Month: December 2022

Khan, Jabir published the artcileLambert Salt-Initiated Development of Friedel-Crafts Reaction on Isatin to Access Distinct Derivatives of Oxindoles, Name: 1,2-Dimethoxybenzene, the publication is Journal of Organic Chemistry (2021), 86(24), 17833-17847, database is CAplus and MEDLINE.

Herein, a mild metal-free and efficacious route for the synthesis of biol. important 3-aryl oxindole derivatives I [R = H, OH, 4-MeOC₆H₄, etc.; R¹ = H, Me, Br, etc.; R² = H, NO₂, Cl; R³ = H, Me, Bn, Ts; Ar = 4-HOC₆H₄, 2,4,6-tri-MeOC₆H₂, 1H-indol-3-yl, etc.] was described. Using Lambert salt-initiated hydroarylation of isatin, a diverse array of monoarylated products, sym./unsym. double-arylated products and deoxygenated hydroarylated products could be synthesized from the single starting substrate in good to excellent yields. A preliminary mechanistic study revealed that the reaction proceeded via a monoarylated product followed by a nucleophilic attack by another electron-rich arene nucleophile under mild conditions. The potential of newly synthesized sym./unsym. 3,3-disubstituted oxindole, 3-substituted 3-hydroxy oxindoles, 3,3-di(indolyl)indolin-2-ones, and α-aryl oxindoles as valuable building blocks was further illustrated.

Journal of Organic Chemistry published new progress about 91-16-7. 91-16-7 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether,Inhibitor,Inhibitor,Inhibitor, name is 1,2-Dimethoxybenzene, and the molecular formula is C8H10O2, Name: 1,2-Dimethoxybenzene.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Xu, Jianyu published the artcileNickel-Catalyzed Deaminative Cyanation: Nitriles and One-Carbon Homologation from Alkyl Amines, Category: ethers-buliding-blocks, the publication is Organic Letters (2021), 23(16), 6242-6245, database is CAplus and MEDLINE.

A nickel-catalyzed deaminative cyanation of Katritzky pyridinium salts was developed. When it was coupled with formation of the pyridinium salt from primary amines, this method enabled alkyl amines to be converted to alkyl nitriles. A less toxic cyanide reagent, Zn(CN)₂, was utilized, and diverse functional groups and heterocycles were tolerated. The method also enabled a one-carbon homologation of alkyl amines via reduction of the nitrile products, in addition to many other potential transformations of the versatile nitrile group.

Organic Letters published new progress about 6850-57-3. 6850-57-3 belongs to ethers-buliding-blocks, auxiliary class Amine,Benzene,Ether, name is (2-Methoxyphenyl)methanamine, and the molecular formula is C15H21BO3, Category: ethers-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Marcucci, Eleonora published the artcileSolid-Phase Synthesis of NMe-IB-01212, a Highly N-Methylated Cyclic Peptide, Related Products of ethers-buliding-blocks, the publication is Organic Letters (2012), 14(2), 612-615, database is CAplus and MEDLINE.

N-Methylation of peptides is an important synthetic tool in peptide-based medicinal chem. Herein, an optimized strategy for solid-phase synthesis of small but highly N-methylated cyclic peptides is described. The proposed route addresses several problems associated with the synthesis of peptides containing several sequential N-methyl-amino acids, such as in situ N-methylation, difficulty of acylation, epimerization, diketopiperazine formation, and stability at the NMe sites under trifluoroacetic acid exposure. The resulting NMe-IB-01212 exhibits micromolar activity and considerable stability.

Organic Letters published new progress about 77128-73-5. 77128-73-5 belongs to ethers-buliding-blocks, auxiliary class Inhibitor, name is (S)-2-((((9H-Fluoren-9-yl)methoxy)carbonyl)(methyl)amino)-3-phenylpropanoic acid, and the molecular formula is C25H23NO4, Related Products of ethers-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Cain, Caitlin N. published the artcileTile-Based Pairwise Analysis of GC x GC-TOFMS Data to Facilitate Analyte Discovery and Mass Spectrum Purification, Computed Properties of 91-16-7, the publication is Analytical Chemistry (Washington, DC, United States) (2022), 94(14), 5658-5666, database is CAplus and MEDLINE.

A new tile-based pairwise anal. workflow, termed 1v1 anal., is presented to discover and identify analytes that differentiate two chromatograms collected using comprehensive two-dimensional (2D) gas chromatog. coupled with time-of-flight mass spectrometry (GC x GC-TOFMS). Tile-based 1v1 anal. easily discovered all 18 non-native analytes spiked in diesel fuel within the top 30 hits, outperforming standard pairwise chromatog. analyses. However, eight spiked analytes could not be identified with multivariate curve resolution-alternating least-squares (MCR-ALS) nor parallel factor anal. (PARAFAC) due to background contamination. Analyte identification was achieved with class comparison enabled-mass spectrum purification (CCE-MSP), which obtains a pure analyte spectrum by normalizing the spectra to an interferent mass channel (m/z) identified from 1v1 anal. and subtracting the two spectra. This report also details the development of CCE-MSP assisted MCR-ALS, which removes the identified interferent m/z from the data prior to decomposition In total, 17 out of 18 spiked analytes had a match value (MV) > 800 with both versions of CCE-MSP. For example, MCR-ALS and PARAFAC were unable to decompose the pure spectrum of Me decanoate (MVs < 200) due to its low 2D chromatog. resolution (~0.34) and high interferent-to-analyte signal ratio (~30:1). By leveraging information gained from 1v1 anal., CCE-MSP and CCE-MSP assisted MCR-ALS obtained a pure spectrum with an average MV of 908 and 964, resp. Furthermore, tile-based 1v1 anal. was applied to track moisture damage in cacao beans, where 86 analytes with at least a 2-fold concentration change were discovered between the unmolded and molded samples. This 1v1 anal. workflow is beneficial for studies where multiple replicates are either unavailable or undesirable to save anal. time.

Analytical Chemistry (Washington, DC, United States) published new progress about 91-16-7. 91-16-7 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether,Inhibitor,Inhibitor,Inhibitor, name is 1,2-Dimethoxybenzene, and the molecular formula is C8H10O2, Computed Properties of 91-16-7.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Terwilliger, Daniel W. published the artcileSelective Synthesis of Divergolide I, Recommanded Product: (+)-B-Methoxydiisopinocampheylborane, the publication is Journal of the American Chemical Society (2018), 140(8), 2748-2751, database is CAplus and MEDLINE.

Divergolide I (I) is a naphthoquinone ansamycin that exhibits broad antibacterial activity. Its tetracyclic ring system is believed to be biosynthetically assembled via ring-contraction of a macrocyclic precursor (proto-divergolide) that is both a macrolactone and a macrolactam. We here report a convergent and enantioselective synthesis that delivers the target mol. in less than 20 linear steps. Our work establishes the absolute configuration of divergolide I, confirms its relative configuration, and demonstrates that the biomimetic cyclization of a proto-divergolide can be surprisingly selective.

Journal of the American Chemical Society published new progress about 99438-28-5. 99438-28-5 belongs to ethers-buliding-blocks, auxiliary class Chiral,Aliphatic cyclic hydrocarbon, name is (+)-B-Methoxydiisopinocampheylborane, and the molecular formula is C7H7BrN2O2, Recommanded Product: (+)-B-Methoxydiisopinocampheylborane.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Hullar, Ted published the artcileEnhanced photodegradation of dimethoxybenzene isomers in/on ice compared to in aqueous solution, Recommanded Product: 1,2-Dimethoxybenzene, the publication is Atmospheric Chemistry and Physics (2022), 22(9), 5943-5959, database is CAplus.

Photochem. reactions of contaminants in snow and ice can be important sinks for organic and inorganic compounds deposited onto snow from the atm. and sources for photoproducts released from snowpacks into the atm. Snow contaminants can be found in the bulk ice matrix, in internal liquid-like regions (LLRs), or in quasi-liquid layers (QLLs) at the air-ice interface, where they can readily exchange with the firn air. Some studies have reported that direct photochem. reactions occur faster in LLRs and QLLs than in aqueous solution, while others have found similar rates. Here, we measure the photodegradation rate constants for loss of the three dimethoxybenzene isomers under varying exptl. conditions, including in aqueous solution, in LLRs, and at the air-ice interface of nature-identical snow. Relative to aqueous solution, we find modest photodegradation enhancements (3- and 6-fold) in LLRs for two of the isomers and larger enhancements (15- to 30-fold) at the air-ice interface for all three isomers. We use computational modeling to assess the impact of light absorbance changes on photodegradation rate enhancements at the interface. We find small (2-5 nm) bathochromic (red) absorbance shifts at the interface relative to in solution, which increases light absorption, but this factor only accounts for less than 50% of the measured rate constant enhancements. The major factor responsible for photodegradation rate enhancements at the air-ice interface appears to be more efficient photodecay: estimated dimethoxybenzene quantum yields are 6- to 24-fold larger at the interface compared to in aqueous solution and account for the majority (51%-96%) of the observed enhancements. Using a hypothetical model compound with an assumed Gaussian-shaped absorbance peak, we find that a shift in the peak to higher or lower wavelengths can have a minor to substantial impact on photodecay rate constants, depending on the original location of the peak and the magnitude of the shift. Changes in other peak properties at the air-ice interface, such as peak width and height (i.e., molar absorption coefficient), can also impact rates of light absorption and direct photodecay. Our results suggest our current understanding of photodegradation processes underestimates the rate at which some compounds are broken down, as well as the release of photoproducts into the atm.

Atmospheric Chemistry and Physics published new progress about 91-16-7. 91-16-7 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether,Inhibitor,Inhibitor,Inhibitor, name is 1,2-Dimethoxybenzene, and the molecular formula is C8H10O2, Recommanded Product: 1,2-Dimethoxybenzene.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Rivero-Crespo, Miguel A. published the artcilePreparation of Recyclable and Versatile Porous Poly(aryl thioether)s by Reversible Pd-Catalyzed C-S/C-S Metathesis, Computed Properties of 93-04-9, the publication is Journal of the American Chemical Society (2021), 143(50), 21331-21339, database is CAplus and MEDLINE.

Porous organic materials (polymers and COFs) have shown a number of promising properties; however, the lability of their linkages often limits their robustness and can hamper downstream industrial application. Inspired by the outstanding chem., mech. and thermal resistance of the 1D polymer polyphenylene sulfide (PPS), we have designed a new family of porous poly arylthioethers, synthesized via a mild Pd-catalyzed C-S/C-S metathesis-based method, that merges the attractive features common to porous polymers and PPS in a single material. In addition, the method is highly modular, allowing to easily introduce application-oriented functionalities in the materials for a series of environmentally relevant applications including metal capture, metal sensing and heterogeneous catalysis. Moreover, despite their extreme chem. resistance, the polymers can be easily recycled to recover the original monomers, offering an attractive perspective for their sustainable use. In a broader context, these results clearly demonstrate the untapped potential of emerging single-bond metathesis reactions in the preparation of new, recyclable materials.

Journal of the American Chemical Society published new progress about 93-04-9. 93-04-9 belongs to ethers-buliding-blocks, auxiliary class Naphthalene,Ether, name is 2-Methoxynaphthalene, and the molecular formula is C11H10O, Computed Properties of 93-04-9.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Bole, Leonie J. published the artcileEnhancing Metalating Efficiency of the Sodium Amide NaTMP in Arene Borylation Applications, Formula: C11H10O, the publication is Angewandte Chemie, International Edition (2022), 61(26), e202204262, database is CAplus and MEDLINE.

Though LiTMP (TMP = 2,2,6,6-tetramethylpiperidide) is a commonly used amide, surprisingly the heavier NaTMP has hardly been utilized. Here, by mixing NaTMP with tridentate donor PMDETA (N,N,N’,N”,N”-pentamethyldiethylenetriamine), we provide structural, and mechanistic insights into the sodiation of non-activated arenes (e.g. anisole and benzene). While these reactions are low yielding, adding B(OiPr)₃ has a profound effect, not only by intercepting the C_Ar-Na bond, but also by driving the metalation reaction towards quant. formation of more stabilized sodium aryl boronates. Demonstrating its metalating power, regioselective C2-metalation/borylation of naphthalene has been accomplished contrasting with single-metal based protocols which are unselective and low yielding. Extension to other arenes allows for in situ generation of aryl boronates which can then directly engage in Suzuki-Miyaura couplings, furnishing a range of biaryls in a selective and efficient manner.

Angewandte Chemie, International Edition published new progress about 93-04-9. 93-04-9 belongs to ethers-buliding-blocks, auxiliary class Naphthalene,Ether, name is 2-Methoxynaphthalene, and the molecular formula is C11H10O, Formula: C11H10O.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Bole, Leonie J. published the artcileEnhancing Metalating Efficiency of the Sodium Amide NaTMP in Arene Borylation Applications, HPLC of Formula: 91-16-7, the publication is Angewandte Chemie, International Edition (2022), 61(26), e202204262, database is CAplus and MEDLINE.

Though LiTMP (TMP = 2,2,6,6-tetramethylpiperidide) is a commonly used amide, surprisingly the heavier NaTMP has hardly been utilized. Here, by mixing NaTMP with tridentate donor PMDETA (N,N,N’,N”,N”-pentamethyldiethylenetriamine), we provide structural, and mechanistic insights into the sodiation of non-activated arenes (e.g. anisole and benzene). While these reactions are low yielding, adding B(OiPr)₃ has a profound effect, not only by intercepting the C_Ar-Na bond, but also by driving the metalation reaction towards quant. formation of more stabilized sodium aryl boronates. Demonstrating its metalating power, regioselective C2-metalation/borylation of naphthalene has been accomplished contrasting with single-metal based protocols which are unselective and low yielding. Extension to other arenes allows for in situ generation of aryl boronates which can then directly engage in Suzuki-Miyaura couplings, furnishing a range of biaryls in a selective and efficient manner.

Angewandte Chemie, International Edition published new progress about 91-16-7. 91-16-7 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether,Inhibitor,Inhibitor,Inhibitor, name is 1,2-Dimethoxybenzene, and the molecular formula is C8H10O2, HPLC of Formula: 91-16-7.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Furukawa, Takayuki published the artcileC-H Functionalization at Sterically Congested Positions by the Platinum-Catalyzed Borylation of Arenes, Synthetic Route of 596819-12-4, the publication is Journal of the American Chemical Society (2015), 137(38), 12211-12214, database is CAplus and MEDLINE.

Despite significant progress in the area of C-H bond functionalization of arenes, no general method is reported for the functionalization of C-H bonds at the sterically encumbered positions of simple arenes, such as mesitylene. Herein, the authors report the development of the 1st Pt-based catalyst for C-H borylation of arenes and heteroarenes. Notably, this method exhibited high tolerance toward steric hindrance and provided rapid access to 2,6-disubstituted phenylboronic esters, valuable building blocks for further elaborations.

Journal of the American Chemical Society published new progress about 596819-12-4. 596819-12-4 belongs to ethers-buliding-blocks, auxiliary class Thiophene,Boronic acid and ester,Ether,Boronate Esters,Boronic acid and ester, name is 2-(5-Methoxythiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, and the molecular formula is C11H17BO3S, Synthetic Route of 596819-12-4.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem