Month: November 2022

Tomas, Federico M. A.; Peyrot, Analia M.; Fagalde, Florencia published their research in Polyhedron in 2021. The article was titled 《Synthesis, spectroscopic characterization and theoretical studies of polypyridine homoleptic Cu (I) complexes》.Computed Properties of C12H12N2 The article contains the following contents:

The authors focus on the synthesis and physicochem. characterization of four mononuclear copper(I) complexes with π-conjugated ligands substituted by Me groups of formulas [CuL2]+ with L = dmb, dmp, tmp and phen (dmb = 4,4′-dimethyl-2,2′-bipyridine; dmp = 5,6-dimethyl-1,10- phenanthroline; tmp = 3,4,7,8-tetramethyl-1,10-phenanthroline and phen = 1,10-phenanthroline). By TD-DFT it was possible to discuss and rationalize the geometry of the complexes and the origin of metal-to-ligand charge transfer in a square-planar distortion state. In the part of experimental materials, we found many familiar compounds, such as 4,4′-Dimethyl-2,2′-bipyridine(cas: 1134-35-6Computed Properties of C12H12N2)

4,4′-Dimethyl-2,2′-bipyridine(cas: 1134-35-6) is used as a chemical Intermediate. It can be used for the determination of ferrous and cyanide compounds.Computed Properties of C12H12N2 Furthermore, 4,4′-Dimethyl-2,2′-bipyridine is used in the synthesis of a series of o-phenanthroline-substituted ruthenium(II) complexes.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Singh, Anshu; Maji, Ankur; Joshi, Mayank; Choudhury, Angshuman R.; Ghosh, Kaushik published their research in Dalton Transactions in 2021. The article was titled 《Designed pincer ligand supported Co(II)-based catalysts for dehydrogenative activation of alcohols: Studies on N-alkylation of amines, α-alkylation of ketones and synthesis of quinolines》.Related Products of 1122-54-9 The article contains the following contents:

Base-metal catalysts Co1, Co2 and Co3 were synthesized from designed pincer ligands L1, L2 and L3 having NNN donor atoms, resp. Co1, Co2 and Co3 were characterized by IR, UV-visible and ESI-MS spectroscopic studies. Single crystal x-ray diffraction studies were studied to authenticate the mol. structures of Co1 and Co3. Catalysts Co1, Co2 and Co3 were used to study the dehydrogenative activation of alcs. for N-alkylation of amines, α-alkylation of ketones and synthesis of quinolines. Under optimized reaction conditions, a broad range of substrates including alcs., anilines and ketones were exploited. Control experiments for N-alkylation of amines, α-alkylation of ketones and synthesis of quinolines were examined to understand the reaction pathway. ESI-MS spectral studies were studied to characterize Co-alkoxide and Co-hydride intermediates. Reduction of styrene by evolved H gas during the reaction was studied to authenticate the dehydrogenative nature of the catalysts. Probable reaction pathways are proposed for N-alkylation of amines, α-alkylation of ketones and synthesis of quinolines from control experiments and detection of reaction intermediates. In the experimental materials used by the author, we found 4-Acetylpyridine(cas: 1122-54-9Related Products of 1122-54-9)

4-Acetylpyridine(cas: 1122-54-9) 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. Related Products of 1122-54-9

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Feng, Zengqiang; Zhu, Baoxiang; Dong, Bingbing; Cheng, Li; Li, Yunpu; Wang, Zechao; Wu, Junliang published their research in Organic Letters in 2021. The article was titled 《Visible-Light-Promoted Synthesis of α-CF2H-Substituted Ketones by Radical Difluoromethylation of Enol Acetates》.Electric Literature of C33H24IrN3 The article contains the following contents:

An efficient and novel visible-light-promoted radical difluoromethylation of enol acetates for the synthesis of α-CF2H-substituted ketones were described. Upon irradiation under blue LED with catalytic amounts of fac-Ir(ppy)3, this photocatalytic procedure employed difluoromethyltriphenylphosphonium bromide as a radical precursor. Various α-CF2H-substituted ketones were successfully created via designed systems based on the SET process. The methodol. were provided an operationally simple process with broad functional group compatibility. In the part of experimental materials, we found many familiar compounds, such as fac-Tris(2-phenylpyridine)iridium(cas: 94928-86-6Electric Literature of C33H24IrN3)

fac-Tris(2-phenylpyridine)iridium(cas: 94928-86-6) 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. Electric Literature of C33H24IrN3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Gong, Zhiming; Wang, Ru; Jiang, Yue; Kong, Xiangyu; Lin, Yue; Xu, Zhengjie; Zhou, Guofu; Liu, Jun-Ming; Kempa, Krzysztof; Gao, Jinwei published an article in 2021. The article was titled 《Novel D-A-D type small-molecular hole transport materials for stable inverted perovskite solar cells》, and you may find the article in Organic Electronics.HPLC of Formula: 624-28-2 The information in the text is summarized as follows:

Hole transport materials (HTMs), as a critical role in the hole extraction and transportation processes, highly influence the efficiency and stability of perovskite solar cells (PSCs). Despite that several efficient dopant-free HTMs have been reported, there is still no clear structure-property relationship that could give instructions for the rational mol. design of efficient HTMs. Thus, in this work, a series of donor-acceptor-donor (D-A-D) type carbazole-based small mols., TM-1 to TM-4, have been carefully designed and synthesized. By varing the electron acceptor unit from benzene to pyridine, pyrazine and diazine, their packing structure in single crystals, optical and electronic properties have shown a great difference. While as dopant-free HTM in p-i-n type PSCs, TM-2 improved the device photovoltaic performance with a power conversion efficiency from 15.02% (based on PEDOT:PSS) to 16.13%. Moreover, the unencapsulated device based on TM-2 retains about 80% of its initial efficiency after 500 h storage in ambient environment, showing the superior stability.2,5-Dibromopyridine(cas: 624-28-2HPLC of Formula: 624-28-2) was used in this study.

2,5-Dibromopyridine(cas: 624-28-2) 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. HPLC of Formula: 624-28-2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Griffin, Jeremy D.; Vogt, David B.; Du Bois, J.; Sigman, Matthew S. published an article in 2021. The article was titled 《Mechanistic Guidance Leads to Enhanced Site-Selectivity in C-H Oxidation Reactions Catalyzed by Ruthenium bis(Bipyridine) Complexes》, and you may find the article in ACS Catalysis.Product Details of 3510-66-5 The information in the text is summarized as follows:

The development of an operationally simple C-H oxidation protocol using an acid-stable, bis(bipyridine)Ru catalyst is described. Electronic differences remote to the site of C-H functionalization are found to affect product selectivity. Site-selectivity is further influenced by the choice of reaction solvent, with highest levels of 2° methylene oxidation favored in aqueous dichloroacetic acid. A statistical model is detailed that correlates product selectivity outcomes with computational parameters describing the relative “”electron-richness”” of C-H bonds. The results came from multiple reactions, including the reaction of 2-Bromo-5-methylpyridine(cas: 3510-66-5Product Details of 3510-66-5)

2-Bromo-5-methylpyridine(cas: 3510-66-5) 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.Product Details of 3510-66-5

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Cao, Liang; Zhao, He; Guan, Rongqing; Jiang, Huanfeng; Dixneuf, Pierre. H.; Zhang, Min published an article in 2021. The article was titled 《Practical iridium-catalyzed direct α-arylation of N-heteroarenes with (hetero)arylboronic acids by H2O-mediated H2 evolution》, and you may find the article in Nature Communications.SDS of cas: 1692-25-7 The information in the text is summarized as follows:

Despite the widespread applications of 2-(hetero)aryl N-heteroarenes in numerous fields of science and technol., universal access to such compounds is hampered due to the lack of a general method for their synthesis. Herein, by a H2O-mediated H2-evolution cross-coupling strategy, an iridium(III)-catalyzed facile method to direct α-arylation of N-heteroarenes with both aryl and heteroaryl boronic acids, proceeding with broad substrate scope and excellent functional compatibility, oxidant and reductant-free conditions, operational simplicity, easy scalability, and no need for prefunctionalization of N-heteroarenes is reported. This method is applicable for structural modification of biomedical mols., and offers a practical route for direct access to 2-(hetero)aryl N-heteroarenes, a class of potential cyclometalated CN̂ ligands and NN̂ bidentate ligands that are difficult to prepare with the existing α-C-H arylation methods, thus filling an important gap in the capabilities of synthetic organic chem. In the experiment, the researchers used Pyridin-3-ylboronic acid(cas: 1692-25-7SDS of cas: 1692-25-7)

Pyridin-3-ylboronic acid(cas: 1692-25-7) 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.SDS of cas: 1692-25-7

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Xu, Qun; Li, Tian; Chen, Hekai; Kong, Jun; Zhang, Liwei; Yin, Hang published an article in 2021. The article was titled 《Design and optimisation of a small-molecule TLR2/4 antagonist for anti-tumour therapy》, and you may find the article in RSC Medicinal Chemistry.COA of Formula: C6H7Br2N The information in the text is summarized as follows:

A small-mol. co-inhibitor that targets the TLR2/4 signalling pathway were developed. After high-throughput screening of a compound library containing 14400 small mols., followed by hit-to-lead structural optimization, the compound I was finally obtained, which has effective inhibitory properties against the TLR2/4 signalling pathways. This compound was found to significantly inhibit multiple pro-inflammatory cytokines released by RAW264.7 cells. This was followed by compound I demonstrating promising efficacy in subsequent anti-tumor experiments The current results provided a novel understanding of the role of TLR2/4 in cancer and a novel strategy for anti-tumor therapy. After reading the article, we found that the author used 2-(Bromomethyl)pyridine hydrobromide(cas: 31106-82-8COA of Formula: C6H7Br2N)

2-(Bromomethyl)pyridine hydrobromide(cas: 31106-82-8) 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.COA of Formula: C6H7Br2N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2022,Itagaki, Ren; Takizawa, Shin-ya; Chang, Ho-Chol; Nakada, Akinobu published an article in Dalton Transactions. The title of the article was 《Light-induced electron transfer/phase migration of a redox mediator for photocatalytic C-C coupling in a biphasic solution》.Synthetic Route of C12H12N2 The author mentioned the following in the article:

Photocatalytic mol. conversions that lead to value-added chems. are of considerable interest. To achieve highly efficient photocatalytic reactions, it is equally important as it is challenging to construct systems that enable effective charge separation Here, we demonstrate that the rational construction of a biphasic solution system with a ferrocenium/ferrocene (Fc+/Fc) redox couple enables efficient photocatalysis by spatial charge separation using the liquid-liquid interface. In a single-phase system, exposure of a 1,2-dichloroethane (DCE) solution containing a Ru(II)- or Ir(III)-based photosensitizer, Fc, and benzyl bromide (Bn-Br) to visible-light irradiation failed to generate any product. However, the photolysis in a H2O/DCE biphasic solution, where the compounds are initially distributed in the DCE phase, facilitated the reductive coupling of Bn-Br to dibenzyl (Bn2) using Fc as an electron donor. The key result of this study is that Fc+, generated by photooxidation of Fc in the DCE phase, migrates to the aqueous phase due to the drastic change in its partition coefficient compared to that of Fc. This liquid-liquid phase migration of the mediator is essential for facilitating the reduction of Bn-Br in the DCE phase as it suppresses backward charge recombination. The co-existence of anions can further modify the driving force of phase migration of Fc+ depending on their hydrophilicity; the best photocatalytic activity was obtained with a turnover frequency of 79.5 h-1 and a quantum efficiency of 0.2% for the formation of Bn2 by adding NBu4+Br- to the biphasic solution This study showcases a potential approach for rectifying electron transfer with suppressed charge recombination to achieve efficient photocatalysis. The experimental part of the paper was very detailed, including the reaction process of 4,4′-Dimethyl-2,2′-bipyridine(cas: 1134-35-6Synthetic Route of C12H12N2)

4,4′-Dimethyl-2,2′-bipyridine(cas: 1134-35-6) is used as a chemical Intermediate. It can be used for the determination of ferrous and cyanide compounds.Synthetic Route of C12H12N2 Furthermore, 4,4′-Dimethyl-2,2′-bipyridine is used in the synthesis of a series of o-phenanthroline-substituted ruthenium(II) complexes.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

In 2022,Biallas, Phillip; Yamazaki, Ken; Dixon, Darren J. published an article in Organic Letters. The title of the article was 《Difluoroalkylation of Tertiary Amides and Lactams by an Iridium-Catalyzed Reductive Reformatsky Reaction》.Recommanded Product: 3510-66-5 The author mentioned the following in the article:

An iridium catalyzed, reductive alkylation of abundant tertiary lactams and amides using 1-2 mol % of Vaska’s complex (IrCl(CO)(PPh3)2), tetramethyldisiloxane (TMDS) and difluoro-Reformatsky reagents (BrZnCF2R) for the general synthesis of medicinally relevant α-difluoroalkylated tertiary amines, is described. A broad scope (42 examples), including N-aryl and N-heteroaryl substituted lactams, demonstrated an excellent functional group tolerance. Furthermore, late-stage drug functionalizations, a gram scale synthesis and common downstream transformations proved the potential synthetic relevance of this new methodol. In the experiment, the researchers used 2-Bromo-5-methylpyridine(cas: 3510-66-5Recommanded Product: 3510-66-5)

2-Bromo-5-methylpyridine(cas: 3510-66-5) 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. Recommanded Product: 3510-66-5

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Takata, Toshihiro published an article in 1962, the title of the article was Synthesis of methylpyridine and 1,8-naphthyridine derivatives.Safety of 3-Methylpyridine-2,6-diamine And the article contains the following content:

When a mixture of 43 g. α,α’-dimethylglutaronitrile (I) and 30 g. NaNH2 in 258 ml. HCONH2 was kept for 2 days, filtered, and washed with PrOH and EtOAc, 41 g. α,α’-dimethylglutarimidine (II), m. 209-10° (decomposition) (absolute EtOH), was obtained. Similarly α-methylglutaronitrile gave 70% of α-methylglutarimidine (III), m. 154-5° (decomposition) (absolute EtOH). Reduction of 7 g. II in 100 ml. absolute EtOH was carried out with 98 g. Na and excess EtOH. Steam distillation of the product and evaporation of the acidified distillate and basification with NaOH gave 4.6 g. 3,5-dimethylpiperidine (IV), b. 144°, d20 0.8532, n20D 1.4560; picrate m. 184°. Reduction of III gave 3-methylpiperidine (V), b. 125-6°, d20 0.8570, n20D 1.4506; picrate m. 105°. Dehydrogenation of 0.5 g. IV with 0.2 g. of a Pd catalyst gave 0.35 g. 3,5-dimethylpyridine (VI), b. 168-71°, d20 0.9096, n20D 1.4501; picrate m. 242-3° (decomposition). 3-Methylpyridine (VII) was obtained similarly from V; picrate m. 149-50°. Dehydrogenation of 1 g. II in 4 ml. Ph2O at 300° for 11 hrs. with Pd catalyst gave 0.3 g. 2,6-diamino-3,5-dimethylpyridine (VIII), m. 186-7° (C6H6). VIII was acetylated with Ac2O in a sealed tube at 170° for 1 hr. to give the tetraacetyl derivative (IX), m. 149° (C6H6). Acetylation of VIII at 95° for 1 hr. gave the diacetyl derivative (X), m. 197°. 2,6-Diamino-3-methylpyridine (XI), m. 156-7°, was obtained in 30% yield by the dehydrogenation of III with Pd catalyst. Treatment of 12.2 g. VII with 16 g. NaNH2 in 16 g. Tetralin at 150-3° for 4 hrs. and at 198-200° for 17 hrs. and pouring the mixture into H2O and extraction with C6H6 and evaporation gave 2.5 g. XI. Acetylation of XI with Ac2O at 170-180° for 3 hrs. gave the triacetyl derivative, m. 142-4°. Acetylation of XI with Ac2O at 90-100° for 1 hr. gave the diacetyl derivative, m. 220-1°. Treatment of 2,4,6-tricyano-n-heptane (XII) with NaNH2 as before gave 3,6-dihydro-2,7-diiminooctahydro-1,8-naphthyridine (XIII), m. 222-4° (decomposition), in 87% yield and 1,3,5-tricyanohexane (XIV) gave 3-methyl-2,7-diiminooctahydro-1,8-naphthyridine (XV), m. 204-6° (decomposition), in 65% yield, while 1,3,5-tricyanopentane (XVI) gave 2,7-diiminooctahydro-1,8-naphthyridine (XVII) in 82% yield. A solution of 1.5 g. XIII in 240 ml. amyl alcohol was reduced with 21 g. Na at 130-40°. Working up as for IV gave 1 g. 3,6-dimethyldecahydro-1,8-naphthyridine (XVIII), m. 162-3° (C6H6); dipicrate m. 213° (decomposition). Similar reductions of 7 g. XV in 800 ml. amyl alcohol and 98 g. Na gave 4 g. 3-methyldecahydro-1,8-naphthyridine (XIX), m. 116-17° [dipicrate m. 205° (decomposition)] and of 1.2 g. XVII with 17 g. Na gave 0.9 g. decahydro-1,8-naphthyridine (XX), m. 116-17° (dipicrate m. 195°). Dehydrogenation of XVIII with a Pd catalyst in Ph2O gave 3,6-dimethyl-1,8-naphthyridine (XXI), m. 191-2° (petr. ether) in 71% yield; picrate m. 210-11° (decomposition). To a mixture of 320 g. CH2(CO2Et)2 (XXII) and 280 g. CH2:CMeCN was added a solution of 11 g. Na in 80 g. EtOH and the mixture stirred at 30-50° for 8 hrs. and at 80-90° for 2 hrs. Addition of HCl, and distillation of the product gave 338 g. α,α’-dimethyl-γ,-γ-dicarbethoxypimelonitrile (XXIII), b2 175°. γ,γ-Dicarbethoxypimeronitrile (XXIV), m. 60-2°, was obtained in 76% yield from 187 g. XXII, and 123 g. acrylonitrile and 10.6 ml. of 30% KOH in aqueous MeOH at room temperature for 2 hrs. XXIII (115 g.) was hydrolyzed with 55 g. KOH in 500 ml. absolute EtOH for a few days at room temperature Addition of water, acidification, and extraction with EtOAc gave α,α’-dimethyl-γ,γ-dicarboxypimelonitrile (XXV), m. 134-6° (decomposition). Similarly XXIV gave the corresponding diacid (XXVI), m. 158°. The K salt of XXV (47.1 g.) in 50% aqueous EtOH was treated with H at 100 atm. below 60° in the presence of 19 g. Raney Ni catalyst and the mixture was concentrated, acidified, and heated at 200° for 3 hrs. Addition of NaOEt in EtOH gave 20 g. 3-(β-methyl-ω-aminopropyl)-5-methyl-2-piperidone (XXVII); picrate m. 184-6°. Pyrolysis of 0.7 g. XXVII at 300° gave after purification as the hydrochloride and basification, 3,6-dimethyltetrahydro-1,8-naphthyridine (XXVIII), m. 110-11°; monopicrate m. 256°. Dehydrogenation of 0.11 g. XXVIII in 2 ml. Ph2O at 250-80° for 20 hrs. in the presence of Pd catalyst gave XXI. Reduction of XXVIII with Na in amyl alcohol gave XVIII. Reduction of 28 g. K salt of XXVI with Raney Ni as for XXV gave 13 g. 3-(ω-aminopropyl)-2-piperidone (XXIX); picrate m. 207°. Pyrolysis of XXIX gave hexahydro-1,8-naphthyridine; picrate m. 228-30°. The experimental process involved the reaction of 3-Methylpyridine-2,6-diamine(cas: 51566-22-4).Safety of 3-Methylpyridine-2,6-diamine

3-Methylpyridine-2,6-diamine(cas:51566-22-4) belongs to pyridine-derivatives. Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Safety of 3-Methylpyridine-2,6-diamine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem