Pyridine-derivatives

Formula: C5H5BrN2On October 4, 2019 ,《Silver-Mediated Trifluoromethoxylation of (Hetero)aryldiazonium Tetrafluoroborates》 was published in Organic Letters. The article was written by Yang, Yu-Ming; Yao, Jian-Fei; Yan, Wei; Luo, Zhuangzhu; Tang, Zhen-Yu. The article contains the following contents:

Here we report a silver-mediated trifluoromethoxylation of (hetero)aryldiazonium tetrafluoroborates by converting an aromatic amino group into an OCF3 group. This method, which can be considered to be a trifluoromethoxylation variation of the classic Sandmeyer-type reaction, uses readily available aryl and heteroaromatic amines as starting materials and AgOCF3 as trifluoromethoxylating reagents. The broad substrate scope and simple, mild reaction condition made this transformation a valuable method in constructing aryl-OCF3 bonds. In addition to this study using 2-Bromopyridin-3-amine, there are many other studies that have used 2-Bromopyridin-3-amine(cas: 39856-58-1Formula: C5H5BrN2) was used in this study.

2-Bromopyridin-3-amine(cas: 39856-58-1) belongs to anime. Amine, any member of a family of nitrogen-containing organic compounds that is derived, either in principle or in practice, from ammonia (NH3). Naturally occurring amines include the alkaloids, which are present in certain plants; the catecholamine neurotransmitters (i.e., dopamine, epinephrine, and norepinephrine); and a local chemical mediator, histamine, that occurs in most animal tissues.Formula: C5H5BrN2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Quality Control of 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridineOn June 1, 2018, Li, Tian-Ren; Zhang, Mao-Mao; Wang, Bao-Cheng; Lu, Liang-Qiu; Xiao, Wen-Jing published an article in Organic Letters. The article was 《Synthesis of 3,3′-Biindoles through a Copper-Catalyzed Friedel-Crafts Propargylation/Hydroamination/Aromatization Sequence》. The article mentions the following:

A copper-catalyzed Friedel-Crafts propargylation/hydroamination/aromatization sequence is described. In the presence of a catalytic amount of CuI, this sequential reaction can convert ethynyl benzoxazinanones and indoles into a diverse set of 3,3′-biindoles with high efficiency and selectivity. Moreover, the synthesis of other indole-heteroaryl mols. and the catalytic asym. formation of axially chiral 3,3′-biindoles are demonstrated. In the experimental materials used by the author, we found 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine(cas: 410092-98-7Quality Control of 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine)

2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridine(cas: 410092-98-7) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. Quality Control of 2,6-Bis((4S,5S)-4,5-diphenyl-4,5-dihydrooxazol-2-yl)pyridineThe lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Liang, Ren-Xiao; Zhong, Chao; Liu, Zhi-Hong; Yang, Miao; Tang, Heng-Wei; Chen, Jian-Fei; Yang, Yun-Fang; Jia, Yi-Xia published an article on February 5 ,2021. The article was titled 《Enantioselective Arylation of Tetrasubstituted Enamines: Access to Enantioenriched Indolenine and 1H-Indole Derivatives》, and you may find the article in ACS Catalysis.Recommanded Product: 2-Bromopyridin-3-amine The information in the text is summarized as follows:

Palladium-catalyzed intramol. enantioselective β-arylation of tetrasubstituted endocyclic and exocyclic enamines was developed. A range of optically active medium-ring fused indolenines or 3,3′-spiroindolenines were achieved in enantiomeric ratios up to 98:2 with Cs2CO3 or K3PO4 as the base in the presence of chiral PHOX ligands. The use of Ag3PO4 as a base led to enantioenriched 1H-indoles in good enantiomeric ratios (up to 89:11) with (S)-DIFLUORPHOS as a chiral ligand, which proceeded via a possible domino enamine-isomerization/β-arylation sequence. The experimental part of the paper was very detailed, including the reaction process of 2-Bromopyridin-3-amine(cas: 39856-58-1Recommanded Product: 2-Bromopyridin-3-amine)

2-Bromopyridin-3-amine(cas: 39856-58-1) belongs to anime. Reaction with nitrous acid (HNO2), which functions as an acylating agent that is a source of the nitrosyl group (―NO), converts aliphatic primary amines to nitrogen and mixtures of alkenes and alcohols corresponding to the alkyl group in a complex process. This reaction has been used for analytical determination of primary amino groups in a procedure known as the Van Slyke method.Recommanded Product: 2-Bromopyridin-3-amine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

The author of 《A bifunctional small molecular photocatalyst with a redox center and a Lewis acid site for one-pot tandem oxidation-acetalization》 were Rao, Cai-Hui; Ma, Shuai; Cui, Jing-Wang; Jia, Meng-Ze; Yao, Xin-Rong; Zhang, Jie. And the article was published in Green Chemistry in 2022. Electric Literature of C20H14N4 The author mentioned the following in the article:

By combining the double identity of a redox center and a Lewis acid site of the pyridinium derivative, the first bifunctional small mol. photocatalyst was developed for the one-pot tandem oxidation-acetalization reaction. A mechanism study revealed that pyridinium-mediated electron transfer and the photoactivation of mol. oxygen greatly facilitate the transformation of benzyl alcs. into the corresponding aldehydes, while the Lewis acid site of this bifunctional photocatalyst promoted a highly efficient acetalization reaction without any significant loss in activity after multiple reaction cycles, thus achieving the direct conversion of various alcs. into either cyclic or acyclic acetals in good yields under mild conditions without any additives. After reading the article, we found that the author used 4′-(4-Pyridyl)-2,2′:6′,2”-terpyridine(cas: 112881-51-3Electric Literature of C20H14N4)

4′-(4-Pyridyl)-2,2′:6′,2”-terpyridine(cas: 112881-51-3) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. Electric Literature of C20H14N4 Pyridine has a conjugated system of six π electrons that are delocalized over the ring.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2015,Ryan, Sarah J.; Schimler, Sydonie D.; Bland, Douglas C.; Sanford, Melanie S. published 《Acyl Azolium Fluorides for Room Temperature Nucleophilic Aromatic Fluorination of Chloro- and Nitroarenes》.Organic Letters published the findings.COA of Formula: C5H3BrClN The information in the text is summarized as follows:

The reaction of acid fluorides with N-heterocyclic carbenes (NHCs) produces anhydrous acyl azolium fluorides. With appropriate selection of the acid fluoride and NHC, these salts can be used for the room temperature SNAr fluorination of a variety of aryl chlorides and nitroarenes. E.g., in presence of N-heterocyclic carbene (I) and 4-MeOC6H4COF, fluorination of aryl chloride (II) gave 99% aryl fluoride (III). In the experiment, the researchers used 5-Bromo-2-chloropyridine(cas: 53939-30-3COA of Formula: C5H3BrClN)

5-Bromo-2-chloropyridine(cas: 53939-30-3) belongs to pyridine. Pyridine is very deactivated towards electrophilic substitution with respect to benzene. For this reason classical formylation, using methods such as the Gattermann or Vilsmeier reactions, are not generally successful. COA of Formula: C5H3BrClN

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2016,Deutsch, Amrei; Jessen, Christoph; Deutsch, Carl; Karaghiosoff, Konstantin; Hoffmann-Roeder, Anja published 《One-Pot Synthesis of Substituted Trifluoromethylated 2,3-Dihydro-1H-imidazoles》.Organic Letters published the findings.Recommanded Product: 5-Bromo-2-chloropyridine The information in the text is summarized as follows:

An operationally simple one-pot reaction for the preparation of a novel class of racemic trifluoromethylated 2,3-dihydro-1H-imidazoles derived from electron-poor N,O-acetals and aryl Grignard reagents is described. In addition, access to highly functionalized 2-trifluoromethyl-2,3-dihydro-1H-imidazoles was accomplished by reaction of N-aryl hemiaminal ethers and N-aryl trifluoroethylamines in the presence of an excess of n-butyllithium. In the part of experimental materials, we found many familiar compounds, such as 5-Bromo-2-chloropyridine(cas: 53939-30-3Recommanded Product: 5-Bromo-2-chloropyridine)

5-Bromo-2-chloropyridine(cas: 53939-30-3) belongs to pyridine. Pyridines form stable salts with strong acids. Pyridine itself is often used to neutralize acid formed in a reaction and as a basic solvent. Recommanded Product: 5-Bromo-2-chloropyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2017,Duong, Hung A.; Wu, Wenqin; Teo, Yu-Yuan published 《Cobalt-Catalyzed Cross-Coupling Reactions of Arylboronic Esters and Aryl Halides》.Organometallics published the findings.Computed Properties of C5H3BrClN The information in the text is summarized as follows:

An efficient cobalt catalyst system for the Suzuki-Miyaura cross-coupling reaction of arylboronic esters and aryl halides has been identified. In the presence of cobalt(II)/terpyridine catalyst and potassium methoxide, a diverse array of (hetero)biaryls have been prepared in moderate to excellent yields. In the experimental materials used by the author, we found 5-Bromo-2-chloropyridine(cas: 53939-30-3Computed Properties of C5H3BrClN)

5-Bromo-2-chloropyridine(cas: 53939-30-3) belongs to pyridine. In industry and in the lab, pyridine is used as a reaction solvent, particularly when its basicity is useful, and as a starting material for synthesizing some herbicides, fungicides, and antiseptics.Computed Properties of C5H3BrClN

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2017,Tsupova, Svetlana; Cadu, Alban; Stuck, Fabian; Rominger, Frank; Rudolph, Matthias; Samec, Joseph S. M.; Hashmi, A. Stephen K. published 《Dual Gold(I)-catalyzed Cyclization of Dialkynyl Pyridinium Salts》.ChemCatChem published the findings.HPLC of Formula: 128071-75-0 The information in the text is summarized as follows:

Novel dialkynyl pyridines were synthesized and protected as alkyl salts for dual gold(I)-catalyzed cycloisomerization. Different alkyl groups and counter ions were screened for the salts, with benzyl and hexafluorophosphate providing the best results. The cyclization led to NMR yields of >95% being obtained for a number of substrates. Step-wise hydrogenation of products was performed in one-pot by Pd/C, with selective reduction of the double bonds, followed by deprotection of the benzyl group. In the experimental materials used by the author, we found 2-Bromonicotinaldehyde(cas: 128071-75-0HPLC of Formula: 128071-75-0)

2-Bromonicotinaldehyde(cas: 128071-75-0) belongs to pyridine. Pyridine is very deactivated towards electrophilic substitution with respect to benzene. For this reason classical formylation, using methods such as the Gattermann or Vilsmeier reactions, are not generally successful. HPLC of Formula: 128071-75-0

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2018,Mihai, Madalina T.; Davis, Holly J.; Genov, Georgi R.; Phipps, Robert J. published 《Ion Pair-Directed C-H Activation on Flexible Ammonium Salts: meta-Selective Borylation of Quaternized Phenethylamines and Phenylpropylamines》.ACS Catalysis published the findings.Formula: C7H9NO The information in the text is summarized as follows:

Ion pairing has unexplored potential as a key catalyst-substrate interaction for controlling regioselectivity and site-selectivity in transition-metal catalysis, particularly in the area of C-H activation. However, there is a significant perceived challenge that has meant that few have investigated this approach to date-that of the low directionality, which could present an unsurmountable challenge if seeking positional selectivity on flexible substrates. Herein, we demonstrate that even flexible substrates with several freely rotatable bonds undergo ion pair-directed C-H borylation with good to excellent levels of regiocontrol for the arene meta-position. Furthermore, we demonstrate that in specially designed competition substrates, ion pair direction prevails over competing hydrogen bond direction. We anticipate that these findings will inspire the greater incorporation of ion-pairing into site-selective catalytic strategies. In the experiment, the researchers used 2-(2-Hydroxyethyl)pyridine(cas: 103-74-2Formula: C7H9NO)

2-(2-Hydroxyethyl)pyridine(cas: 103-74-2) belongs to pyridine. Pyridine is a relatively complex molecule and exhibits a number of different bands in IR spectra. Among others, the bands characterizing the ν8a and ν19b modes have been found to be sensitive to the coordination or protonation of the molecule. Note that the band that is diagnostic for the PyH+ ion at about 1545 cm− 1 (ν19b mode) does not overlap with any of the other bands.Formula: C7H9NO

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2018,Nature Chemistry included an article by Park, Hojoon; Verma, Pritha; Hong, Kai; Yu, Jin-Quan. Computed Properties of C6H4BrNO. The article was titled 《Controlling Pd(IV) reductive elimination pathways enables Pd(II)-catalysed enantioselective C(sp3)-H fluorination》. The information in the text is summarized as follows:

The development of a Pd(II)-catalyzed enantioselective fluorination of C(sp3)-H bonds would offer a new approach to making chiral organofluorines. However, such a strategy is particularly challenging because of the difficulty in differentiating prochiral C(sp3)-H bonds through Pd(II)-insertion, as well as the sluggish reductive elimination involving Pd-F bonds. Here, authors report the development of a Pd(II)-catalyzed enantioselective C(sp3)-H fluorination using a chiral transient directing group strategy. In this work, a bulky, amino amide transient directing group was developed to control the stereochem. of the C-H insertion step and selectively promote the C(sp3)-F reductive elimination pathway from the Pd(IV)-F intermediate. Stereochem. anal. revealed that while the desired C(sp3)-F formation proceeds via an inner-sphere pathway with retention of configuration, the undesired C(sp3)-O formation occurs through an SN2-type mechanism. Elucidation of the dual mechanism allows us to rationalize the profound ligand effect on controlling reductive elimination selectivity from high-valent Pd species. In the part of experimental materials, we found many familiar compounds, such as 2-Bromonicotinaldehyde(cas: 128071-75-0Computed Properties of C6H4BrNO)

2-Bromonicotinaldehyde(cas: 128071-75-0) belongs to pyridine. When pyridine is adsorbed on oxide surfaces or in porous materials, the following species are commonly observed: (i) pyridine coordinated to Lewis acid sites, (ii) pyridine H-bonded to weakly acidic hydroxyls, and (iii) protonated pyridine. At high coverage, physisorbed pyridine and protonated dimers can also be observed.Computed Properties of C6H4BrNO

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem