Day: November 8, 2022

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

In 2019,Dalton Transactions included an article by Wang, Yaqin; Xu, Xinxin; Liu, Luyao; Chen, Jin; Shi, Guimei. Related Products of 1134-35-6. The article was titled 《A coordination polymer-derived Co3O4/Co-N@NMC composite material as a Zn-air battery cathode electrocatalyst and microwave absorber》. The information in the text is summarized as follows:

Zn-air batteries, promising energy storage equipment with high energy d., light weight and a compact structure, are a perfect power source for elec. vehicles. For a Zn-air battery, the activity of the air cathode electrocatalyst plays an important role in its performance. Here, employing a coordination polymer as a precursor, a composite material built from Co3O4 and Co-N active centers with nitrogen-doped mesoporous carbon as a matrix has been synthesized successfully. This composite material possesses outstanding activity and stability in the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) processes. It possesses a small half-wave potential (ORR1/2 = 0.786 V) and low overpotential (OER10 = 1.575 V) for the ORR and OER, resp. With this composite material as an air cathode electrocatalyst, a rechargeable Zn-air battery was assembled successfully. During the discharge process, the maximum power d. of this Zn-air battery is 122 mW cm-2 at 0.76 V. The specific capacity of this battery is 505 mA h g-1 at 25 mA cm-2. The voltage gap between the charge and discharge processes is only 0.744 V at 10 mA cm-2 and 1.308 V at 100 mA cm-2. This rechargeable battery also shows promising stability after long-term charge-discharge experiments Furthermore, the composite material also exhibits outstanding microwave adsorption properties. Its maximum reflection loss (RL) arrives at -13.9 dB with a thickness of only 1.0 mm. Thus, we find that coordination polymers are an ideal precursor for Zn-air battery cathode electrocatalysts and microwave absorbers. In the experiment, the researchers used many compounds, for example, 4,4′-Dimethyl-2,2′-bipyridine(cas: 1134-35-6Related Products of 1134-35-6)

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.Related Products of 1134-35-6 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 2019,Polymer included an article by Allegrezza, Michael L.; Thompson, Adam M.; Kloster, Alex J.; Konkolewicz, Dominik. SDS of cas: 94928-86-6. The article was titled 《Efficient coupling by oxygen accelerated photocatalyzed thiol-alkyne chemistry》. The information in the text is summarized as follows:

Thiol reactions have gained attention in many areas of chem. research, such as organic small mol. synthesis, polymer synthesis, and bimol. coupling due to the “”click”” chem. characteristics of this process. This work is a study of a novel method of photochem. thiol-alkyne reactions using alkyl halides and an Ir(ppy)3 photocatalyst. This process is shown to lead to rapid reactions and has the benefit of low catalyst and initiator concentrations relative to reagents. Remarkably, this reaction also has an unusual feature of an increased rate in the presence of oxygen, in contrast to many other types of radical processes. Catalyst and initiator concentrations and reaction conditions are varied in order to gain an understanding of the mechanism of this process. This chem. is then applied to the synthesis of hyperbranched polymers and polymer networks to demonstrate potential applications. In the experiment, the researchers used fac-Tris(2-phenylpyridine)iridium(cas: 94928-86-6SDS of cas: 94928-86-6)

fac-Tris(2-phenylpyridine)iridium(cas: 94928-86-6) belongs to pyridine. Pyridines are often used as catalysts or reagents; particular notice has been paid recently to how pyridine coordinates to metal centers enabling a wide range of valuable reactions. SDS of cas: 94928-86-6

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

The author of 《Modulating the blue shift of phosphorescence with fluorine-free group in iridium (III) complexes》 were Gao, Ying; Ding, Shuang; Su, Zhong-Min; Geng, Yun. And the article was published in Journal of Luminescence in 2019. Recommanded Product: 98-98-6 The author mentioned the following in the article:

In this work, iridium complexes 1-8 bearing bipyridine or pyridine-pyrimidine main ligand and picolinate ancillary ligand have been designed by varying the position of -OCH3 and Ph groups at the ligands aiming at finding a better choice to design blue phosphors. The results indicate that an appropriate combination of -OCH3 and pyridine-pyrimidine ligand makes the emission wavelength a noticeable blue-shift. Moreover, the further introduction of Ph group shifts the emission wavelength to a shorter region. In terms of the radiative decay rate constant (kr), the position of -OCH3 has a slight influence on it, but the introduction of Ph group is conductive to enhancing this value. In particular, the 7 has the largest kr among the designed complexes up to 7.68 × 105 s-1. As for the non-radiative process, 1-6 have high barriers between 3MLCT and 3MC, indicating the difficulty of electron relaxation to the non-emissive 3MC structure. There is no transition state of 3MLCT↔3MC is found for 7 and 8 bearing pyridine-pyrimidine ligand. However, the barriers of all complexes for the S0/3MC min. energy crossing point reaction are high, which is in favor of avoiding the system relaxes to the S0 geometry by non-radiative path. In the experiment, the researchers used many compounds, for example, Picolinic acid(cas: 98-98-6Recommanded Product: 98-98-6)

Picolinic acid(cas: 98-98-6) is used as a chelate for alkaline earth metals. Used to prepare picolinato ligated transition metal complexes. In synthetic organic chemistry, has been used as a substrate in the Mitsunobu reaction and in the Hammick reaction.Recommanded Product: 98-98-6

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Arabidopsis PIC30 encodes a major facilitator superfamily transporter responsible for the uptake of picolinate herbicides》 was published in Plant Journal in 2020. These research results belong to Kathare, Praveen K.; Dharmasiri, Sunethra; Vincill, Eric D.; Routray, Pratyush; Ahmad, Idrees; Roberts, Daniel M.; Dharmasiri, Nihal. COA of Formula: C6H5NO2 The article mentions the following:

However, its mechanism of transport into plants is poorly understood. In a genetic screen for picloram resistance, we identified three Arabidopsis mutant alleles of PIC30 (PICLORAM RESISTANT30) that are specifically resistant to picolinates, but not to other auxins. PIC30 is a previously uncharacterized gene that encodes a major facilitator superfamily (MFS) transporter. Similar to most members of MFS, PIC30 contains 12 putative transmembrane domains, and PIC30-GFP fusion protein selectively localizes to the plasma membrane. In planta transport assays demonstrate that PIC30 specifically transports picloram, but not indole-3-acetic acid (IAA). Functional anal. of Xenopus laevis oocytes injected with PIC30 cRNA demonstrated PIC30 mediated transport of picloram and several anions, including nitrate and chloride. Consistent with these roles of PIC30, three allelic pic30 mutants are selectively insensitive to picolinate herbicides, while pic30-3 is also defective in chlorate (analog of nitrate) transport and also shows reduced uptake of 15NO3-. Overexpression of PIC30 fully complements both picloram and chlorate insensitive phenotypes of pic30-3. Despite the continued use of picloram as an herbicide, a transporter for picloram was not known until now. This work provides insight into the mechanisms of plant resistance to picolinate herbicides and also shed light on the possible endogenous function of PIC30 protein. The experimental process involved the reaction of Picolinic acid(cas: 98-98-6COA of Formula: C6H5NO2)

Picolinic acid(cas: 98-98-6) is used in the preparation of 2-Aminodihydro[1,3]thiazines as BACE 2 inhibitors and their preparation and use in the treatment of diabetes.COA of Formula: C6H5NO2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《More efficient spin-orbit coupling: adjusting the ligand field strength to the second metal ion in asymmetric binuclear platinum(II) configurations》 was published in Dalton Transactions in 2020. These research results belong to Hao, Zhaoran; Zhang, Kai; Chen, Kuan; Wang, Pu; Lu, Zhiyun; Zhu, Weiguo; Liu, Yu. Category: pyridine-derivatives The article mentions the following:

Two types of asym. binuclear platinum(II) complexes (Pt-1 and Pt-3) bearing bridging ligands of 2-(2,4-difluorophenyl)-5-(pyridin-2-yl)pyridine and 2-(2,4-difluorophenyl)-4-(pyridin-2-yl)pyridine as well as their corresponding mononuclear counterparts (Pt-2, Pt-4, and Pt-5) were synthesized and characterized. Different chelating constructions of the second platinum(II) ions and the bridging ligands in Pt-1 and Pt-3 gave rise to two kinds of electron-transition pathway during their photophys. processes. The meta-/para-carbon of nitrogen on the center pyridyl segments set different levels of ligand field strength to the second platinum(II) ions, lowering their occupied d orbital to varying degrees. Pt-1 showed an enhanced spin-orbit coupling (SOC), caused by the addnl. metal component through direct orbital hybridization at higher states, where the fixed mol. skeleton induced by the addnl. metal-ligand bonding also helped to suppress mol. distortion in the excited state, ensuring a high quantum yield (Φ, 0.89 in toluene), which is among the best results in bimetallic complexes. While the second platinum(II) ion in Pt-3 seemed to make no contribution to the radiative transition, and only contributed to the HOMO, it provided a benefit by enlarging the conjugate system. Solution-processed organic lighting emitting devices (OLEDs) fabricated with the bimetallic Pt-1 emitter achieved superior efficiencies and up to 21% external quantum efficiency (EQE) in the Kelly-green region. In the part of experimental materials, we found many familiar compounds, such as 2,5-Dibromopyridine(cas: 624-28-2Category: pyridine-derivatives)

2,5-Dibromopyridine(cas: 624-28-2) 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. Category: pyridine-derivatives

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《Visible-Light-Induced Deoxygenation/Defluorination Protocol for Synthesis of γ,γ-Difluoroallylic Ketones》 was published in Organic Letters in 2020. These research results belong to Guo, Yuan-Qiang; Wang, Ruiguo; Song, Hongjian; Liu, Yuxiu; Wang, Qingmin. Electric Literature of C5H6BNO2 The article mentions the following:

Herein, we describe an efficient, practical photocatalytic deoxygenation/defluorination protocol for the synthesis of γ,γ-difluoroallylic ketones from com. available aromatic carboxylic acids, triphenylphosphine, and α-trifluoromethyl alkenes. The protocol has good functional group tolerance and a broad substrate scope. Using this method, we accomplished the late-stage functionalization of several bioactive mols. The experimental part of the paper was very detailed, including the reaction process of Pyridin-3-ylboronic acid(cas: 1692-25-7Electric Literature of C5H6BNO2)

Pyridin-3-ylboronic acid(cas: 1692-25-7) 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 C5H6BNO2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

《The Synthesis of Primary Amines through Reductive Amination Employing an Iron Catalyst》 was published in ChemSusChem in 2020. These research results belong to Baeumler, Christoph; Bauer, Christof; Kempe, Rhett. Related Products of 1122-54-9 The article mentions the following:

Iron-catalyzed synthesis of primary amines through reductive amination was realized. A broad scope and a very good tolerance of functional groups were observed Ketones, including purely aliphatic ones, aryl-alkyl, dialkyl, and heterocyclic, as well as aldehydes were converted smoothly into their corresponding primary amines. In addition, the amination of pharmaceuticals, bioactive compounds, and natural products was demonstrated. Many functional groups, such as hydroxy, methoxy, dioxol, sulfonyl, and boronate ester substituents, were tolerated. The catalyst is easy to handle, selective, and reusable and ammonia dissolved in water could be employed as the nitrogen source. The key feature of this method includes the use of a specific Fe complex for the catalyst synthesis and an N-doped SiC material as catalyst support. The experimental process involved the reaction of 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

《One-Pot Regiodirected Annulations for the Rapid Synthesis of π-Extended Oligomers》 was written by Nitti, Andrea; Osw, Peshawa; Calcagno, Giuseppe; Botta, Chiara; Etkind, Samuel I.; Bianchi, Gabriele; Po, Riccardo; Swager, Timothy M.; Pasini, Dario. Recommanded Product: 128071-75-0 And the article was included in Organic Letters in 2020. The article conveys some information:

Synthesis of fused benzoheterocycles e.g. I [R = H, Me] and II [X = S, O, N-Me; R1 = H, CO2Me] via one-pot regiospecific palladium catalyzed direct arylation (DHA) and cross aldol condensation of ortho-bromoaldehydes and 3-thiopheneacetic acid was reported. Direct arylation of 2-octyldodecyl benzo[b]thienobenzothiophene-4-carboxylates with 4,7-dibromobenzo[c][1,2,5]thiadiazole using palladium catalyst afforded benzodithiophene-containing oligomers III [R2 = R3 = H, R4 = 2-octyldecyl] and IV [R5 = R5 = H, R7 = 2-octyldecyl]. Preparation of benzodithiophene-containing oligomers III [R2 = R3 = F, R4 = 2-octyldecyl ] and IV [R5 = R6 = F, R7 = 2-octyldecyl] was developed via palladium catalyzed Stille reaction of 2-octyldodecyl 2-(tributylstannyl)benzo[b]thienobenzothiophene-4-carboxylates with 4,7-dibromo-5,6-difluorobenzo[c][1,2,5]thiadiazole. In the experimental materials used by the author, we found 2-Bromonicotinaldehyde(cas: 128071-75-0Recommanded Product: 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. Recommanded Product: 128071-75-0

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem