4783-68-0Relevant academic research and scientific papers
A CONVENIENT METHOD FOR THE PREPARATION OF 6-PHENOXY-2-PYRIDINECARBALDEHYDE
Ozawa, Kiyomi,Ishii, Shigeru,Hatanaka, Masataka
, p. 1803 - 1804 (1985)
6-Phenoxy-2-pyridinecarbaldehyde was prepared in good yields through a few reaction steps utilizing Grignard reaction which has been regarded disadvantageous for preparation of pyridinecarbaldehydes.
Study on selectivity in the reaction of 2-substituted pyridinium-N-imines with dimethyl acetylenedicarboxylate
Supranovich, Vyacheslav I.,Vorob'ev, Aleksey Yu.,Borodkin, Gennady I.,Gatilov, Yury V.,Shubin, Vyacheslav G.
, p. 1093 - 1096 (2016)
Reactions of 2-X-pyridinium-N-imines (X = F, Cl, Br, CN, OPh, NH2, N-morpholine) with dimethyl acetylenedicarboxylate (DMAD) have been studied. In the case of X = Cl, Br, CN, OPh both 7-substituted- and 7-H-pyrazolo[1,5-a]pyridines are formed. The 7-H/7-X ratio usually increases with the growing solvent polarity. The reaction of N-amino-2-iminopyridine with DMAD gives substituted pyrido[1,2-b][1,2,4]triazine.
Ligand compound for copper catalyzed aryl halide coupling reaction, catalytic system and coupling reaction
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Paragraph 0134-0138; 0141, (2021/05/29)
The invention provides a ligand compound capable of being used for copper catalyzed aryl halide coupling reaction, the ligand compound is a three-class compound containing a 2-(substituted or non-substituted) aminopyridine nitrogen-oxygen group, and the invention also provides a catalytic system for the aryl halide coupling reaction. Thecatalytic system comprises a copper catalyst, a compound containing a 2-(substituted or non-substituted) aminopyridine nitrogen-oxygen group adopted as a ligand, alkali and a solvent, and meanwhile, the invention also provides a system for the aryl halide coupling reaction adopting the catalyst system. The compound containing the 2-(substituted or non-substituted) aminopyridine nitrogen oxygen group can be used as the ligand for the copper catalyzed aryl chloride coupling reaction, and the ligand is stable under a strong alkaline condition and can well maintain catalytic activity when being used for the copper-catalyzed aryl chloride coupling reaction. In addition, the copper catalyst adopting the compound as the ligand can particularly effectively promote coupling of copper catalyzed aryl chloride and various nucleophilic reagents which are difficult to generate under conventional conditions, C-N, C-O and C-S bonds are generated, and numerous useful small molecule compounds are synthesized. Therefore, the aryl halide coupling reaction has a very good large-scale application prospect by adopting the copper catalysis system of the ligand.
Remarkably Efficient Iridium Catalysts for Directed C(sp2)-H and C(sp3)-H Borylation of Diverse Classes of Substrates
Chattopadhyay, Buddhadeb,Hassan, Mirja Md Mahamudul,Hoque, Md Emdadul
supporting information, p. 5022 - 5037 (2021/05/04)
Here we describe the discovery of a new class of C-H borylation catalysts and their use for regioselective C-H borylation of aromatic, heteroaromatic, and aliphatic systems. The new catalysts have Ir-C(thienyl) or Ir-C(furyl) anionic ligands instead of the diamine-type neutral chelating ligands used in the standard C-H borylation conditions. It is reported that the employment of these newly discovered catalysts show excellent reactivity and ortho-selectivity for diverse classes of aromatic substrates with high isolated yields. Moreover, the catalysts proved to be efficient for a wide number of aliphatic substrates for selective C(sp3)-H bond borylations. Heterocyclic molecules are selectively borylated using the inherently elevated reactivity of the C-H bonds. A number of late-stage C-H functionalization have been described using the same catalysts. Furthermore, we show that one of the catalysts could be used even in open air for the C(sp2)-H and C(sp3)-H borylations enabling the method more general. Preliminary mechanistic studies suggest that the active catalytic intermediate is the Ir(bis)boryl complex, and the attached ligand acts as bidentate ligand. Collectively, this study underlines the discovery of new class of C-H borylation catalysts that should find wide application in the context of C-H functionalization chemistry.
Solvent selection scheme using machine learning based on physicochemical description of solvent molecules: Application to cyclic organometallic reaction
Fujinami, Mikito,Isshiki, Ryota,Maekawara, Hiroki,Nakai, Hiromi,Seino, Junji,Yamaguchi, Junichiro
supporting information, p. 841 - 845 (2020/08/28)
A solvent selection scheme for optimization of reactions is proposed using machine learning, based on the numerical descriptions of solvent molecules. Twenty-eight key solvents were represented using 17 physicochemical descriptors. Clustering analysis results implied that the descriptor represents the chemical characteristics of the solvent molecules. During the assessment of an organometallic reaction system, the regression analysis indicated that learning even a small number of experimental results can be useful for identifying solvents that will produce high experimental yields. Observation of the regression coefficients, and both clustering and regression analysis, can be effective when selecting a solvent to be used for an experiment.
Ruthenium-Catalyzed meta-CAr–H Bond Difluoroalkylation of 2-Phenoxypyridines
Jia, Chunqi,Wang, Shichong,Lv, Xulu,Li, Gang,Zhong, Lei,Zou, Lei,Cui, Xiuling
supporting information, p. 1992 - 1995 (2020/03/23)
A ruthenium-catalyzed meta-selective CAr–H bond difluoroalkylation of 2-phenoxypyridine using 2-bromo-2,2-difluoroacetate has been developed. Mechanistic studies indicated that this difluoroalkylation might involve a radical process. Furthermore, a new method is reported for the synthesis of 2-(meta-difluoroalkylphenoxy)pyridine derivatives, which are present in many pharmaceuticals and other functional compounds.
A directing group-assisted ruthenium-catalyzed approach to access: Meta -nitrated phenols
Sasmal, Sheuli,Sinha, Soumya Kumar,Lahiri, Goutam Kumar,Maiti, Debabrata
supporting information, p. 7100 - 7103 (2020/07/14)
meta-Selective C-H nitration of phenol derivatives was developed using a Ru-catalyzed σ-activation strategy. Cu(NO3)2·3H2O was employed as the nitrating source, whereas Ru3(CO)12 was found to be the most suitable metal catalyst for the protocol. Mechanistic studies suggested involvement of an ortho-CAr-H metal intermediate, which promoted meta-electrophilic aromatic substitution and silver-assisted free-radical pathway.
N - And O -arylation of pyridin-2-ones with diaryliodonium salts: Base-dependent orthogonal selectivity under metal-free conditions
Abe, Yusuke,Hanazawa, Natsumi,Katagiri, Kotone,Kuriyama, Masami,Ono, Shimpei,Onomura, Osamu,Yamamoto, Kosuke
, p. 8295 - 8300 (2020/09/09)
Metal-free N- and O-arylation reactions of pyridin-2-ones as ambident nucleophiles have been achieved with diaryliodonium salts on the basis of base-dependent chemoselectivity. In the presence of N,N-diethylaniline in fluorobenzene, pyridin-2-ones were very selectively converted to N-arylated products in high yields. On the other hand, the O-arylation reactions smoothly proceeded with the use of quinoline in chlorobenzene, leading to high yields and selectivities. In these methods, a variety of pyridin-2-ones in addition to pyridin-4-one and a set of diaryliodonium salts were accepted as suitable reaction partners.
Transition-Metal-Catalyzed Transformation of Sulfonates via S-O Bond Cleavage: Synthesis of Alkyl Aryl Ether and Diaryl Ether
Chen, Xuemeng,Xiao, Xue,Sun, Haotian,Li, Yue,Cao, Haolin,Zhang, Xuemei,Yang, Shengyong,Lian, Zhong
supporting information, p. 8879 - 8883 (2019/11/14)
The catalytic conversion of sulfonates, a versatile class of pharmaceutical intermediates, is usually based on C-O bond cleavage. In this paper, however, we discover a rare transformation of sulfonates via S-O bond cleavage catalyzed by transition metal, through which alkyl sulfonates could undergo an intramolecular desulfitative C-O coupling to form aryl alkyl ethers in the presence of a nickel catalyst. Meanwhile, aryl sulfonates perform similarly to give diaryl ethers catalyzed by a palladium complex. This transformation could tolerate a wide range of functionalities. Controlled experiments reveal that the 2-pyridyl group is necessary to promote the reaction as designed. Crossover experiments proved that this transformation might proceed partly in an intermolecular pathway.
Substituent Effects of 2-Pyridones on Selective O-Arylation with Diaryliodonium Salts: Synthesis of 2-Aryloxypyridines under Transition-Metal-Free Conditions
Li, Xiao-Hua,Ye, Ai-Hui,Liang, Cui,Mo, Dong-Liang
, p. 1699 - 1710 (2018/02/06)
An efficient transition-metal-free strategy to synthesize 2-aryloxypyridine derivatives has been developed by a selective O-arylation of 2-pyridones with diaryliodonium salts. The reaction was compatible with a series of functional groups for 2-pyridones and diaryliodonium salts such as halides, nitro, cyano, and ester groups. The substituents at the C6-position of 2-pyridones favored O-arylation products because of steric hindrance. The reaction was easily performed on a gram-scale and 6-chloro-2-pyridone was a good precursor to access various unsubstituted 2-aryloxypyridines by dehalogenation. A P2Y 1 lead compound analogue could be prepared in good yield over two steps.
