4373-58-4Relevant academic research and scientific papers
New aspects of the aromatic photosubstitution with iodopyridines
Ohkura,Terashima,Kanaoka,Seki
, p. 1920 - 1924 (1993)
Reactive entities in the photoreaction of 2-, 3- and 4-iodopyridines with substituted benzenes were investigated; 3- and 4-pyridylation could be explained in terms of radical reaction, while the 2-pyridyl cation was an important intermediate in the 2-pyridylation. The importance of the unshared electron pair of the nitrogen adjacent to the radical carbon for the conversion of the 2-pyridyl radical initially produced into the cation is discussed on the basis of molecular orbital (MO) calculations.
Cp*Rh(iii)/boron hybrid catalysis for directed C-H addition to β-substituted α,β-unsaturated carboxylic acids
Hirata, Yuki,Kojima, Masahiro,Matsunaga, Shigeki,Tanaka, Ryo,Yoshino, Tatsuhiko
supporting information, p. 76 - 79 (2021/12/29)
The C-H bond addition reaction of 2-phenylpyridine derivatives with α,β-unsaturated carboxylic acids catalyzed by Cp*Rh(iii)/BH3·SMe2is reported. Activation of C-H bonds with the rhodium catalyst and activation of α,β-unsaturated carboxylic acids with the boron catalyst cooperatively work, and a BINOL-urea hybrid ligand significantly improved the reactivity. With the optimized hybrid catalytic system, various β-disubstituted carboxylic acids were obtained under mild reaction conditions.
Access to Branched Allylarenes via Rhodium(III)-Catalyzed C-H Allylation of (Hetero)arenes with 2-Methylidenetrimethylene Carbonate
Zhang, Shang-Shi,Zheng, Yi-Chuan,Zhang, Zi-Wu,Chen, Shao-Yong,Xie, Hui,Shu, Bing,Song, Jia-Lin,Liu, Yan-Zhi,Zeng, Yao-Fu,Zhang, Luyong
supporting information, p. 5719 - 5723 (2021/08/16)
A rhodium(III)-catalyzed C-H allylation of (hetero)arenes by using 2-methylidenetrimethylene carbonate as an efficient allylic source has been developed for the first time. Five different directing groups including oxime, N-nitroso, purine, pyridine, and pyrimidine were compatible, delivering various branched allylarenes bearing an allylic hydroxyl group in moderate to excellent yields.
Chromium-Catalyzed Reductive Cleavage of Unactivated Aromatic and Benzylic C-O Bonds
Yuan, Shuqing,Ling, Liang,Tang, Jinghua,Luo, Meiming,Zeng, Xiaoming
, 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.
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.
BLUE AND NARROW BAND GREEN AND RED EMITTING METAL COMPLEXES
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Paragraph 0082; 0084, (2019/09/20)
The present invention includes tetradentate platinum (II) complexes for narrow band green and red phosphorescent emitters. The present invention also includes blue emitting metal complexes with six-membered chelate rings based on fused carbazole. The pres
SPIRO-CONTAINING PLATINUM (II) EMITTERS WITH TUNABLE EMISSION ENERGIES AND SYNTHESES THEREOF
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Page/Page column 18, (2019/08/12)
An asymmetric tetradentate metal complex of a N^C^C^N comprising tetradentate ligand has a metal connected to binding sites which are connected to each other via three or four covalent bonds that can be either single or double bonds with bridging linkers reside between C^C and C^N moieties. These linkers result in three-dimension metal complexes with distorted square planar geometries. The four donor atoms coordinate to a metal center. Upon metal binding a 5-6-6 membered metallocycle is formed upon chelation including a first nitrogen donor bond, a first metal-carbon bond, a second metal-carbon bond, and a second nitrogen donor bond. The light emission from these metal complexes can be tuned by the ligand structure over the entire visible spectrum.
Ruthenium-Catalyzed ortho- And meta-H/D Exchange of Arenes
Zhao, Liang-Liang,Liu, Wei,Zhang, Zengyu,Zhao, Hongyan,Wang, Qi,Yan, Xiaoyu
supporting information, p. 10023 - 10027 (2019/12/24)
Ruthenium-catalyzed aromatic H/D exchange in [D4]acetic acid has been developed. By using N-heteroarenes as directing groups, both ortho and meta positions are selectively deuterated with high levels of D incorporation. Moreover, this strategy provides an alternative way to achieve meta-C-H activation.
Multicomponent Aromatic and Benzylic Mannich Reactions through C?H Bond Activation
Xavier, Tania,Rayapin, Corinne,Le Gall, Erwan,Presset, Marc
supporting information, p. 13824 - 13828 (2019/11/03)
Multicomponent Mannich reactions through C?H bond activation are described. These transformations allowed for the straightforward generation of densely substituted benzylic and homo-benzylic amines in good yields. The reaction involves a reaction between two transient species: an organometallic species, generated by transition-metal-catalyzed sp2 or sp3 C?H bond activation and an in situ generated imine. The use of an acetal as an aldehyde surrogate was found essential for the reaction to proceed. The process could be successfully applied to RhIII-catalyzed sp2 C?H bond functionalization and extended to CuII-catalyzed sp3 C?H bond functionalization.
Dibenzofuran and dibenzothiophene based palladium(ii)/NHC catalysts-synthesis and applications in C-C bond formation
Karthik, Shanmugam,Gandhi, Thirumanavelan
supporting information, p. 15811 - 15819 (2018/10/04)
In the quest for a new ligand system for Pd(ii)/NHCs, we developed new dibenzofuran and dibenzothiophene based palladium N-heterocyclic carbene catalysts D1-D6 in good yields. All the catalysts were characterized by multinuclear NMR spectroscopy and HRMS. The X-ray crystal structure of the representative dibenzothiophene based Pd(ii)/NHC D4 was determined. Among the precatalysts, D1 was shown to be highly effective in the Suzuki-Miyaura cross-coupling reaction of heterocyclic bromides with boronic acids. Besides, D1 affords diverse arylated benzoxazoles via direct C-H bond functionalization with substituted bromo derivatives.
