Month: October 2022

Zhong, Rui; Wei, Zeyuan; Zhang, Wei; Liu, Shun; Liu, Qiang published the artcile< A Practical and Stereoselective In Situ NHC-Cobalt Catalytic System for Hydrogenation of Ketones and Aldehydes>, Name: 1-(Pyridin-3-yl)ethanone, the main research area is cobalt complex catalyst preparation; secondary alc primary preparation diastereoselective; ketone hydrogenation cobalt catalyst; aldehyde hydrogenation cobalt catalyst.

Herein, a practical in situ catalytic system generated by easily available pincer NHC precursors, CoCl2 and a base enabled efficient and high-yielding hydrogenation of a broad range of ketones and aldehydes (over 50 examples and a maximum turnover number [TON] of 2,610) to afford alcs. was reported. This was the first example of NHC-Co-catalyzed hydrogenation of C=O bonds using flexible pincer NHC ligands consisting of a N-H substructure. Diastereodivergent hydrogenation of substituted cyclohexanone derivatives was also realized by fine-tuning of the steric bulk of pincer NHC ligands. Addnl., a bis(NHCs)-Co complex was successfully isolated and fully characterized and it exhibited excellent catalytic activity that equals that of the in-situ-formed catalytic system.

Chem published new progress about Alcohols Role: PRP (Properties), SPN (Synthetic Preparation), PREP (Preparation). 350-03-8 belongs to class pyridine-derivatives, and the molecular formula is C7H7NO, Name: 1-(Pyridin-3-yl)ethanone.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Wang, Jing; Chen, Le; Liu, Ying; Olajide, Tosin Michael; Jiang, Yuanrong; Cao, Wenming published the artcile< Identification of key aroma-active compounds in beef tallow varieties using flash GC electronic nose and GC x GC-TOF/MS>, Reference of 93-60-7, the main research area is aroma active compound beef GC electronic nose.

To uncover the integral flavor characteristics and individual odor active compounds in tallow derived from different beef fats: inguinal (IF), omental (OF), and perirenal fats (PF), we used flash GC electronic nose (flash GC E-nose) to analyze and characterize the samples. GC x GC-TOF/MS identified and quantified 195 volatile compounds with significant differences amongst the three kinds of fats. There were 45 important odorants (ROAV > 0.1) containing 23 key odorants (ROAV > 1), of which 43, 34, 35 important odorants were found in IF, OF, and PF, resp. Our results showed that the key odorants overall probably contribute to a fatty and sweat acid smell in IF, a meaty and slightly sweet taste in OF, and sweetness and slightly meaty taste in PF. Elucidating the distribution of key odorants in beef tallow from different parts of animals could provide a scientific basis for formulating and selecting raw materials of high-quality beef tallow flavor products.

European Food Research and Technology published new progress about Acids Role: BSU (Biological Study, Unclassified), BIOL (Biological Study). 93-60-7 belongs to class pyridine-derivatives, and the molecular formula is C7H7NO2, Reference of 93-60-7.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Abou-Elkhair, Reham A. I.; Hassan, Abdalla E. A.; Boykin, David W.; Wilson, W. David published the artcile< Lithium Hexamethyldisilazane Transformation of Transiently Protected 4-Aza/Benzimidazole Nitriles to Amidines and their Dimethyl Sulfoxide Mediated Imidazole Ring Formation>, Safety of 2-Amino-3-nitro-6-picoline, the main research area is lithium hexamethyldisilazane transiently protected azabenzimidazole nitrile; DMSO imidazole ring formation; amidine preparation.

Trimethylsilyl-transient protection successfully allowed the use of lithium hexamethyldisilazane to prepare benzimidazole (BI) and 4-azabenzimidazole (azaBI) amidines from nitriles in 58-88% yields. This strategy offers a much better choice to prepare BI/azaBI amidines than the lengthy, low-yielding Pinner reaction. Synthesis of aza/benzimidazole rings from aromatic diamines and aldehydes was affected in DMSO in 10-15 min, while known procedures require long time and purification These methods are important for the BI/azaBI-based drug industry and for developing specific DNA binders for expanded therapeutic applications.

Organic Letters published new progress about Amidines Role: SPN (Synthetic Preparation), PREP (Preparation). 21901-29-1 belongs to class pyridine-derivatives, and the molecular formula is C6H7N3O2, Safety of 2-Amino-3-nitro-6-picoline.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Grushin, Vladimir V.; Herron, Norman; LeCloux, Daniel D.; Marshall, William J.; Petrov, Viacheslav A.; Wang, Ying published the artcile< New, efficient electroluminescent materials based on organometallic Ir complexes>, Product Details of C33H21F3IrN3, the main research area is crystal structure iridium cyclometalated fluorinated arylpyridine complex; mol structure iridium cyclometalated fluorinated arylpyridine complex; electroluminescent fluorinated organometallic iridium compound preparation; LED photoluminescence luminescence iridium cyclometalated fluorinated arylpyridine complex; reduction potential cyclometalated fluorinated iridium arylpyridine complex; oxidation potential cyclometalated fluorinated iridium arylpyridine complex; fluorinated cyclometalated arylpyridine iridium complex preparation electroluminescent property; phenylpyridine cyclometalated fluorinated iridium complex preparation electroluminescent property; pyridine phenyl cyclometalated fluorinated iridium complex preparation electroluminescent property.

Reaction of aqueous IrCl3 with fluorinated 2-arylpyridines in the presence of AgO2CCF3 afforded fifteen fac-tris-cyclometalated arylpyridine Ir complexes (e.g., I) exhibiting excellent processing and electroluminescent properties which can be fine-tuned via systematic control of the nature and position of the substituents on the aromatic rings. Single-crystal x-ray structures were obtained for I and three other analogous cyclometalated arylpyridine Ir complexes. Nearly all the arylpyridine Ir complexes exhibited fully reversible reduction and oxidation waves.

Chemical Communications (Cambridge, United Kingdom) published new progress about Crystal structure. 370878-69-6 belongs to class pyridine-derivatives, and the molecular formula is C33H21F3IrN3, Product Details of C33H21F3IrN3.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Mangas-Sanchez, Juan; Sharma, Mahima; Cosgrove, Sebastian C.; Ramsden, Jeremy I.; Marshall, James R.; Thorpe, Thomas W.; Palmer, Ryan B.; Grogan, Gideon; Turner, Nicholas J. published the artcile< Asymmetric synthesis of primary amines catalyzed by thermotolerant fungal reductive aminases>, Category: pyridine-derivatives, the main research area is ketone ammonia fungal aminase catalyst enantioselective reductive amination; amine preparation.

The structural and biochem. characterization as well as synthetic applications of two RedAms from Neosartorya spp. was described. (NfRedAm and NfisRedAm) that displayed a distinctive activity amongst fungal RedAms, namely a superior ability to use ammonia as the amine partner. Using these enzymes, The synthesis of a broad range of primary amines, with conversions up to >97% and excellent enantiomeric excess was demonstrated . Temperature dependent studies showed that these homologues also possess greater thermal stability compared to other enzymes within this family. Their synthetic applicability was further demonstrated by the production of several primary and secondary amines with turnover numbers (TN) up to 14 000 as well as continous flow reactions, obtaining chiral amines such as (R)-2-aminohexane in space time yields up to 8.1 g L-1 h-1. The remarkable features of NfRedAm and NfisRedAm highlight their potential for wider synthetic application as well as expanding the biocatalytic toolbox available for chiral amine synthesis.

Chemical Science published new progress about Amines Role: BPN (Biosynthetic Preparation), RCT (Reactant), BIOL (Biological Study), PREP (Preparation), RACT (Reactant or Reagent). 350-03-8 belongs to class pyridine-derivatives, and the molecular formula is C7H7NO, Category: pyridine-derivatives.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Carson, Matthew W.; Giese, Matthew W.; Coghlan, Michael J. published the artcile< An Intra/Intermolecular Suzuki Sequence to Benzopyridyloxepines Containing Geometrically Pure Exocyclic Tetrasubstituted Alkenes>, Recommanded Product: Methyl 3-bromo-2-pyridinecarboxylate, the main research area is bromopyridine alkyne pinacolatodiboron stereoselective diboration; aryloxy bromopyridine vinylpinacol boronic ester intramol Suzuki coupling palladium; benzopyridyloxepine dioxaborolanylethylidene iodoarene Suzuki coupling palladium; benzylidenyl benzopyridyloxepine derivative preparation; palladium Suzuki couplibng catalyst.

A route to enable the preparation of 5-benzylidenyl-benzopyridyloxepine analogs, e.g., I (R1 = Me, Et, i-Pr; R2 = H, F, MeO), was developed to continue our research in the field of nuclear hormone receptor modulators. The key steps are: 1. a syn-stereoselective diboration of a tethered aryl alkyne; 2. an intramol. Suzuki cross-coupling reaction, which forms in a stereo- and regiocontrolled fashion, the 5-exoalkylidenyl 7-membered ring imbedded within the core of the scaffold and; 3. an intermol. Suzuki to furnish the final tetra-substituted olefinic benzopyridyloxepines.

Organic Letters published new progress about Aliphatic alcohols Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation) (pyridylmethyl). 53636-56-9 belongs to class pyridine-derivatives, and the molecular formula is C7H6BrNO2, Recommanded Product: Methyl 3-bromo-2-pyridinecarboxylate.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Hilton, Margaret J.; Cheng, Bin; Buckley, Benjamin R.; Xu, Liping; Wiest, Olaf; Sigman, Matthew S. published the artcile< Relative reactivity of alkenyl alcohols in the palladium-catalyzed redox-relay Heck reaction>, Safety of (S)-4-(tert-Butyl)-2-(5-(trifluoromethyl)pyridin-2-yl)-4,5-dihydrooxazole, the main research area is reactivity alkenyl alc palladium catalyzed relay Heck; Heck reaction; competition experiments; redox-relay; relative rates of alkenes.

The relative rates of alkenyl alcs. in the Pd-catalyzed redox-relay Heck reaction were measured to examine the effect of their steric and electronic properties on the rate-determining step. Competition experiments between an allylic alkenyl alc. and two substrates with differing chain lengths revealed that the allylic alc. reacts 3-4 times faster in either case. Competition between di- and trisubstituted alkenyl alcs. provided an interesting scenario, in which the disubstituted alkene was consumed first followed by reaction of the trisubstituted alkene. Consistent with this observation, the transition structures for the migratory insertion of the aryl group into the di- and trisubstituted alkenes were calculated with a lower barrier for the former. An internal competition between a substrate containing two alcs. with differing chain lengths demonstrated the catalyst’s preference for migrating toward the closest alc. Addnl., increasing the electron-d. in the arene boronic acid promotes a faster reaction, which correlates with Hammett σp values to give a ρ of -0.87.

Tetrahedron published new progress about Alkenyl alcohols Role: PEP (Physical, Engineering or Chemical Process), PRP (Properties), RCT (Reactant), SPN (Synthetic Preparation), PROC (Process), RACT (Reactant or Reagent), PREP (Preparation). 1416819-91-4 belongs to class pyridine-derivatives, and the molecular formula is C13H15F3N2O, Safety of (S)-4-(tert-Butyl)-2-(5-(trifluoromethyl)pyridin-2-yl)-4,5-dihydrooxazole.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Li, Chun; Lu, Xunhua; Wang, Mengna; Zhang, Ling; Jiang, Jian; Yan, Shunfa; Yang, Yuanyong; Zhao, Yonglong; Zhang, Lin published the artcile< A simple and efficient asymmetric hydrogenation of heteroaromatic ketones with iridium catalyst composed of chiral diamines and achiral phosphines>, Application In Synthesis of 350-03-8, the main research area is heteroaromatic ketone iridium catalyst stereoselective enantioselective hydrogenation; heteroaryl alc preparation.

An efficient iridium catalyst composed of a simple and com. available o-methoxytriphenylphosphine and 9-Amino (9-deoxy) epi-cinchonine was applied to the asym. hydrogenation of heteroaromatic ketones. A range of simple heteroaromatic ketones were hydrogenated with good to excellent enantioselectivities and high activities. In particular, thiophene ketones and furyl ketones furnished 98.6% ee with up to 2.18 x 104(1/h) TOF. This catalytic system was of practical value.

Tetrahedron Letters published new progress about Enantioselective synthesis. 350-03-8 belongs to class pyridine-derivatives, and the molecular formula is C7H7NO, Application In Synthesis of 350-03-8.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Yang, Lichen; Uemura, Nao; Nakao, Yoshiaki published the artcile< meta-Selective C-H Borylation of Benzamides and Pyridines by an Iridium-Lewis Acid Bifunctional Catalyst>, Category: pyridine-derivatives, the main research area is meta selective borylation benzamide pyridine iridium aluminum bifunctional catalyst; borane pyridyl benzamide derivative preparation.

The authors report herein the Ir-catalyzed meta-selective C-H borylation of benzamides by using a newly designed 2,2′-bipyridine (bpy) ligand bearing an alkylaluminum biphenoxide moiety. The authors also demonstrate the Ir-catalyzed C3-selective C-H borylation of pyridine with a 1,10-phenanthroline (Phen) ligand bearing an alkylborane moiety. Probably the Lewis acid-base interaction between the Lewis acid moiety and the aminocarbonyl group or the sp2-hybridized N atom accelerates the reaction and controls the site-selectivity.

Journal of the American Chemical Society published new progress about Benzamides Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 329214-79-1 belongs to class pyridine-derivatives, and the molecular formula is C11H16BNO2, Category: pyridine-derivatives.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Dong, Yuman; Liu, Peng published the artcile< Amphiphilic Triblock Copolymer Prodrug for Tumor-Specific pH/Reduction Dual-Triggered Drug Delivery: Effect of Self-Assembly Behaviors>, SDS of cas: 2127-03-9, the main research area is amphiphilic triblock copolymer prodrug tumor treatment drug delivery system.

Diblock copolymer-based prodrugs have been widely designed for tumor treatment after self-assembly; however, premature drug leakage could not be ignored because their hydrophobic prodrug cores were directly exposed to the media. Here, an amphiphilic triblock copolymer prodrug with a hydrophilic PEG block, a pH-sensitive poly(2-(diisopropylamino)ethyl methacrylate) (PDPA) block, and a hydrophobic reduction-cleavable prodrug block was synthesized for tumor-specific pH/reduction dual-triggered drug delivery, via the successive RAFT polymerization of DPA and a DOX-based monomer (MAL-DOX) with a PEG-based macro-CTA. The core-shell and core-shell-corona nanoparticles could be obtained by one-step and two-step self-assembly. With the pH-sensitive gatekeeper formed by the PDPA block, the core-shell-corona nanoparticles possessed a smaller diameter with narrow distribution and better drug release with lower drug leakage. MTT assays demonstrated the selective cytotoxicity of the core-shell-corona nanoparticles to the cancer cells was dose-dependent because of the reduction-cleavable prodrug. The negligible drug leakage and selective cytotoxicity to cancer cells endow the proposed core-shell-corona prodrug nanoparticles with promising potential for tumor treatment without toxic side effects on the normal cells.

Langmuir published new progress about Antitumor agents. 2127-03-9 belongs to class pyridine-derivatives, and the molecular formula is C10H8N2S2, SDS of cas: 2127-03-9.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem