- Structural Insights into the TES/TFA Reduction of Differently Substituted Benzofurans: Dihydrobenzofurans or Bibenzyls?
-
Various polysubstituted benzofurans were reduced by using triethylsilane in trifluoracetic acid. 2,3-Dihydrobenzofurans or bibenzyl compounds were obtained in high yields, depending on the nature of the substituents at C2 and on the benzene ring of the co
- D'Orsi, Rosarita,Caivano, Ilaria,Funicello, Maria,Lupattelli, Paolo,Chiummiento, Lucia
-
supporting information
p. 63 - 64
(2020/11/04)
-
- Boron insertion into alkyl ether bonds via zinc/nickel tandem catalysis
-
Mild methods to cleave the carbon-oxygen (C?O) bond in alkyl ethers could simplify chemical syntheses through the elaboration of these robust, readily available precursors. Here we report that dibromoboranes react with alkyl ethers in the presence of a nickel catalyst and zinc reductant to insert boron into the C?O bond. Subsequent reactivity can effect oxygen-to-nitrogen substitution or one-carbon homologation of cyclic ethers and more broadly streamline preparation of bioactive compounds. Mechanistic studies reveal a cleavage-then-rebound pathway via zinc/nickel tandem catalysis.
- Lyu, Hairong,Kevlishvili, Ilia,Yu, Xuan,Liu, Peng,Dong, Guangbin
-
-
- Preparation method of ortho-alkylphenol
-
The invention relates to a preparation method of ortho-alkylphenol. A 2-(2-alkylphenoxy) pyridine derivative is used as a raw material to prepare the ortho-alkylphenol. The reaction process includes:directly adding the 2-(2-alkylphenoxy) pyridine derivati
- -
-
Paragraph 0008; 0010
(2019/01/14)
-
- Preparation methods of 2-phenethyl phenol derivative and intermediate of 2-phenethyl phenol derivative as well as intermediate
-
The invention discloses a preparation method of a 2-phenethyl phenol derivative. The preparation method of the 2-phenethyl phenol derivative comprises following steps: a compound represented in a formula 5 is subjected to a reduction reaction, a compound represented in a formula 1 is prepared, wherein the compound represented in the formula 5 is prepared from a compound represented in a formula 4 through an ester hydrolysis reaction and a decarboxylic reaction, the compound represented in the formula 4 is prepared from a compound represented in a formula 2 and a compound represented in a formula 3 through a condensation reaction, and R is hydrogen, halogen, C1-C3 alkyl or C1-C3 alkoxy. The preparation methods of the 2-phenethyl phenol derivative and an intermediate of the 2-phenethyl phenol derivative are low in cost and safe to operate, the steps and the after-treatment are simple, a few by-products are produced, the intermediate product and the final product are both easy to purify, the total yield and the purity are higher, and industrial production is facilitated.
- -
-
-
- Naturally occurring Batatasins and their derivatives as α-glucosidase inhibitors
-
Batatasins are endogenous plant hormones found in yams and other related plant species. These plants are widely consumed as botanical dietary supplements in many parts of the world. This study investigated the inhibitory effects and mechanisms of Batatasin I, III, IV, V against α-glucosidase regarding their antidiabetic activities. The results revealed that Batatasin I, III, IV inhibited α-glucosidase in a reversible and noncompetitive manner, with IC50 values of 2.55, 1.89 and 2.52 mM respectively, while Batatasin V completely abolished its inhibitory activity even at the highest concentrations tested. Furthermore, a class of Batatasin-derived compounds with different substitution patterns was synthesized and subjected to the assay to clarify the structure-activity relationships, which suggested that the hydroxyl at the C-2′ position may play a significant role in improving the inhibitory activities. Their probable binding modes and the specificity of the binding sites were studied using molecule docking simulation. It was concluded that Batatasins, especially Batatasin III and IV, are promising α-glucosidase inhibitors, which therefore could be used as functional food to alleviate postprandial hyperglycemia and as potential candidates for the development of antidiabetic agents.
- Hu, Wei-Ping,Cao, Guo-Dong,Zhu, Jin-Hua,Li, Jia-Zhong,Liu, Xiu-Hua
-
p. 82153 - 82158
(2015/10/12)
-
- Efficient heterogeneously palladium-catalysed synthesis of stilbenes and bibenzyls
-
An alternative heterogeneously palladium catalysed procedure for the synthesis of functional stilbenes and bibenzyls is reported. Starting from aryl bromides and using simple commercially available Pd/C catalyst at a low catalytic rate (1 mol%), stilbenes are obtained with 30-100% GC-yields and bibenzyls are produced in a one-pot fashion with 27-100% GC-yields. The procedure showed, however, some limitations when applied to strongly deactivated aryl bromides that could be in some extent overcome by using corresponding iodo derivatives.
- Cusati, Giuseppe,Wedig, Anja,Djakovitch, Laurent
-
scheme or table
p. 77 - 81
(2010/04/23)
-
- Arylmethyloxyphenyl derivatives: Small molecules displaying P-glycoprotein inhibition
-
Some arylmethyloxyphenyl derivatives were prepared as simplified structures of analogous arylpiperazines with high affinity toward dopaminergic D 2 and serotonergic 5-HT1A receptors and inhibiting P-glycoprotein (P-gp). The compounds 5b and 8b displayed good P-gp inhibition activity measured as [3H]vinblastine transport inhibition in the Caco-2 cell monolayer and intracellular doxorubicin accumulation in MCF7/Adr cells by flow cytometry. Compounds 5b and 8b also inhibited, dose-dependently, ATP-ase activation induced by P-gp substrate vinblastine.
- Colabufo, Nicola Antonio,Berardi, Francesco,Perrone, Roberto,Rapposelli, Simona,Digiacomo, Maria,Balsamo, Aldo
-
p. 6607 - 6613
(2007/10/03)
-
- Chromium- and tungsten-triggered valence isomerism of cis-1-acyl-2-ethynylcyclopropanes via [3,3] sigmatropy of (2-acylcyclopropyl)vinylidene - Metal intermediates
-
The reaction of cis vicinal acetylethynylcyclopropanes 1 with a catalytic amount of M(CO)5(THF) (M = Cr or W) in the presence of Et3N at room temperature gave ortho-substituted phenols 7 in good yields as valence isomerized products. In the absence of Et3N the reactions did not work at all. The reaction of a cyclopropane having an ester or an amide instead of an acetyl moiety with M(CO)5(THF) did not take place, whereas an ethynylvinylcyclopropane gave a mixture of 1- and 2-substituted 1,3,5-cycloheptatrienes. These valence isomerization reactions are assumed to proceed via the formation of vinylidene-metal intermediates 2 from terminal alkynyl moieties followed by [3,3]sigmatropy of 2 to give seven-membered carbene complexes 3. Copyright
- Ohe, Kouichi,Yokoi, Tomomi,Miki, Koji,Nishino, Fumiaki,Uemura, Sakae
-
p. 526 - 527
(2007/10/03)
-
- Palladium-promoted arylation of functionalised organolithium compounds via their zinc derivatives
-
The reaction of different functionalised organolithium compounds 2, 5, 8, and 13 [easily prepared by DTBB-catalysed lithiation of isochromane (1), phthalane (4), 2,3-dihydrobenzofuran (7) and 1-chloro-3,3-diethoxypropane (12), respectively] with an equimo
- Yus, Miguel,Gomis, Joaquin
-
p. 1989 - 1995
(2007/10/03)
-
- Negishi cross-coupling with functionalised organozinc compounds prepared by lithium-zinc transmetallation
-
The reaction of some functionalised organolithium compounds 2 (easily prepared by DTBB-catalysed lithiation of isochroman, phthalan and 2,3-dihydrobenzofuran) with an equimolecular amount of zinc bromide followed by reaction with an aryl or alkenyl bromide in the presence of a catalytic amount of Pd(PPh3)4 or Pd(PPh3)2(OAc)2 (5 mol%) under THF reflux overnight gave the expected cross-coupling compounds. These arylation or alkenylation processes, which work also with iodinated substrates, are not possible in the absence of the zinc or palladium compounds under the same reaction conditions.
- Yus, Miguel,Gomis, Joaquín
-
p. 5721 - 5724
(2007/10/03)
-
- Flash vacuum pyrolysis of methoxy-substituted lignin model compounds
-
The flash vacuum pyrolysis (FVP) of methoxy-substituted fi-O-4 lignin model compounds has been studied at 500 °C to provide mechanistic insight into the primary reaction pathways that occur under conditions of fast pyrolysis. FVP of PhCH2CH2OPh (PPE), a model of the dominant β-O-4 linkage in lignin, proceeds by C-O and C-C cleavage, in a 37:1 ratio, to produce styrene plus phenol as the dominant products and minor amounts of toluene, bibenzyl, and benzaldehyde. From the deuterium isotope effect in the FVP of PhCD2CH2OPh, it was shown that C-O cleavage occurs by homolysis and by 1,2- elimination in a ratio of 1.4:1, respectively. Methoxy substituents enhance the homolysis of the β-O-4 linkage, relative to PPE, in o-CH3O- C6H4OCH2CH2Ph (o-CH3O-PPE) and (o-CH3O)2-C6H3OCH2CH2Ph ((o- CH3O)2-PPE) by a factor of 7.4 and 21, respectively. The methoxy- substituted phenoxy radicals undergo a complex series of reactions, which are dominated by 1,5-, 1,6-, and 1,4-intramolecular hydrogen abstraction, rearrangement, and α-scission reactions. In the FVP of o-CH3O-PPE, the dominant product, salicylaldehyde, forms from the methoxyphenoxy radical by a 1,5-hydrogen shift to form 2-hydroxyphenoxymethyl radical, 1,2-phenyl shift, and β-scission of a hydrogen atom. The 2-hydroxyphenoxymethyl radical can also cleave to form formaldehyde and phenol in which the ratio of 1,2-phenyl shift to β-scission is ca. 4:1. In the FVP of o-CH3O-PPE and (o-CH3O)2- PPE, products (ca. 20 mol %) are also formed by C-O homolysis of the methoxy group. The resulting phenoxy radicals undergo 1,5- and 1,6-hydrogen shifts in a ratio of ca. 2:1 to the aliphatic or benzylic carbon, respectively, of the phenethyl chain. In the FVP of (o-CH3O)2-PPE, o-cresol was the dominant product. It was formed by decomposition of 2-hydroxy-3- hydroxymethylbenzaldehyde and 2-hydroxybenzyl alcohol, which are formed from a complex series of reactions from the 2,6-dimethoxyphenoxy radical. The key step in this reaction sequence was the rapid 1,5-hydrogen shift from 2- hydroxy-3-methoxybenzyloxy radical to 2-hydroxymethyl-6-methoxyphenoxy radical before β-scission of a hydrogen atom to give the substituted benzaldehyde. The 2-hydroxybenzyl alcohols rapidly decompose under the reaction conditions to o-benzoquinone methide and pick up hydrogen from the reactor walls to form o-cresol.
- Britt, Phillip F.,Buchanan III,Cooney, Mark J.,Martineau, Dan R.
-
p. 1376 - 1389
(2007/10/03)
-
- ALPHA-OMEGA-DIARYLALKANE COMPOUNDS SEROTONIN-2 RECEPTOR AGONISTS
-
Compounds of formula (I): STR1 [wherein: R 1 is aryl; R 2 is hydrogen, alkyl, alkoxy, halogen or cyano; R 3 is a group of formula--B--NR 4 R 5, where R 4 and R 5 are independently hydrogen, alkyl or substituted alkyl or R 4 and R 5, together with the nitr
- -
-
-
- Syntheses and Platelet Aggregation Inhibitory and Antithrombotic Properties of ethyl>benzenes
-
A series of ethyl>benzene derivatives were synthesized and evaluated for their ability to inhibit collagen-induced platelet aggregation in vitro and to protect experimantal thrombosis in mice.The results showed that the compounds were in vitro inhibitors of collagen-induced platelet aggregation.Most of them were also effective in the mouse antithrombotic assay.The compounds were found to be potent antagonists to S2 serotonergic receptor, and good correlation (r = 0.85) between their S2 serotonergic receptor antagonism and their potency as platelet antiaggregatory drugs was observed.Among the compounds studied, monophenoxy>methyl>ethyl>succinate hydrochloride (12b, MCI-9042) was selected for further pharmacological and toxicological evaluation.
- Kikumoto, Ryoji,Hara, Hiroto,Ninomiya, Kunihiro,Osakabe, Masanori,Sugano, Mamoru,et al.
-
p. 1818 - 1823
(2007/10/02)
-
- ortho-Specific alkylation of phenols via 1,3,2-benzodioxaborins
-
Reaction of a phenol with an aldehyde in the presence of phenylboronic acid gives a 1,3,2-benzodioxaborin.The latter could be reduced to the corresponding ortho-alkylphenol with tert-butylamine borane in the presence of aluminum chloride.Alternatively, the dioxaborin, when reacted with an alkylthiol or an alcohol in the presence of an acid, gave the corresponding ortho-alkylthiomethyl- or ortho-alkoxymethylphenol.Key words: phenol, alkylation, ortho-specific, 1,3,2-benzodioxaborin.
- Lau, Cheuk K.,Williams, Haydn W. R.,Tardiff, Sylvie,Dufresne, Claude,Scheigetz, John,Belanger, Patrice C.
-
p. 1384 - 1387
(2007/10/02)
-
- Carbon-Hydrogen vs. Carbon-Carbon Bond Cleavage of 1,2-Diarylethane Radical Cations in Acetonitrile-Water
-
Radical cations of 1,2-diarylethanes and 1-phenyl-2-arylethanes (Ar = phenyl, p-tolyl, p-anisyl) were generated in acidic 70percent acetonitrile-water by Cu2+-catalyzed peroxydisulfate oxidation.The radical cations fragment mainly by loss of benzylic protons (C-H cleavage) rather than by alkyl C-C bond cleavage.The radical cation of 2,3-dimethyl-2,3-diphenylbutane fragments efficiently by C-C cleavage, forming cumyl radical and cumyl cation.Oxidations of bibenzyl-bicumyl mixtures show selective oxidation of bicumyl dependent on total substrate concentration, providing evidence of equilibrating radical cations and showing that bicumyl fragments faster than bibenzyl loses protons.The effects of reaction conditions and substrate structure on reactivity are discussed.
- Camaioni, Donald M.,Franz, James A.
-
p. 1607 - 1613
(2007/10/02)
-