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[Display omitted] • The enantioselective Michael addition of malonates with unsaturated ketones. • Catalyzed by samarium amide Sm[N(SiMe 3) 2 ] 3 together with the chiral phenoxy-functionalized amino alcohol proligands. • The products with good group tolerance, mostly in high to excellent yields (85–98%) and good to excellent ee values (50– >99%). • A possible mechanism was proposed. A combination of rare-earth metal amides RE[ N (SiMe 3) 2 ] 3 and chiral phenoxy-functionalized amino alcohol proligands was developed to realize the enantioselective Michael addition of malonates with unsaturated ketones. The reactions catalyzed by samarium amide Sm[ N (SiMe 3) 2 ] 3 were performed best together with the chiral proligand H 3 L1 (H 3 L1 = 2,4-di- tert -butyl-6-((((1 S ,2 R)-2-hydroxy-1,2-diphenylethyl) amino)methyl)phenol) in DCE with good group tolerance, mostly in high to excellent yields (85–98 %) and good to excellent ee values (50− >99 %). The possible mechanism was also proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • A simple metal-free strategy for the synthesis of phenols. • An azopyrazole-linked Schiff base as organocatalyst. • Use of the green solvent system for the synthesis. A simple metal-free strategy for the synthesis of phenols from aryl and hetero aryl-boronic acids using arylazopyrazole linked o -hydroxyl Schiff base has been illustrated. These sustainable ipso -hydroxylations have very short reaction times, using aqueous H 2 O 2 as the oxidant in aqueous-alcoholic medium. The current protocol has been demonstrated to be effective with a variety of electron-rich and electron-deficient aromatic substrates and provides access to a wide range of phenols. This is the first time that an azoyrazole linked Schiff base has been used to increase the nucleophilicity of H 2 O 2 , in oxidative hydroxylation reactions. [ABSTRACT FROM AUTHOR]

• Recyclable bio-polymer support for the ipso -hydroxylation of arylboronic acids. • Greener conditions; aerobic, room temperature, short reaction time and water as a solvent. • Readily available eco-friendly material; chitosan and CNT@chitosan supports. • Metal- and base-free transformation. • Satisfactory conversion to the desired products. Oxidative hydroxylation of arylboronic acids to the corresponding phenolic compounds under metal- and base-free aerobic conditions is successfully demonstrated on a biopolymer support (chitosan or chitosan immobilized onto carbon nanotubes (CNT@Chitosan)). Hydrogen peroxide, as an eco-friendly oxidant, is compatible with the biopolymer supports and provides hydroxylation products in an efficient manner. The CNT@chitosan biopolymer support is particularly interesting for its potential recyclability. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Efficient synthetic methodology for benzosuberene and dihydronaphthalene analogues. • Methodology accommodated larger scale reactions. • Palladium catalyzed amination converted phenolic analogues to aniline congeners. Abstract Benzosuberene analogues (1 and 2) and dihydronaphthalene analogues (3 and 4) function as potent inhibitors of tubulin polymerization, demonstrate pronounced cytotoxicity (low nM to pM range) against human cancer cell lines, and are promising vascular disrupting agents (VDAs). As such, these compounds represent lead anticancer agents with potential translatability towards the clinic. Methodology previously established by us (and others) facilitated synthetic access to a variety of structural and functional group modifications necessary to explore structure activity relationship considerations directed towards the development of these (and related) molecules as potential therapeutic agents. During the course of these studies it became apparent that the availability of synthetic methodology to facilitate direct conversion of the phenolic-based compounds to their corresponding aniline congeners would be beneficial. Accordingly, modified synthetic routes toward these target phenols (benzosuberene 1 and dihydronaphthalene 3) were developed in order to improve scalability and overall yield [45-57% (1) and 32% (3)]. Moreover, benzosuberene-based phenolic analogue 1 and separately dihydronaphthalene-based phenolic analogue 3 were successfully converted into their corresponding aniline analogues 2 and 4 in good yield (>60% over three steps) using a palladium catalyzed amination reaction. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • p -TsOH promoted synthesis of 4-tosyloxy-2 H -chromenes in moderate to excellent yields. • p -TsOH acts not only as a promoter in this reaction, and also as the sulfonate source. • The 4-tosyloxy-2 H -chromenes are versatile intermediates in organic synthesis. • This method can be enlarged to gram scale. Abstract A novel and efficient p -TsOH-promoted cascade cyclization of 2-propynolphenols is developed to give 4-tosyloxy-2 H -chromenes in moderate to efficient yields. It is noted that p -TsOH acts not only as a promoter in this reaction, and also as the sulfonate source. Importantly, the obtained 4-tosyloxy-2 H -chromenes can be used as versatile intermediates for the synthesis of various functionalized compounds through diverse metal-catalyzed cross-coupling reactions. Moreover, this method can be enlarged to gram scale. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Convenient heterogeneous catalytic system. • Greener conditions; recyclable and reusable catalyst in water. • Facile carbon nanotube(CNT)-chitosan nanohybrid film. • Versatile copper-catalyzed aerobic ipso -hydroxylation. • Satisfactory isolated yield of the corresponding product phenols. Abstract A convenient heterogeneous catalytic system consisting of recyclable and reusable carbon nanotube-chitosan nanohybrid film and copper salt was developed for the aerobic ipso -hydroxylation of arylboronic acids. A variety of arylboronic acids bearing electron-withdrawing or electron-donating groups were smoothly transformed at room temperature in water to afford the corresponding phenols in high yields. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Efficient strategy to access biologically important 3,3-disubstituted Oxindoles. • Excellent functional group tolerance and wide substrate scope. • Metal-free intramolecular iodocyclization to enable chromene fused spirooxindoles. • Diverse 3,3-disubstitued and chromene fused spirooxindoles in high yields. Abstract 3-Alkynyl-3-OBoc oxindoles underwent Cu(II) mediated Friedel-Crafts alkylation with indoles and phenols to yield of structurally diverse 3-alkynyl-3-indole/phenol-oxindole derivatives. The synthetic application of alkylated phenol derivatives were further demonstrated to biologically important new class of chromene fused spirooxindoles through intramolecular metal-free iodocyclization under mild reaction conditions with broad substrate scope in very good yields. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Selective biocarboxylation of substituted phenols. • Whole-cells catalyzed formation of ortho-hydroxybenzoates. • Method potential for synthesis of new lignin-derived compounds. Abstract Selective carboxylation of substituted phenols is realized in the presence of bicarbonate under ambient pressure by engineered Escherichia coli whole-cells expressing various hydroxybenzoate decarboxylases, leading to their corresponding ortho-hydroxybenzoates. This process may be further developed as an efficient route to upgrade lignin-derived phenolic compounds as valuable building blocks. [ABSTRACT FROM AUTHOR]

A novel and efficient metal-free synthesis of phenolic compounds was developed via coupling cyclization of DMF as a carbon source with active methylene compounds such as 1,3-dicarbonyl compounds with the assistance of 1,1-dichloro-2-nitroethene. The method we used was different from other traditional phenol functionalization methods. In the reaction, the 1,1-dichloro-2-nitroethene as a promoter which unlike our previous research on 1,1-dichloro-2-nitroethene. The method allows the convenient construction of phenolic compounds under mild reaction conditions and moderate yields. [ABSTRACT FROM AUTHOR]

An efficient and simple approach for the synthesis of functionalized 4 H -chromenes has been developed via acid catalyzed Michael addition of phenols to benzylidene oxobutanoates. Preliminary mechanistic studies were conducted, suggesting that intermediate chroman derivative is initially formed which on dehydration produces final 4 H -chromene. The conversion of 4 H- chromenes into linear and angular pyranocoumarins is also described. The structural arrangements between the pyran and coumarin rings have been established by X-ray crystallographic analysis and 2D NMR spectroscopy. [ABSTRACT FROM AUTHOR]

A mild and efficient method for THP protection of indazoles and benzyl alcohols has been developed in water, the most environmentally friendly solvent, in which Tween 20 (2% w/w) was added to form aqueous micelles to increase the solubility of starting materials. This aqueous protocol allowed the reaction to proceed smoothly at room temperature and with only 1.2 equiv of DHP, providing moderate to good yields of THP protected products for a wide scope of substrates. In addition, the methodology was highly practical in the large-scale synthesis (1 g synthesis of 2c as an example), wherein the convenient work-up and purification procedure (simple filtration) made the protocol even more attractive. [ABSTRACT FROM AUTHOR]

Two new cytochalasans flavichalasine N ( 1 ), flavichalasine O ( 2 ), together with six known cytochalasans ( 3 – 8 ), were isolated from Aspergillus flavipes PJ03-11 through the application of OSMAC (one strain many compounds) strategy. Flavichalasine O ( 2 ) represented the first example of cytochalasans possessing a nitrogen-oxygen heterocycle at the macrocyclic ring part. Their structures were established on the base of extensive spectroscopic analysis. Compounds 1 – 4 exhibited significant cytotoxic activities against three human cancer cell lines (THP1, HL-60 and PC3) with IC 50 values ranging from 3.00 to 15.10 μM. [ABSTRACT FROM AUTHOR]

A simple method is reported for the synthesis of alkylaminophenols in moderate to good yields via a three-component, catalyst-free decarboxylative coupling of proline with salicylaldehyde and boronic acids. [ABSTRACT FROM AUTHOR]

Phosphonylation of the pretreated 2-(hydroxymethyl)phenol derivatives with acetic anhydride using trialkylphosphites as the nucleophilic reagents was reported, providing a practical way to the synthesis of novel highly steric 3,3′-bis-substituted benzo[ d ][1,2]oxaphosphole 2-oxides. [ABSTRACT FROM AUTHOR]

An environmental friendly process to selectively acetylate primary alcohols was demonstrated. The esterification process consists of treatment of a primary alcohol in the presence of immobilized C. antarctica lipase (Novozyme-435) in ethyl acetate at room temperature. Primary alcohols were acetylated in the presence of secondary alcohols and phenols. [ABSTRACT FROM AUTHOR]

TBAI/TBHP mediated oxidative cross coupling of phenols and carboxylic acids with ketones has been reported under metal-free, base free, solvent free conditions enabling environmentally benign synthesis of aryloxyketones, acyloxy ketones and benzofurans. Phenoxyketones and acyloxylcarbonyl compounds were synthesized in good to high yields, where as benzofurans were synthesized in moderate yields. This method is operationally simple, works under mild conditions, using commercially available as well as inexpensive TBAI and an oxidant TBHP. [ABSTRACT FROM AUTHOR]

The use of readily available ethyl acetate in the presence of iodine as an alternative acetylating agent is reported. Amines and phenols were unreactive under the examined reaction conditions, indicating that the method is highly chemoselective. [ABSTRACT FROM AUTHOR]

[Display omitted] Copper/oxalamide-catalyzed hydroxylation of aryl bromides has been boosted with respect to air-tolerance and compatibility with cost-effective hydroxides by using co-catalytic dialkylborinates, making the important protocol for phenols more practical without loss of catalytic efficiency. Scope and limitations of the copper/boron co-catalyzed hydroxylation of aryl bromides with potassium hydroxide in air have been demonstrated by more than 20 examples, showing good tolerance to steric and electronic factors albeit low compatibility with base-sensitive functional groups. The boosting effects of co-catalytic dialkylborinates are tentatively attributed to prevention of the catalytically active copper species from deactivation by air and free hydroxide. [ABSTRACT FROM AUTHOR]

[Display omitted] • Direct synthesis of new functionalized 2-oxopyrrole derivatives. • The first example of a combination of a phenolic moiety and dicyanoacrylamide (DCAA) fragment in the structure. • High-contrast reversible transformations with changing of the molar absorptivity in more than 4 times. A direct synthesis of previously unknown 2-[5-(4-hydroxyphenyl)-2-oxo-4-phenyl-1,2-dihydro-3 H -pyrrol-3-ylidene]malononitriles was carried out, which are donor–acceptor chromophores bearing phenol moiety as an electron-donor fragment. A developed synthetic route was based on the initial reaction of methoxy-substituted aryl ketones with tetracyanoethylene and resulted in 4-(4-methoxyphenyl)-4-oxo-3-butane-1,1,2,2-tetracarbonitriles, which were further converted into corresponding 2-[5-(4-methoxyphenyl)-2-oxo-1,2-dihydro-3 H -pyrrol-3-ylidene]malononitriles by the action of morpholine. Treatment of the latter with boron tribromide led to demethylation of the methoxy group and formation of the desired phenolic chromophores. The obtained phenol derivatives are intensely colored compounds found to be capable to reversible high-contrast phenol-phenolate (quinoid) transformation. Their solvatochromic behavior was directly related to the donor number (DN) of the solvent and well fitted to the Kamlet-Taft model. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ph 3 P·I 2 was used to mediate the deprotection of aryl alkyl ethers. • The method possesses comparatively broad substrate scope. • Metal-free and neutral reaction conditions were used. • A variety of aryl alkyl ethers can be highly efficiently deprotected. A highly efficient method for the deprotection of aryl alkyl ethers under metal-free and neutral conditions was developed by iodotriphenylphosphonium iodide [Ph 3 P+I]I− formed in situ through the reaction of equimolar PPh 3 and I 2. A variety of aryl alkyl ethers including aryl methyl/allyl/benzyl/ethyl/ n -propyl/ i -propyl/ n -butyl ethers can all be highly efficiently deprotected to release the corresponding phenols in good to excellent yields. [ABSTRACT FROM AUTHOR]

[Display omitted] 2-Arylphenols have been synthesized by KOH/DMSO mediated tandem S N Ar/desulfurization reactions of dibenzothiophene dioxide. Diversely substituted phenols such as 2,4-diarylated and challenging 2,5-diarylated ones are obtained in this transformation. Based on the experimental evidence, a mechanism is proposed. Synthetic utility of sulfinic ester and 2-arylphenol have been showcased. [ABSTRACT FROM AUTHOR]

Copper-catalyzed modified Ullmann coupling reactions creating C–O bonds, including diaryl ethers or phenols, are vital to organic synthesis. Synthesized N- phenyl-2-pyridinecarboxamide and its derivatives were used as ligands in conjunction with catalytic copper sources in the formation of various diaryl ethers and phenols. Various aryl and heteroaryl halides with electron donating and withdrawing groups were reacted with various phenols under mild reaction conditions providing moderate to excellent yields. [ABSTRACT FROM AUTHOR]

A new protocol to obtain 3-substituted 2-cyclohexenones, was developed by reversing the chemical reactivity of 2-cyclohexenone. One-pot synthesis of 3-substituted 2-cyclohexenones can be achieved by treatment of 3-phenylthiosilyl enol ether with a mixture of t -BuLi/HMPA that allows hydrogen-selective exchange in presence of reactive electrophiles such as aldehydes, ketones and alkyl halides. This affords the corresponding product in moderate overall yield, after silyl enol ether cleavage and concomitant thiophenol elimination initiated with TBAF. [ABSTRACT FROM AUTHOR]

This work reports simple, highly efficient protocol for the oxidation of arylboronic acids. Various arylboronic acids were selectively and completely converted into their corresponding oxidized phenols using H 2 O 2 as an oxidant in presence of catalytic amount of silica chloride. The results show that silica chloride is a suitable and efficient promoter for the oxidation of arylboronic acids. Heterogeneous catalyst, mild reaction conditions, easy availability of the reagent, easy work-up, excellent yield of corresponding phenols, short reaction time and broad substrate scope makes this protocol attractive and a practical alternative to the existing methods. [ABSTRACT FROM AUTHOR]

We accomplished the synthesis of 2-substituted benzofuran derivatives by the palladium-catalyzed reaction of 3-substituted propargylic carbonates with phenols. The 2-substituted benzofuran derivatives were obtained through the intermolecular coupling of the 3-substituted propargylic carbonates with phenols, and sequential intramolecular cyclization reaction. [ABSTRACT FROM AUTHOR]

A novel and efficient N,N ′-carbonyl diimidazole-catalyzed protocol for the direct esterification of P(O)-OH compounds using phenols as efficient esterification reagents is illustrated. It is a simple way to synthesis a broad spectrum of functionalized O -aryl phosphinates, phosphonates, and phosphates from basic starting materials with moderate to excellent yields. [ABSTRACT FROM AUTHOR]

A practical one-pot process for hydrodeoxygenation (HDO) of phenolic derivatives to their corresponding arenes was developed. This method provided a facile route to upgrading bio-oil. The substrate scope of this protocol was wide, complicated and multi-phenolic compounds were also smoothly hydrodeoxygenated to their corresponding arenes. [ABSTRACT FROM AUTHOR]

Selective dehydrogenation of 2-amino-3-cyano 4 H -chromenes to the corresponding 2-iminochromenes mediated by diisopropyl azodicarboxylate under neutral conditions is reported. The dehydrogenation reaction is compatible with phenolic hydroxyl group and generates iminochromene in high yields. The methodology provides an easy access to coumarin and N -tosyl 2-amino-3-cyano-4-aryl 4 H -chromenes. [ABSTRACT FROM AUTHOR]

An efficient methodology for the synthesis of aryl 1,2- cis -furanosidic linkages has been developed with 2-quinolinecarbonyl (Quin) group substituted furanose ethyl thioglycosides as glycosyl donors. The method permits a wide range of phenol acceptors to be used, thus resulting in the formation of structurally diverse phenol furanosides in good to excellent chemical yields with complete 1,2- cis anomeric selectivity. The synthetic utility of the approach has been demonstrated by concise preparation of the carbohydrate portion of antibiotic hygromycin A. [ABSTRACT FROM AUTHOR]

A simple and efficient method for the deoxygenation of amine N -oxides to corresponding amines is reported using the green and economical reagent phenylboronic acid. Deoxygenation of N , N -dialkylaniline N -oxides, trialkylamine N -oxides and pyridine N -oxides were achieved in good to excellent yields. The reduction susceptible functional groups such as ketone, amide, ester and nitro groups are well tolerated with phenylboronic acid during the deoxygenation process even at high temperature. In addition, an indirect method for identification and quantification of tert -amine N -oxide is demonstrated using UV–Vis spectrometry which may be useful for drug metabolism studies. [ABSTRACT FROM AUTHOR]

An expedient direct and regioselective thiocyanation of phenols, anilines and heterocycles is described. Transformation is realized via the direct C H functionalization under transition metal free conditions at ambient temperature in excellent yields. Method proved to be monoselective and variety of functional groups tolerated the reaction conditions. The practicality of the protocol is demonstrated in gram scale synthesis of a precursor of PPAR δ agonist in excellent yield. [ABSTRACT FROM AUTHOR]

We investigated the intermolecular coupling reaction of 2-fluoroallylic acetates with simple phenols by the [Pd(C 3 H 5 )Cl] 2 , DPPF, and KHMDS at 100 °C for 16 h, and succeeded in obtaining 2-substituted benzofuran derivatives in good to high yield through the C–F bond activation and intermolecular cyclization. [ABSTRACT FROM AUTHOR]

Copper boryl reagents enable the selective cleavage of aryl allyl ethers to the corresponding phenols in good to moderate yields. [ABSTRACT FROM AUTHOR]

[Display omitted] Sodium percarbonate (2Na 2 CO 3 ·3H 2 O 2 , sodium carbonate-hydrogen peroxide, SPC), an easily accessible and bench-stable hydrogen peroxide-solid adduct based on inorganic salt, was efficiently used as a solid hydroxylating reagent for the ipso -hydroxylation of arylboronic acids under mild conditions, affording the corresponding phenols in an excellent manner at a fast rate. Moreover, a solvent-free solid-state reaction system using SPC for the oxidative hydroxylation of arylboronic acids was also demonstrated. Furthermore, subsequent treatment with benzyl halide was successfully performed, providing an alternative synthetic route for preparing benzyl phenyl ethers in a one-pot tandem reaction system. [ABSTRACT FROM AUTHOR]

[Display omitted] Allyl phenyl ethers are efficiently formed by generating 2-allyloxy-1-methylpyridinium triflate in situ followed by reaction with a phenol substrate under mildly basic conditions. Electron-poor phenols give excellent yields of the corresponding allyl phenyl ether, while electron-rich phenols typically give more complicated crude reactions mixtures, and ultimately lower yields of isolated ether product. Interestingly, one of the critical factors for a successful reaction is the shape and size of the reaction vessel, potentially due to maximizing the surface area of the insoluble molten oxypyridinium salt and the rest of the reaction mixture. The addition of dibenzo-18-crown-6 helps the efficiency of the reaction, presumably by slightly improving the solubility of the reaction components. These reaction conditions indicate that both the nucleophilic and electrophilic components of these reactions are important for an efficient reaction, even though the mechanism of substitution has typically been described as "S N 1-like." [ABSTRACT FROM AUTHOR]

The 4,4′-(9,9-dimethylfluorene-2,7-diyl)dibenzoic acid ( 5 ) was synthesized using commercial fluorene as the starting material followed by processes of bromination, methylation, Suzuki coupling and hydrolysis. We reported it as an exclusive fluorescence sensor for 2,4,6-trinitrophenol (TNP) and acetate ions for the first time. The experimental results suggested a high efficiency for TNP detection with K SV values of 21,215 M −1 , which has achieved to micromolar level (10 μM) of this material. Moreover, the detection limit (1.39 × 10 −6 M) was measured according to the fluorescence intensity changes of Ac − in CH 3 CN. [ABSTRACT FROM AUTHOR]

A novel and efficient TMSCl-mediated cyclization reaction of easily prepared 2-propynolphenols/anilines is developed to give 4-chloro-2 H -chromenes and 1,2-dihydroquinolines in good to efficient yields. It is noted that TMSCl acts not only as a promoter in this reaction, and also as the chloro source. Both tertiary and secondary propargylic alcohols with diverse functional groups were tolerated under mild conditions. Moreover, this method can be enlarged to gram scale (yield up to 90%). [ABSTRACT FROM AUTHOR]

[Display omitted] A visible-light-induced strategy for the synthesis of phenolic compounds was developed through palladium-catalyzed C H hydroxylation of aromatics with nitrogen-heterocyclic as the directing group and hydrogen peroxide as hydroxylation reagent. Diverse (hetero)arenes with nitrogen-heterocyclic directing groups can be utilized for the ortho C H hydroxylation under mild reaction conditions, and a series of phenolic compounds were synthesized in good yields. The protocol has good functional group tolerance and wide substrate scope, have been successfully applied to the synthesis of natural product caboxamycin and drug deferasirox. According to the experimental results and literature survey, a radical mechanism for the light-induced C H hydroxylation was proposed. This protocol provides a new solution for the preparation of phenolic compounds by C H bond activation hydroxylation. [ABSTRACT FROM AUTHOR]

[Display omitted] Intermolecular enantioselective oxidative para -dearomatization of phenols with the addition of methanol, catalyzed by a chiral 2-iodoresorcinol/lactamide, has been developed. The reaction allows for the synthesis of a broad range of 4-methoxy-2,5-cyclohexadienone products with up to 62% ee (from 2,4-disubstituted phenols in 43–62% ee; from a 3,4-disubstituted phenol in 17% ee; from 4-substituted-1-napthols in 38–44% ee). Reported results constitute a proof of concept that the enantioselectivity in challenging intermolecular dearomatization of phenols can be considerably improved in a simple way, namely, by increasing the steric bulk of the coupling partner upon replacing water with methanol. [ABSTRACT FROM AUTHOR]

Oxidative dearomatization of 2- and 4-substituted phenols to their corresponding benzoquinone monoketals by catalytic amount of iodobenzene, and m -CPBA as a co-oxidant has been achieved via in situ generation of PhIO 2 , a hypervalent iodine(V) species. The transiently generated orthobenzoquinone monoketals further underwent Diels–Alder reaction with various dienophiles to furnish densely substituted bicyclo[2.2.2]octenones in high selectivities and yields. This methodology features ready availability of reagents, cost effectiveness, safety, brevity, selectivity, diversity and excellent yields. [ABSTRACT FROM AUTHOR]

A novel synthesis of coumarin derivatives by Brønsted acid-mediated condensation and intramolecular cyclization of phenols and propiolic acids was reported. This transformation requires the use of TfOH in place of a conventional metal mediator, and it occurs under mild conditions and provides rapid access to coumarin derivatives in good yields. [ABSTRACT FROM AUTHOR]

Coumarins are a well-known class of natural occurring and semi-synthetic products with reported important and effective pharmacological activities. In this Letter an improved method for the chemical synthesis of such compounds is described. Coumarins have been obtained in good to excellent yields under microwave irradiation and solvent-free conditions in a short time from differently substituted phenols and propiolic acids used as starting materials in the presence of Yb(OTf) 3 hydrate 10% mol as the catalyst. [ABSTRACT FROM AUTHOR]

The synthesis of oligo(ethylene glycol) with biphenolic gallates as termini and their assembly to dimeric structures upon spiroborate formation are described. Complexation of these dimeric structures with alkali metal ions showed selectivity to lithium and potassium by tuning the length of the ethyleneoxy units. The methoxycarbonyl group on the dimeric compound could be manipulated in harsh conditions without destruction of the dimeric structure. [ABSTRACT FROM AUTHOR]

An efficient and practical method for the chemoselective ipso -hydroxylation of arylboronic acids is demonstrated using urea-hydrogen peroxide under catalyst free condition at room temperature. Remarkably, oxidation sensitive functional groups such as olefin, aldehyde, alcohol, ketone, and sulfide as well as heterocycles such as pyridine and thiophene were tolerated under the standard reaction condition. In addition to the solution phase, a solid phase ipso -hydroxylation of arylboronic acids has been investigated with urea hydrogen peroxide. The scope and limitations of the solid phase protocol is discussed. [ABSTRACT FROM AUTHOR]

Bicyclic dioxetane 1 bearing a 3-hydroxyphenyl group underwent thermal decomposition in solution (TD soln ) to form 3-oxopentyl 3-hydroxybenzoate 4 accompanied by the emission of light [ λ max CL (TD soln ) = 405 nm] due to an excited 3-oxopentyl group in 4 . Dioxetane 1 also exclusively gave 4 by thermal decomposition in crystal (TD cryst ). However, in contrast to TD soln , TD cryst of 1 gave light [ λ max CL (TD cryst ) = 464 nm] due to excited oxidobenzoate 3 ∗ and/or its closely related species formed by CTID (charge-transfer induced decomposition) mechanism. The unique chemiluminescent TD cryst of 1 was presumably the result of hydrogen bonding formed in the crystal between the phenolic proton of a dioxetane molecule and a peroxide oxygen of another dioxetane molecule. In this work, TD cryst as well as TD soln of bicyclic dioxetane analog bearing a 4-fluorenyl-3-hydroxyphenyl moiety 10 and of adamantylidene-dioxetane bearing a 3-hydroxyphenyl group 5b were also investigated. [ABSTRACT FROM AUTHOR]

A series of tert -butanesulfinamide type compounds, which were decorated with phenol receptors, were found to recognize chlorine ion, nitrate ion, and acetate ion by 1 H NMR titration experiments. The results indicated that the interaction between subject molecule and anion was enhanced with the increase of the acidity of the phenolic O–H group. Furthermore, the tert -butyl group seemed to play a role in the anion recognition. [ABSTRACT FROM AUTHOR]

We report the spectroscopic characterization, DNA binding, and anion sensor properties, of a Schiff base, that is, ( E )-2-[(6-methoxybenzo[ d ]thiazol-2-ylimino)methyl]phenol from the reaction of 2-hydroxybenzaldehyde with 2-amino-6-methoxybenzothiazole. Colorimetric measurements revealed that the title compound was sensitive to F − , AcO − , CN − , and OH − anions. Fluorescence measurements demonstrated that the title compound can be used to detect CN − . The interactions between the receptor and anions were confirmed using 1 H NMR titration method. The UV–Vis spectroscopy studies of the interactions between the compound and calf thymus DNA (CT-DNA) revealed intercalative binding of CT-DNA to the title compound. [ABSTRACT FROM AUTHOR]

A new kind of chiral compounds with multiple amino, amido and phenolic hydroxy groups has been synthesized from d -phenylalanine and d -phenylglycine, respectively. The enantiomeric discriminations of α-hydroxy acids and N -Ts-α-amino acids have been finished in the presence of the above chiral compounds as chiral solvating agents by 1 H NMR spectroscopy. The results show that the chiral compounds are highly effective and practical chiral solvating agents towards α-hydroxy acids and N -Ts-α-amino acids. [ABSTRACT FROM AUTHOR]

[Display omitted] Despite significant progress in the area of enaminone vinyl C H functionalization, approaches for the direct synthesis of phenoxyl enaminone molecules remain a challenge. Here we describe a highly efficient 1,3‑Dibromo 5,5-dimethylhydantoin (DBDMH)-promoted cross-coupling reaction between enaminones and phenols. This method provides straightforward access to a wide range of polyfunctionalized aminophenoxyalkenes under mild conditions. The main advantageous features of this method includes a wide substrate scope and good functional group tolerance, operational simplicity, and easily available starting materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • benzylic C H heteroarylation of 4-methylphenols with 2 H -indazoles. • K 2 S 2 O 8 -promoted C(sp3)−H and C(sp2)−H bonds cross-dehydrogenative coupling reaction. • Metal-free radical reaction. A simple benzylic C H heteroarylation of 4-methylphenols was developed via the K 2 S 2 O 8 -promoted C(sp3)−H and C(sp2)−H bonds cross-dehydrogenative coupling with 2 H -indazoles under transition-metal free conditions. A variety of 4-((2 H -indazol-3-yl)methyl)phenols were obtained in moderate to good yields. Mechanistic investigation indicated that the reactions probably proceed through a radical pathway. [ABSTRACT FROM AUTHOR]