Tag: M.W=250-300

Collier, Willard E. published the artcileAlkaline hydrolysis of nonphenolic β-O-4 lignin model dimers. Further studies of the substituent effect on the leaving phenoxide, Recommanded Product: 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol, the publication is Holzforschung (1996), 50(5), 420-424, database is CAplus.

Reaction rates and activation parameters for the alk. hydrolysis of nonphenolic β-O-4 lignin models [2-(4-substituted-phenoxy)-1-(3,4-dimethoxyphenyl)ethanol] were compared to 2-methoxylated B-ring analogs run earlier. The Hammett plot with the best fit used σ^– values to give a ρ of 1.9 ± 0.2, while the 2-methoxyl-substituted compounds had a ρ of 2.3 ± 0.3. Compounds with a methoxyl group at the ortho position of the leaving phenoxide ion hydrolyzed slightly faster than the nonmethoxylated analogs, indicating that the 2-methoxy group is a weak electron withdrawer. The strong electron-withdrawing 4-CHO and 4-CF₃ substituents gave significantly different activation parameters than the unsubstituted compound Experiments with O-labeled water suggested that the earlier proposed S_NAr mechanism for the alk. hydrolysis of strong electron-withdrawing compounds is not correct. It appears that all nonphenolic β-O-4 dimers are hydrolyzed by a neighboring group mechanism.

Holzforschung published new progress about 183303-74-4. 183303-74-4 belongs to ethers-buliding-blocks, auxiliary class Benzene,Alcohol,Ether, name is 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol, and the molecular formula is C16H18O4, Recommanded Product: 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol.

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

Baciocchi, Enrico published the artcileLignin peroxidase-catalyzed oxidation of nonphenolic trimeric lignin model compounds: Fragmentation reactions in the intermediate radical cations, Application In Synthesis of 183303-74-4, the publication is Journal of Organic Chemistry (2003), 68(23), 9061-9069, database is CAplus and MEDLINE.

The H₂O₂-promoted oxidations of the two nonphenolic β-O-aryl lignin model trimers 1 and 2, catalyzed by lignin peroxidase (LiP) at pH = 3.5, have been studied. The results have been compared with those obtained in the oxidation of 1 and 2 with the genuine one-electron oxidant potassium 12-tungstocobalt(III)ate. These models present a different substitution pattern of the three aromatic rings, and by one-electron oxidation, they form radical cations with the pos. charge, which is localized in the dialkoxylated ring as also evidenced by a pulse radiolysis study. Both the oxidations with the enzymic and with the chem. systems lead to the formation of products deriving from the cleavage of C-C and C-H bonds in a β position with respect to the radical cation with the charge residing in the dialkoxylated ring (3,4-dimethoxybenzaldehyde (5) and a trimeric ketone 6 in the oxidation of 1 and a dimeric aldehyde 8 and a trimeric ketone 9 in the oxidation of 2). These products are accompanied by a dimeric aldehyde 7 in the oxidation of 1 and 4-methoxybenzaldehyde (10) in the oxidation of 2. The unexpected formation of these two products has been explained by suggesting that 1^â€? and 2^â€? can also undergo an intramol. electron transfer leading to the radical cations 1a^â€? and 2a^â€? with the charge residing in a monoalkoxylated ring. The fast cleavage of a C-C bond β to this ring, leading to 7 from 1^â€? and to 10 from 2^â€?, is the driving force of the endoergonic electron transfer. A kinetic steady-state investigation of the LiP-catalyzed oxidation of the trimer 2, the dimeric model 1-(3,4-dimethoxyphenyl)-2-phenoxy-1-ethanol (4), and 3,4-dimethoxybenzyl alc. (3) has indicated that the turnover number (k_cat) and the affinity for the enzyme decrease significantly by increasing the size of the model compound In contrast, the three substrates exhibited a very similar reactivity toward a chem. oxidant [Co^IIIW]. This suggests a size-dependent interaction of the enzyme with the substrate which may influence the efficiency of the electron transfer.

Journal of Organic Chemistry published new progress about 183303-74-4. 183303-74-4 belongs to ethers-buliding-blocks, auxiliary class Benzene,Alcohol,Ether, name is 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol, and the molecular formula is C16H18O4, Application In Synthesis of 183303-74-4.

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

Galkin, Maxim V. published the artcileMild and Robust Redox-Neutral Pd/C-Catalyzed Lignol β-O-4′ Bond Cleavage Through a Low-Energy-Barrier Pathway, Safety of 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol, the publication is ChemSusChem (2015), 8(13), 2187-2192, database is CAplus and MEDLINE.

A Pd/C catalyzed redox neutral C-O bond cleavage of 2-aryloxy-1-arylethanols has been developed. The reactions are carried out at 80 °C, in air, using a green solvent system to yield the aryl ketones in near quant. yields. Addition of catalytic amounts of a hydrogen source to the reaction mixture activates the catalyst to proceed through a low energy barrier pathway. Initial studies support a transfer hydrogenolysis reaction mechanism that proceeds through an initial dehydrogenation followed by an enol adsorption to Pd/C and a reductive C-O bond cleavage.

ChemSusChem published new progress about 183303-74-4. 183303-74-4 belongs to ethers-buliding-blocks, auxiliary class Benzene,Alcohol,Ether, name is 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol, and the molecular formula is C16H18O4, Safety of 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol.

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

Lanier, Marion published the artcileRepurposing Suzuki Coupling Reagents as a Directed Fragment Library Targeting Serine Hydrolases and Related Enzymes, Safety of (2-((3-Chlorobenzyl)oxy)phenyl)boronic acid, the publication is Journal of Medicinal Chemistry (2017), 60(12), 5209-5215, database is CAplus and MEDLINE.

Serine hydrolases are susceptible to potent reversible inhibition by boronic acids. Large collections of chem. diverse boronic acid fragments are com. available because of their utility in coupling chem. The authors repurposed the approx. 650 boronic acid reagents in the collection as a directed fragment library targeting serine hydrolases and related enzymes. Highly efficient hits (LE > 0.6) often result. The utility of the approach is illustrated with the results against autotaxin, a phospholipase implicated in cardiovascular disease.

Journal of Medicinal Chemistry published new progress about 849062-32-4. 849062-32-4 belongs to ethers-buliding-blocks, auxiliary class Chloride,Boronic acid and ester,Benzene,Ether,Boronic Acids,Boronic Acids,Boronic acid and ester,, name is (2-((3-Chlorobenzyl)oxy)phenyl)boronic acid, and the molecular formula is C13H12BClO3, Safety of (2-((3-Chlorobenzyl)oxy)phenyl)boronic acid.

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

Sun, Kangkang published the artcileCobalt Nanoparticles Embedded in N-Doped Porous Carbon Derived from Bimetallic Zeolitic Imidazolate Frameworks for One-Pot Selective Oxidative Depolymerization of Lignin, Category: ethers-buliding-blocks, the publication is ChemCatChem (2019), 11(4), 1264-1271, database is CAplus.

Co nanoparticles embedded in N-doped porous C (Co@CN) were prepared by the pyrolysis of bimetallic zeolitic imidazolate frameworks (BMZIFs) based on ZIF-8 and ZIF-67. The catalyst shows excellent catalytic efficiency in 1-pot selective oxidative cleavage of different linkages like β-O-4, α-O-4 and β-1 in organosolv lignin and lignin model compounds in the presence of O (ambient pressure) under mild conditions (383 K). Compared with traditional supported catalyst, the catalyst gives a highly hollow structure, which favored the adsorption of substrates and O. The uniform Co nanoparticles surrounded by N-doped graphitic structures and the strong electron transfer from graphitic N to Co NPs make it hard to be oxidized prior to use and higher catalytic reactivity. Also, the catalyst can be easily recovered by magnetic force after the reaction, and reused after reduction for 5 times without an obvious change in yields.

ChemCatChem published new progress about 183303-74-4. 183303-74-4 belongs to ethers-buliding-blocks, auxiliary class Benzene,Alcohol,Ether, name is 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol, and the molecular formula is C27H29N5O5, Category: ethers-buliding-blocks.

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

Zhang, Hai-Jun published the artcileChemoselective, Scalable Nickel-Electrocatalytic O-Arylation of Alcohols, Computed Properties of 959972-40-8, the publication is Angewandte Chemie, International Edition (2021), 60(38), 20700-20705, database is CAplus and MEDLINE.

Herein a Ni-catalyzed electrochem. driven protocol to afford aryl-alkyl ether bonds through O-arylation of alcs. was depicted. This electrochem. method did not require strong base, exogenous expensive transition metal catalysts (e.g., Ir, Ru), and could easily be scaled up in either a batch or flow setting. Interestingly, e-etherification exhibited an enhanced substrate scope over the mechanistically related photochem. variant as it tolerated tertiary amine functional groups in the alc. nucleophile. with a broad substrate scope in an operationally simple way.

Angewandte Chemie, International Edition published new progress about 959972-40-8. 959972-40-8 belongs to ethers-buliding-blocks, auxiliary class Boronic acid and ester,Benzene,Ether,Boronate Esters,Boronic Acids,Boronic acid and ester, name is 2-(4-(2-Methoxyethoxy)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, and the molecular formula is C21H24O8, Computed Properties of 959972-40-8.

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

Lui, Matthew Y. published the artcileUnravelling Some of the Key Transformations in the Hydrothermal Liquefaction of Lignin, Synthetic Route of 183303-74-4, the publication is ChemSusChem (2017), 10(10), 2140-2144, database is CAplus and MEDLINE.

Using both exptl. and computational methods, focusing on intermediates and model compounds, some of the main features of the reaction mechanisms that operate during the hydrothermal processing of lignin were elucidated. Key reaction pathways and their connection to different structural features of lignin were proposed. Under neutral conditions, subcritical water was demonstrated to act as a bifunctional acid/base catalyst for the dissection of lignin structures. In a complex web of mutually dependent interactions, guaiacyl units within lignin were shown to significantly affect overall lignin reactivity.

ChemSusChem published new progress about 183303-74-4. 183303-74-4 belongs to ethers-buliding-blocks, auxiliary class Benzene,Alcohol,Ether, name is 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol, and the molecular formula is C16H18O4, Synthetic Route of 183303-74-4.

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

Astolfi, Paola published the artcileNew mediators for the enzyme laccase: mechanistic features and selectivity in the oxidation of non-phenolic substrates, Synthetic Route of 183303-74-4, the publication is New Journal of Chemistry (2005), 29(10), 1308-1317, database is CAplus.

New mediators of laccase have been comparatively evaluated and ranked towards the benchmark aerobic oxidation of p-MeO-benzyl alc. The mechanism of oxidation of this non-phenolic substrate by each mediator, which is initially oxidized by laccase to the Med_ox form, has been assessed among three alternatives. The latter make the phenoloxidase laccase competent for the indirect oxidation of non-phenolic (and thus unnatural) substrates. Exptl. characterization of the mediators, by spectrophotometric, electrochem. and thermochem. survey, is reported. Clear-cut evidence for the formation of a benzyl radical intermediate in the oxidation of a particular benzyl alc. with laccase and a :N-OH mediator is attained by a trapping experiment The selectivity of the laccase-catalyzed oxidation of two competing lignin and polysaccharide model compounds has been assessed by using the highly proficient 4-MeO-HPI mediator, and found very high in favor of the former model. This evidence is in keeping with the operation of a radical hydrogen-abstraction process that efficiently cleaves the benzylic rather than the aliphatic C-H bond of the two models. Significant is the finding that catechol, i.e., a model of recurring phenolic structures in lignin, once oxidized to aryloxyl radical by laccase is capable to mediate a radical oxidation of non-phenolic compounds This supports a fully-fledged role of laccase as a delignifying enzyme in nature by way of no other mediators than the very phenolic groups of lignin. Finally, an evaluation of the dissociation energy of the NO-H bond of HBT, which is not accessible exptl., is provided by the use of a thermochem. cycle and theor. calculations

New Journal of Chemistry published new progress about 183303-74-4. 183303-74-4 belongs to ethers-buliding-blocks, auxiliary class Benzene,Alcohol,Ether, name is 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol, and the molecular formula is C16H18O4, Synthetic Route of 183303-74-4.

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

Baciocchi, Enrico published the artcileOxidation of non-phenolic β-O-aryl-lignin model dimers catalyzed by lignin peroxidase. Comparison with the oxidation induced by potassium 12-tungstocobalt(III)ate, HPLC of Formula: 183303-74-4, the publication is Journal of the Chemical Society, Perkin Transactions 2 (2001), 1506-1511, database is CAplus.

The H₂O₂-promoted oxidations of the non-phenolic β-O-aryl-lignin model dimers 1-(3,4-dimethoxyphenyl)-2-phenoxyethanol (I) and 2-(4-methoxyphenoxy)-1-phenylethanol (II) catalyzed by lignin peroxidase (III) at pH =4.0 were studied. The oxidation of I mainly leads to the corresponding ketone, indicating that the prevailing reaction of the intermediate radical cation I^+· is Cα-H deprotonation. The oxidation of II forms 2-(4-methoxyphenoxy)-2-phenylethanol, an isomer of II, 2-phenyl-1,4-dioxaspiro[4,5]deca-6,9-dien-8-one (IV), and products coming from the cleavage of the C-C bond γ to the more electron rich ring. The formation of all of these products can be rationalized by assuming that the main reaction of the intermediate II^+· is a nucleophilic attack of the alc. OH group on the ring bearing the pos. charge. This leads to a spirocyclohexadienyl radical, which either is then oxidized to the dioxaspirodecadienone IV or undergoes ring opening to give an alkoxyl radical from which the isomer of II and the C-C bond cleavage products may form. Support for this mechanism was provided by a study of the oxidation of 4-MeOC₆H₄OCH₂CD₂OH and by comparing the results with those obtained when the alkoxyl radical 4-MeOC₆H₄OCH₂CD₂O^· was generated from 4-MeOC₆H₄OCH₂CD₂OOt-Bu. The oxidation of I induced by the genuine one-electron oxidant K 12-tungstocobalt(III)ate (V) at pH =4.0 confirms the results obtained with III. However, under the same conditions, no fragmentation products were observed in the oxidation of II, probably because of a fast oxidation, by V, of the spirocyclohexadienyl radical.

Journal of the Chemical Society, Perkin Transactions 2 published new progress about 183303-74-4. 183303-74-4 belongs to ethers-buliding-blocks, auxiliary class Benzene,Alcohol,Ether, name is 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol, and the molecular formula is C16H18O4, HPLC of Formula: 183303-74-4.

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

Annunziatini, Claudia published the artcileAryl substituted N-hydroxyphthalimides as mediators in the laccase-catalyzed oxidation of lignin model compounds and delignification of wood pulp, Product Details of C16H18O4, the publication is Journal of Molecular Catalysis B: Enzymatic (2005), 32(3), 89-96, database is CAplus.

Aryl substituted N-hydroxyphthalimides (NHPIs) have been tested as mediators in the laccase-promoted oxidation of non-phenolic monomeric and dimeric lignin model compounds and in the delignification of kraft pulp samples. In the oxidation of the model compounds a significant increase in the product yields was observed upon increasing the electron donating properties of the NHPI ring substituent. Product yields also increased, but to a smaller extent, by increasing the electron donating properties of the aromatic substituent in the lignin models. These results suggest the contribution to the overall reactivity of both the oxidation of the aryl substituted NHPI to the N-oxyl radical (X-PINO) by laccase and the hydrogen atom transfer step from the substrate to the X-PINO, with a major contribution of the former process. When applied to the delignification of kraft pulps again the mediation efficiency increased by increasing the electron donating properties of the NHPI aryl substituent, the best mediators being 4-Me-NHPI and 4-MeO-NHPI. Thus, the use of non-phenolic lignin model compounds in the oxidation promoted by the laccase/X-NHPI system is well suited to mimic the behavior of the lignin polymer.

Journal of Molecular Catalysis B: Enzymatic published new progress about 183303-74-4. 183303-74-4 belongs to ethers-buliding-blocks, auxiliary class Benzene,Alcohol,Ether, name is 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol, and the molecular formula is C16H18O4, Product Details of C16H18O4.

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