieran,Anson, Christopher E.,Powell, Annie K.,Kostakis, George E.
supporting information, p. 17202 - 17205 (2019/01/03)
The air-stable tetranuclear coordination cluster [CuII2DyIII2L4(NO3)2(CH3CN)2]·2(CH3CN), which can be obtained in high yield, promotes the Suzuki coupling reaction of phenylboronic acid with substituted aryl halides under environmentally benign conditions.
Enantioselective Synthesis of α-(Hetero)aryl Piperidines through Asymmetric Hydrogenation of Pyridinium Salts and Its Mechanistic Insights
Qu, Bo,Mangunuru, Hari P. R.,Tcyrulnikov, Sergei,Rivalti, Daniel,Zatolochnaya, Olga V.,Kurouski, Dmitry,Radomkit, Suttipol,Biswas, Soumik,Karyakarte, Shuklendu,Fandrick, Keith R.,Sieber, Joshua D.,Rodriguez, Sonia,Desrosiers, Jean-Nicolas,Haddad, Nizar,McKellop, Keith,Pennino, Scott,Lee, Heewon,Yee, Nathan K.,Song, Jinhua J.,Kozlowski, Marisa C.,Senanayake, Chris H.
supporting information, p. 1333 - 1337 (2018/03/09)
Enantioselective synthesis of α-aryl and α-heteroaryl piperidines is reported. The key step is an iridium-catalyzed asymmetric hydrogenation of substituted N-benzylpyridinium salts. High levels of enantioselectivity up to 99.3:0.7 er were obtained for a range of α-heteroaryl piperidines. DFT calculations support an outersphere dissociative mechanism for the pyridinium reduction. Notably, initial protonation of the final enamine intermediate determines the stereochemical outcome of the transformation rather than hydride reduction of the resultant iminium intermediate.
Direct ortho Arylation of Anisoles via the Formation of Four-Membered Lithiumcycles/Palladacycles
Xiong, Xiaoyu,Zhu, Ranran,Huang, Lin,Chang, Shuqin,Huang, Jianhui
supporting information, p. 2046 - 2050 (2017/09/13)
We report here our latest discovery on the directed lithiation and palladium-catalyzed arylation of anisoles. During this research, the formation of a four-membered lithiumcycle followed by transmetalation to the corresponding palladacycle has been achieved, which is difficult to be obtained from palladium-catalyzed C-H activation processes. This approach has provided an alternative way of introducing functionalities to arenes such as anisoles, thioanisoles, and anilines. This approach also features an excellent monoselectivity compared with reactions under transition-metal-catalyzed conditions.
An active catalytic system for Suzuki-Miyaura cross-coupling reactions using low levels of palladium loading
Yan, Meng-Qi,Yuan, Jia,Lan, Fang,Zeng, Si-Hao,Gao, Meng-Yue,Liu, Sheng-Hua,Chen, Jian,Yu, Guang-Ao
supporting information, p. 3924 - 3929 (2017/07/10)
An easily available Pd(OAc)2/(2-(anthracen-9-yl)-1H-inden-3-yl) dicyclohexylphosphine/toluene/iPrOH/water catalytic system was developed, which shows high catalytic activity in the Suzuki-Miyaura cross-coupling reactions of a diverse array of aryl and heteroaryl chlorides with Pd loadings down to 0.01 mol%.
