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Design and synthesis of 3,4-methylenedioxy-6-nitrophenoxyacetylhydrazone derivatives obtained from natural safrole: New lead-agents with analgesic and antipyretic properties
In this work, we reported the synthesis and evaluation of the analgesic, anti-inflammatory, and antipyretic properties of new 2-(6-nitro-benzo[1,3]dioxol-5-yloxy)-acetylhydrazone derivatives (3), designed exploring molecular hybridization and isosteric replacement approaches between nimesulide (1) and carbanalogue NAH series (2) developed at LASSBio. Target compounds were synthesized in very good yields exploiting abundant Brazilian natural product safrole (4) as starting material. The evaluation of the antinociceptive properties of this series led us to discover a new potent prototype of analgesic and antipyretic agent, that is, NAH derivative 3c, named LASSBio-891, which showed to be more potent than dipyrone used as standard.
Bezerra-Netto, Heleno J.C.,Lacerda, Daniel I.,Miranda, Ana Luisa P.,Alves, Helio M.,Barreiro, Eliezer J.,Fraga, Carlos A.M.
p. 7924 - 7935
(2006)
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Formation of Samin Diastereomers by Acid-Catalyzed Transformation of Sesamolin with Hydrogen Peroxide
The conversion of sesame lignans is of interest because the derived products may have potential applications. Here, in investigating the transformation of sesamin and sesamolin, main endogenous sesame lignans in sesame seeds, in both acidic aqueous and anhydrous systems, 7R,7′S-samin was identified as one of the major products of sesamolin in both systems catalyzed with common inorganic acids, but sesaminol was not generated. In investigating the effect of different oxidizing agents on the acid-catalyzed conversion of sesame lignans, 7R,7′S-samin was still the major product of sesamolin, whereas sesamolin as well as 7R,7′S-samin stereoselectively rendered 7R,7′R-samin in the presence of hydrogen peroxide. Hydrogen peroxide may play a role in stabilizing the transitional oxonium ions, derived from acid hydrolysis of sesamolin or 7R,7′S-samin by forming a seven-membered ring intermediate through hydrogen bonding, to consequently produce 7R,7′R-samin as the final product.
Chu, I-Hsuan,Hung, Wei-Ching,Lee, Wei-Ju,Su, Nan-Wei,Tsai, Hsin-Ya
p. 6430 - 6438
(2020)
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Preparation method of sesamol
The invention belongs to the technical field of compound synthesis, and particularly relates to a preparation method of sesamol, which firstly prepares 2 -chloro -1, 4 -diphenol, and then 2 - chlorine -1, 4 -biphenol and sodium hydroxide in an aqueous solution to obtain the sesamol, namely 1 2, 1 2 4 - 4 -triphenol and dichloromethane. The invention provides a new method for preparing the sesame phenol, and the yield of the sesamol is remarkably improved.
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Paragraph 0022; 0026; 0032-0035

(2021/11/21)

AN EFFICIENT PROCESS FOR PREPARATION OF ACYL DERIVATIVES OF ALKYLENEDIOXYBENZENES
The present disclosure provides a process of preparation of compounds of Formula I comprising the step of : reacting an alkylenedioxybenzene compound of Formula II with an acyl halide of Formula III in presence of a solvent, wherein the step of reacting the alkylenedioxybenzene compound of Formula II with the acyl halide of Formula III is effected in presence of an amphoteric oxide and a Lewis acid so as to immediately quench the compound of formula H-X, formed during the course of the reaction, to substantially eliminate degradation of the compound of any of Formula I and II. The present disclosure also provides for process(es) for preparation of compound of Formula IVa, IVb and IVc.
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Paragraph 0099

(2021/08/20)

Synthesis process 3,4 -methylenedioxy phenol
The invention relates to the technical field of compound synthesis, in particular to a synthesis process of 3,4 -methylenedioxy phenol, which comprises the following steps: 3,4 - methylenedioxy acetophenone. The second Catalyst, first solvent was added to the autoclave, and an oxidant was added, and reacted 25 - 50 °C under 4 - 8h, and the first solvent was separated and the solvent was separated. The resulting 3,4 -methylenedioxy phenol acetate is obtained. The second Solvent, sodium hydroxide solution was added to the autoclave, and reacted 20 - 60 °C at 2 - 6h, adjusted pH to 3-6 to obtain 3,4 - methylenedioxy phenol. The method solves the problems that 3,4 -methylenedioxy acetophenone in the prior art is low in yield and large in separation difficulty in preparation of sesame phenol. The process takes the pepper ring as the starting raw material and is divided into three-step reaction synthesis, the raw material conversion rate is high, no other side reaction is avoided, the reaction condition is mild, the production cost is low, and the product quality is better.
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Paragraph 0027; 0031; 0033; 0037; 0038; 0042; 0043; ...

(2021/10/30)

Nickel-catalyzed deallylation of aryl allyl ethers with hydrosilanes
An efficient and mild catalytic deallylation method of aryl allyl ethers is developed, with commercially available Ni(COD)2 as catalyst precursor, simple substituted bipyridine as ligand and air-stable hydrosilanes. The process is compatible with a variety of functional groups and the desired phenol products can be obtained with excellent yields and selectivity. Besides, by detection or isolation of key intermediates, mechanism studies confirm that the deallylation undergoes η3-allylnickel intermediate pathway.
Ding, Guangni,Fan, Sijie,Wang, Jingyang,Wang, Yu,Wu, Xiaoyu,Xie, Xiaomin,Yang, Liqun,Zhang, Zhaoguo
supporting information

(2021/09/28)

Preparation method of 3,4-methylenedioxy phenol
The invention discloses a preparation method of 3,4-methylenedioxy phenol. The preparation method is characterized in that 3,4-(methylenedioxy)acetophenone is used as an initial raw material, hydrogenperoxide is dropwise added into a toluene-formic acid solution for an oxidation reaction, and the obtained substance is hydrolyzed, neutralized and rectified to obtain the target product 3,4-(methylenedioxy)acetophenone. The method has the advantages of easy availability of raw materials, mild and safe reaction conditions, high product purity and high yield, and is simple and convenient to operate.
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Paragraph 0022-0034

(2020/07/02)

Method for preparing alcohol and phenol through aerobic hydroxylation reaction of boric acid derivative in absence of photocatalyst
The invention discloses a method for preparing alcohol and phenol through aerobic hydroxylation reaction of a boric acid derivative in the absence of a photocatalyst, wherein the boric acid derivativeis aryl boronic acid or alkyl boronic acid, and the corresponding target compounds are respectively a phenol-based compound and an alcohol-based compound. According to the method, by using a boric acid derivative as a reaction substrate, an additive is added under a solvent condition, and a hydroxylation reaction is performed under aerobic and illumination conditions to obtain a corresponding target compound. According to the invention, the new strategy is provided for the synthesis of phenols through aerobic hydroxylation of aryl boronic acid without a photocatalyst; the catalyst-free aerobic hydroxylation method for photocatalysis of aryl boronic acid or alkyl boronic acid by using triethylamine as an additive is firstly disclosed; and the new method has advantages of photocatalyst-freecondition, wide substrate range and good functional group compatibility.
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Paragraph 0025-0028; 0030-0032

(2020/01/25)

Development of a Cross-Conjugated Vinylogous [4+2] Anionic Annulation and Application to the Total Synthesis of Natural Antibiotic (±)-ABX
The cross-conjugated vinylogous [4+2] anionic annulation has been newly developed, the cascade process of which has a high preference for regiochemical control and chemoselectivity, giving rise to exclusively Michael-type adducts in moderate to high yields (up to 94 %, 35 examples). By making use of this approach as a key operation, the first total synthesis of natural antibiotic ABX, in racemic form, has been successfully achieved in a concise 7-step sequence with an overall yield of about 20 %.
Huang, Jing-Kai,Shia, Kak-Shan
supporting information
p. 6540 - 6545
(2020/03/03)

Rongalite-promoted metal-free aerobic ipso-hydroxylation of arylboronic acids under sunlight: DFT mechanistic studies
A novel rongalite-promoted metal-free aerobic ipso-hydroxylation of arylboronic acids has been developed. This method employs low-cost rongalite as a radical initiator and O2 as a green oxidizing agent for ipso-hydroxylation. This protocol is compatible with a wide variety of functional groups with good to excellent yields at room temperature. Furthermore, mechanistic insight into the role of superoxide radical anions in C-B cleavage has also been provided based on DFT studies.
Golla, Sivaparwathi,Poshala, Soumya,Pawar, Ravinder,Kokatla, Hari Prasad
supporting information

(2019/12/27)

Bimetallic photoredox catalysis: Visible light-promoted aerobic hydroxylation of arylboronic acids with a dirhodium(ii) catalyst
We report the use of a rhodium(II) dimer in visible light photoredox catalysis for the aerobic oxidation of arylboronic acids to phenols under mild conditions. Spectroscopic and computational studies indicate that the catalyst Rh2(bpy)2(OAc)4 (1) undergoes metal-metal to ligand charge transfer upon visible light irradiation, which is responsible for catalytic activity. Further reactivity studies demonstrate that 1 is a general photoredox catalyst for diverse oxidation reactions.
Campbell, Michael G.,Chuang, Gary Jing,Liu, Ming-Lun,Miura-Stempel, Emily,Tu, Jing-Wen,Yang, Hsiang-Ming
p. 2040 - 2047
(2020/03/13)

Palladium-Catalyzed Visible-Light-Driven Carboxylation of Aryl and Alkenyl Triflates by Using Photoredox Catalysts
A visible-light-driven carboxylation of aryl and alkenyl triflates with CO2 is developed by using a combination of Pd and photoredox catalysts. This reaction proceeds under mild conditions and can be applied to a wide range of substrates including acyclic alkenyl triflates.
Shimomaki, Katsuya,Nakajima, Tomoya,Caner, Joaquim,Toriumi, Naoyuki,Iwasawa, Nobuharu
supporting information
p. 4486 - 4489
(2019/06/24)

Phthalocyanine Zinc-catalyzed Hydroxylation of Aryl Boronic Acids under Visible Light
A visible-light-promoted aerobic oxidative hydroxylation of boronic acids using phthalocyanine zinc as an easily available photosensitizer has been developed. It provided a direct access to synthesize aliphatic alcohols and phenols from boronic acids. The advantages of this approach included the low catalyst loading (0.5 mol%), high efficient, the use of O2 as an oxygen source, wide substrate range, the simple operational process, and mild conditions. (Figure presented.).
Luo, Dong-Ping,Huang, Yang-Feng,Hong, Xiao-Yi,Chen, Dingben,Li, Guo-Xing,Huang, Xiao-Bo,Gao, Wen-Xia,Liu, Miao-Chang,Zhou, Yun-Bing,Wu, Hua-Yue
supporting information
p. 961 - 964
(2019/01/25)

Cellulose as recyclable organocatalyst for ipso-hydroxylation of arylboronic acids
Cellulose catalyzed oxidative hydroxylation of aryl and hetero-arylboronic acids to the corresponding phenols under metal and base free strategy has been demonstrated. The sustainable ipso-hydroxylation takes place using hydrogen peroxide as an oxidant in water under mild condition in shorter period of time. Interestingly, easy recovery and reusability of heterogeneous catalyst without significant loss in catalytic yield makes the protocol environmentally benign.
Laskar, Khairujjaman,Paul, Subham,Bora, Utpal
(2019/08/26)

Photoinduced hydroxylation of arylboronic acids with molecular oxygen under photocatalyst-free conditions
Photoinduced hydroxylation of boronic acids with molecular oxygen under photocatalyst-free conditions is reported, providing a green entry to a variety of phenols and aliphatic alcohols in a highly concise fashion. This new protocol features photocatalyst-free conditions, wide substrate scope and excellent functional group compatibility.
Xu, Yu-Ting,Li, Chen-Yuan,Huang, Xiao-Bo,Gao, Wen-Xia,Zhou, Yun-Bing,Liu, Miao-Chang,Wu, Hua-Yue
supporting information
p. 4971 - 4975
(2019/09/30)

Application of quebrachitol in hydrolysis reaction of copper-catalyzed aryl halide
The invention belongs to the technical field of drug synthesis, and provides application of quebrachitol in a hydrolysis reaction of a copper-catalyzed aryl halide. According to the hydrolysis reaction, copper serves as a catalyst, quebrachitol serves as a ligand, and the hydrolysis reaction is carried out on the aryl halide. The invention further provides a catalytic system of the hydrolysis reaction of the aryl halide. The reaction system comprises the copper catalyst, the quebrachitol, alkali and water, and the system is environmentally friendly and is suitable for industrial application.
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Paragraph 0087-0089

(2019/07/16)

Novel synthesis method of sesamol
The invention discloses a novel synthesis method of sesamol. The method specifically comprises the following steps: first, gamma-glycidyl oxypropyl trimethoxysilane is used as a dispersing agent to prepare modified mullite powder; then, the modified mullite powder is used as a carrier to prepare a supported catalyst; catechol and dichloromethane are used as raw materials to prepare 1,3-benzodioxole under the catalysis of the supported catalyst; glyoxylic acid, a sulfuric acid solution and 1,3-benzodioxole are used as raw materials to obtain 3,4-methylenedioxy phenyl glycolic acid; the 3,4-methylenedioxy phenyl glycolic acid reacts with a nitric acid solution to prepare piperonal; finally, the piperonal and MCPBA react to prepare the sesamol. The method disclosed in the invention is simpleto operate, low in preparation cost and high in product yield.
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Paragraph 0026; 0032; 0039; 0046; 0053

(2018/11/22)

Development of a novel protocol for chemoselective deprotection of N/O-benzyloxycarbonyl (Cbz) at ambient temperature
Abstract: A novel protocol for the deprotection of N-benzyloxycarbonyl and O-benzyloxycarbonyl groups by nickel boride generated in situ from NaBH4 and NiCl2·6H2O in methanol at room temperature has been developed to give the corresponding amines and phenols. This protocol is chemoselective as groups like chloro, bromo, amide, ester, pyridine, and tert-butyloxycarbonyl moiety are unaffected under these conditions. The deprotection has also been validated in gram scale reactions, to establish the wider appropriateness of this protocol. Graphical abstract: [Figure not available: see fulltext.].
Saroha, Mohit,Aggarwal, Komal,Bartwal, Gaurav,Khurana, Jitender M.
p. 2231 - 2235
(2018/10/02)

Efficient dealkylation of aryl alkyl ethers catalyzed by Cu2O
An efficient protocol for dealkylation of aryl alkyl ethers under the catalysis of inexpensive and easily reusable Cu2O has been described. The phenol products were obtained in high yields, and a range of functional groups were well tolerated. The choice of solvent is critical to the catalysis, and CH3OH proved to be the optimal choice. Mechanistic investigations showed that this reaction possibly proceeds via a single-electron transfer (SET) process.
Liu, Lingxian,Li, Zengguang,Chen, Changjun,Li, Huanrong,Xu, Lijin,Yu, Zhiyong
supporting information
p. 2447 - 2453
(2018/04/11)

AMINATION AND HYDROXYLATION OF ARYLMETAL COMPOUNDS
In one aspect, the present disclosure provides methods of preparing a primary or secondary amine and hydroxylated aromatic compounds. In some embodiments, the aromatic compound may be unsubstituted, substituted, or contain one or more heteroatoms within the rings of the aromatic compound. The methods described herein may be carried out without the need for transition metal catalysts or harsh reaction conditions.
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Paragraph 0098; 0226; 0241

(2018/03/25)

Synthesis of Phenols: Organophotoredox/Nickel Dual Catalytic Hydroxylation of Aryl Halides with Water
A highly effective hydroxylation reaction of aryl halides with water under synergistic organophotoredox and nickel catalysis is reported. The OH group of the resulting phenols originates from water, following deprotonation facilitated by an intramolecular base group on the ligand. Significantly, aryl bromides as well as less reactive aryl chlorides served as effective substrates to afford phenols with a wide range of functional groups. Without the need for a strong inorganic base or an expensive noble-metal catalyst, this process can be applied to the efficient preparation of diverse phenols and enables the hydroxylation of multifunctional pharmaceutically relevant aryl halides.
Yang, Liu,Huang, Zhiyan,Li, Gang,Zhang, Wei,Cao, Rui,Wang, Chao,Xiao, Jianliang,Xue, Dong
supporting information
p. 1968 - 1972
(2018/02/06)

Synergistic Photo-Copper-Catalyzed Hydroxylation of (Hetero)aryl Halides with Molecular Oxygen
Photoredox-mediated copper-catalyzed hydroxylation of (hetero)aryl halides (including chlorides, bromides, and iodides) with O2 at room temperature has been developed. Preliminary mechanistic studies indicate no arylcopper intermediate and that aryl radicals are involved in this procedure. 18O-labeling experiments confirm the hydroxyl oxygen atom originated from molecular oxygen.
Zhang, Xin,Wu, Ge,Gao, Wenxia,Ding, Jinchang,Huang, Xiaobo,Liu, Miaochang,Wu, Huayue
supporting information
p. 708 - 711
(2018/02/09)

METHOD FOR PRODUCING HIGH-PURITY PHENOLIC COMPOUND
PROBLEM TO BE SOLVED: To provide a method for producing a high-purity phenolic compound. SOLUTION: A method for producing high-purity phenol has a step 1 of producing aromatic aldehyde of formula (2) by the reaction between aromatic methyl alcohol of formula (1) and peroxide, a step 2 of producing phenol of formula (3) by the reaction between the formula (2) and peroxide in the presence of acid catalyst, and a step of purifying the formula (3). SELECTED DRAWING: None COPYRIGHT: (C)2017,JPO&INPIT
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Paragraph 0159-0161

(2017/07/23)

Rapid heteroatom transfer to arylmetals utilizing multifunctional reagent scaffolds
Arylmetals are highly valuable carbon nucleophiles that are readily and inexpensively prepared from aryl halides or arenes and widely used on both laboratory and industrial scales to react directly with a wide range of electrophiles. Although C-C bond formation has been a staple of organic synthesis, the direct transfer of primary amino (-NH2) and hydroxyl (-OH) groups to arylmetals in a scalable and environmentally friendly fashion remains a formidable synthetic challenge because of the absence of suitable heteroatom-transfer reagents. Here, we demonstrate the use of bench-stable N-H and N-alkyl oxaziridines derived from readily available terpenoid scaffolds as efficient multifunctional reagents for the direct primary amination and hydroxylation of structurally diverse aryl- and heteroarylmetals. This practical and scalable method provides one-step synthetic access to primary anilines and phenols at low temperature and avoids the use of transition-metal catalysts, ligands and additives, nitrogen-protecting groups, excess reagents and harsh workup conditions.
Gao, Hongyin,Zhou, Zhe,Kwon, Doo-Hyun,Coombs, James,Jones, Steven,Behnke, Nicole Erin,Ess, Daniel H.,Kürti, László
p. 681 - 688
(2017/06/30)

Asymmetric glycolate alkylation approach towards total synthesis of 8-O.6′ and 8-O.4′-neolignans
The glycolate alkylation approach for the total synthesis of 8-O.6′ and 8-O.4′-neolignans has been optimized affording the natural products with high overall yields and excellent stereoselectivity. The developed approach can be further utilized towards the synthesis of many natural and unnatural neolignans. This is the first approach for the synthesis of neolignans using asymmetric glycolate alkylation approach.
Gangar, Mukesh,Chouhan, Mangilal,Goyal, Sandeep,Harikrishnan,Chandran,Ittuveetil, Avinash,Nair, Vipin A.
supporting information
p. 5931 - 5934
(2016/12/09)

Copper-Catalyzed Hydroxylation of (Hetero)aryl Halides under Mild Conditions
The combination of Cu(acac)2 and N,N′-bis(4-hydroxyl-2,6-dimethylphenyl)oxalamide (BHMPO) provides a powerful catalytic system for hydroxylation of (hetero)aryl halides. A wide range of (hetero)aryl chlorides bearing either electron-donating or -withdrawing groups proceeded well at 130 °C, delivering the corresponding phenols and hydroxylated heteroarenes in good to excellent yields. When more reactive (hetero)aryl bromides and iodides were employed, the hydroxylation reactions completed at relatively low temperatures (80 and 60 °C, respectively) at low catalytic loadings (0.5 mol % Cu).
Xia, Shanghua,Gan, Lu,Wang, Kailiang,Li, Zheng,Ma, Dawei
supporting information
p. 13493 - 13496
(2016/10/31)

Formation of 2,2-dimethylchroman-4-ones during the photoinduced rearrangement of some aryl 3-methyl-2-butenoate esters. A mechanistic insight
Several aryl 3-methyl-2-butenoate esters upon irradiation lead to the formation of [1,3]-migrated photoproducts, phenol and, surprisingly 2,2-dimethylchroman-4-one derivatives. The starting photochemical reaction takes place from the singlet excited state of the ester and as a total mechanism two consecutive reaction pathways are proposed. The former involves the photo-Fries rearrangement of the esters in all the solvents studied and, depending on the proticity of the solvent, the latter involves an ESIPT process followed by thermal 6π-electrocyclic reaction and/or thermal (intramolecular oxa-Michael addition) cyclization of the ortho regioisomers photoformed. This second pathway is responsible of the formation of the 2,2-dimethylchroman-4-one derivatives.
Iguchi, Daniela,Erra-Balsells, Rosa,Bonesi, Sergio M.
p. 1903 - 1910
(2016/04/05)

Synthesis, characterization and application of poly(N,N'-dibromo- Nethylnaphthyl-2,7-disulfonamide) as an efficient catalyst for the acetylation and deacetylation reactions
In this work, a novel polymer namely poly(N,N'-dibromo-N-ethylnaphthyl-2,7- disulfonamide) (PBNS) is synthesized and characterized by studying its IR, 1H NMR, 13C NMR and thermal gravimetric analysis (TGA). This polymer is utilized as a highly efficient, heterogeneous and recyclable N-bromo reagent to catalyze acetylation of various compounds such as alcohols, phenols, thiol and amine with acetic anhydride under solvent-free conditions, and also it worthily catalyzes deacetylation of acetate esters in aqueous media.
Khazaei, Ardeshir,Saednia, Shahnaz,Roshani, Liela,Kazem-Rostami, Masoud,Zare, Abdolkarim
p. 159 - 167
(2014/05/20)

Continuous-flow synthesis of functionalized phenols by aerobic oxidation of grignard reagents
Phenols are important compounds in chemical industry. An economical and green approach to phenol preparation by the direct oxidation of aryl Grignard reagents using compressed air in continuous gas-liquid segmented flow systems is described. The process tolerates a broad range of functional groups, including oxidation-sensitive functionalities such as alkenes, amines, and thioethers. By integrating a benzyne-mediated in-line generation of arylmagnesium intermediates with the aerobic oxidation, a facile three-step, one-flow process, capable of preparing 2-functionalized phenols in a modular fashion, is established. Putting on airs: Aerobic oxidation of (hetero)aryl Grignard reagents using compressed air proceeds with a gas-liquid continuous-flow system, thus enabling preparation of fucntionalized phenols. By integrating an in-line generation of ArMgBr intermediates with the aerobic oxidation, ortho-functionalized phenols can be assembled. The method demonstrates good functional-group (FG) compatibility, mild reaction conditions, and short reaction times.
He, Zhi,Jamison, Timothy F.
supporting information
p. 3353 - 3357
(2014/04/03)

Ethylene glycol as hydrogen donor for the syntheses of thymol analogues via hydrolysis of 4-methylcoumarins
Treatment of 4-methylcoumarins with potassium hydroxide in ethylene glycol resulted in the formation of the 'normal' 2-isopropenylphenols and/or the 'abnormal' 2-isopropylphenols depending on the nature of the substrates. The solvent ethylene glycol was b
Chang, Junbiao,Wang, Shuyang,Shen, Zhenhua,Huang, Gang,Zhang, Yueteng,Zhao, Jing,Li, Changwei,Fan, Fangfang,Song, Chuanjun
supporting information
p. 6755 - 6757,3
(2012/12/12)

Efficient microwave-assisted Pd-catalyzed hydroxylation of aryl chlorides in the presence of carbonate
An efficient microwave-assisted, palladium-catalyzed hydroxylation of aryl chlorides in the presence of a weak base carbonate was developed, which rapidly converts aryl and heteroaryl chlorides to phenols, and can be used when the aryl chloride is functionalized with a ketone, aldehyde, ester, nitrile, or amide.
Yu, Chao-Wu,Chen, Grace S.,Huang, Chen-Wei,Chern, Ji-Wang
supporting information; experimental part
p. 3688 - 3691
(2012/08/28)

Design and synthesis of C-ring lactone- and lactam-based podophyllotoxin analogues as anticancer agents
A series of novel podophyllotoxin (PDT) analogues was synthesized in which the lactone moiety was shifted to C ring. Some of the derivatives were also synthesized with modified A ring. Analogues 23 and 25 exhibited potent in vitro cytotoxicity against colon cancer (CaCO2) cell line. p-Demethylated E-ring analogues exhibited better potency than the corresponding methylated analogues. These analogues showed toxicity comparable to PDT against human erythrocytes albeit at much higher concentrations (100 μg/ml) than their cytotoxicity values.
Singh, Pragya,Faridi, Uzma,Srivastava, Suchita,Kumar, Jonnala Kotesh,Darokar, Mahender Pandurang,Luqman, Suaib,Shanker, Karuna,Chanotiya, Chandan Singh,Gupta, Atul,Gupta, Madan Mohan,Negi, Arvind Singh
scheme or table
p. 242 - 246
(2010/08/04)

Eco-friendly hydrodehalogenation of electron-rich aryl chlorides and fluorides by photochemical reaction
Aryl chlorides and fluorides are smoothly hydrodehalogenated by irradiation either in neat i-PrOH or in a polar solution in the presence of hypophosphorous acid or triethylsilane. The procedure gives the halogen-free products in good to excellent yields under mild eco-friendly conditions and avoids the recourse to toxic metal catalysts.
Dichiarante, Valentina,Fagnoni, Maurizio,Albini, Angelo
experimental part
p. 942 - 945
(2010/04/23)

Sesamol Derivatives or Their Salts, The Process for Preparing the Same, and the Skin External Composition Containing the Same
The present invention relates to a sesamol derivative or its salt, and a skin external composition containing the same. More particularly, the invention relates to a sesamol derivative or its salt, which consists of sesamol and 3-aminopropane phosphoric acid, linked with each other by a phosphoric acid diester bond, and can be degraded into sesamol and 3-aminopropane phosphoric acid by enzymes present on the skin so as to simultaneously show the physiological activities of sesamol and 3-aminopropane phosphoric acid, as well as a preparation method thereof and a skin external composition containing the same.
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Page/Page column 5

(2009/05/28)

Improved solvent-free Dakin oxidation protocol
A solvent-free Dakin reaction with mCPBA was accomplished with various aromatic aldehydes, resulting in an easy and improved methodology for the preparation of corresponding phenols. 3,4-Methylenedioxyphenol, 3,4-dimethoxyphenol, 4-methoxyphenol, 4-chlorophenol, and other functionalized phenols were obtained in high yields from the corresponding aromatic aldehydes in a few minutes. This new methodology represents an efficient alternative for this important synthetic conversion. Copyright Taylor & Francis Group, LLC.
Da Silva, Emerson Teixeira,Camara, Celso Amorim,Antunes,Barreiro, Eliezer J.,Fraga, Carlos A. M.
p. 784 - 788
(2008/09/16)

A facile two-step synthesis of 2-arylbenzofurans based on the selective cross McMurry couplings
(Chemical Equation Presented) A novel two-step synthesis of 2-arylbenzofurans has been developed. It involves a selective cross McMurry coupling of a salicylaldehyde or substituted salicylaldehyde with an aromatic aldehyde and a sequential oxidative cyclization of the resulting ortho-vinylphenols. Utilizing this synthetic protocol, a variety of 2-arylbenzofurans including cicerfuran (5) have been efficiently synthesized.
Duan, Xin-Fang,Zeng, Jing,Zhang, Zhan-Bin,Zi, Guo-Fu
p. 10283 - 10286
(2008/04/05)

Synthetic studies on Ecteinascidin-743: synthesis of building blocks through Sharpless asymmetric dihydroxylation and aza-Michael reactions
A practical and an efficient synthesis of three building blocks of tetrahydroisoquinoline alkaloid Ecteinascidin-743 was accomplished, starting from readily available piperonal, 2-methyl anisole, and veratraldehyde. A combination of Vilsmeier-Haack reaction and Sharpless asymmetric dihydroxylation was employed for the synthesis of building blocks A and B whereas a Heck reaction in PEG-2000 and aza-Michael reactions were employed for the synthesis of building block C.
Chandrasekhar,Reddy, N. Ramakrishna,Rao, Y. Srinivasa
p. 12098 - 12107
(2007/10/03)

SESAMOL DERIVATIVES OR THEIR SALTS, THE PROCESS FOR PREPARING THE SAME, AND THE SKIN EXTERNAL COMPOSITION CONTAINING THE SAME
The present invention relates to a sesamol derivative or its salt, and a skin external composition containing the same. More particularly, the invention relates to a sesamol derivative or its salt, which consists of sesamol and 3-aminopropane phosphoric acid, linked with each other by a phosphoric acid diester bond, and can be degraded into sesamol and 3-aminoρropane phosphoric acid by enzymes present on the skin so as to simultaneously show the physiological activities of sesamol and 3-aminoproρane phosphoric acid, as well as a preparation method thereof and a skin external composition containing the same.
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Page/Page column 15; Fig. 1

(2008/06/13)

Synthesis of new (±) pterocarpans by Heck oxyarylation
Among a wide variety of synthetic routes to pterocarpan prototypes, a mild approach uses a reaction known as Heck oxyarylation. This method involves a reaction between 2H-chromenes and 2-chloromercuriophenols in the presence of Li2PdCl4. 2005 Springer Science+Business Media, Inc.
Sa E Sant'Anna,Evangelista,Alves,Raslan
p. 385 - 387
(2007/10/03)

Ti(III) chloride: A novel reagent for the chemoselective deprotection of tetrahydropyranyl ethers
Ti(III) chloride was found to be an effective catalyst for the deprotection of tetrahydropyranyl ethers of alcohols and phenols at an ambient temperature. Allyl ether, benzyl ether, tert-butyl-diphenylsilyl (TBDPS) ether, p-toluenesulfonate ester and isomerizable double bond were found to be compatible under the reaction conditions.
Semwal, Abha,Nayak, Sandip K.
p. 71 - 74
(2007/10/03)

PROCESS FOR PREPARING ALKOXY- AND ARYLOXY-PHENOLS
Process for preparing alkoxy- and aryloxy-phenols, comprising oxidizing the ketone of formula (I) with peracids to give the corresponding ester of formula (II) which is then hydrolysed to give the corresponding aryloxy- or alkoxy-phenol.
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Page 13

(2008/06/13)

HYDROXYLATION PROCESS FOR AROMATIC COMPOUNDS CONTAINING A DIOXA- HETEROCYCLIC SYSTEM
Process for the hydroxylation of aromatic compounds containing a dioxa-heterocyclic system which comprises directly hydroxylating said compounds with hydrogen peroxide in; the presence of a zeolitic catalyst having the general formula: xTi02'(1 -x)Si02 wherein x is i a number ranging from 0.0001 to 0.04.
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Page 7-8

(2008/06/13)

Phenol radical cations and phenoxyl radicals in electron transfer from the natural phenols sesamol, curcumin and trolox to the parent radical cations of 1-chlorobutane
The free electron transfer from sesamol, curcumin and trolox to solvent (1-chlorobutane) radical cations was studied. The solutes (ArOH) react with BuCl.+ at diffusion-controlled rates (～1010dm 3mol-1s-1/s
Joshi,Naumov,Kapoor,Mukherjee,Hermann,Brede
p. 665 - 674
(2007/10/03)

Improving the Dakin reaction by using an ionic liquid solvent
The oxidation of aromatic aldehydes to phenols (Dakin reaction) has been demonstrated to proceed readily on both activated and non-activated aldehydes in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMI][PF6], 1) with high selectivity, easy product separation and excellent chemical yields.
Zambrano, Jorge L.,Dortab, Romano
p. 1545 - 1546
(2007/10/03)

Preliminary structure-antiangiogenic activity relationships of 4-senecioyloxymethyl-6,7-dimethoxycoumarin.
Through a systematic modification of the novel angiogenesis inhibitor 4-senecioyloxymethyl-6,7-dimethoxycoumarin (1) we found that a 6,7-dimethoxy moiety is important for bioactivity of 1. Replacement of the lactone functionality in coumarin 1 by an amide decreased its activity. By substitution of the senecioyl chain with various cinnamoyl groups we discovered 6d, bearing a 4-methoxycinnamoyl instead of senecioyl side chain, with inhibitory activity in HUVEC tube formation assay enhanced by one order of magnitude compared to 1. We have also synthesized compound 12, an analogue of 6d, with equipotency and improved water solubility.
Nam, Nguyen-Hai,Kim, Yong,You, Young-Jae,Hong, Dong-Ho,Kim, Hwan-Mook,Ahn, Byung-Zun
p. 2345 - 2348
(2007/10/03)

Method of producing sesamol formic acid ester and sesamol
Heliotropin is oxidized with a percarboxylic acid in the presence of formic acid and an optionally added organic solvent, to thereby produce sesamol at high efficiency while suppressing by-production of heliotropic acid.
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Page 5

(2008/06/13)

A mild and selective cleavage of p-methoxybenzyl Ethers by CBr4-MeOH
p-Methoxybenzyl ethers were selectively deprotected to the corresponding alcohols and phenols in high yields by CBr4 in refluxing methanol under neutral reaction conditions.
Yadav,Reddy, B. V. Subba
p. 566 - 567
(2007/10/03)

Hydrogen peroxide/boric acid: An efficient system for oxidation of aromatic aldehydes and ketones to phenols
Hydrogen peroxide activated by boric acid in the presence of sulfuric acid has been shown to be an efficient oxidizing system for direct conversion of aromatic aldehydes and ketones to phenols.
Roy, Amrita,Reddy,Mohanta, Pramod K.,Ila,Junjappa
p. 3781 - 3791
(2007/10/03)

Palladium/P(t-Bu)3-catalyzed synthesis of aryl t-butyl ethers and application to the first synthesis of 4-chlorobenzofuran
Pd/P(t-Bu)3 catalyzed reaction of aryl halides with sodium t-butoxide effectively to give aryl t-butyl ethers. The high catalytic activity realized the formation of aryl t-butyl ethers from not only electron-deficient aryl halides but also electron-rich aryl halides. Moreover, the first synthesis of 4-chlorobenzofuran was attained utilizing the selective mono-t-butoxylation of aryl dihalide.
Watanabe, Makoto,Nishiyama, Masakazu,Koie, Yasuyuki
p. 8837 - 8840
(2007/10/03)

Microwave assisted selective cleavage of sulfonates and sulfonamides in dry media
A simple and efficient method for the cleavage of Sulfonates and Sulfonamides has been achieved for the first time under microwave irradiation conditions using KF-Al2O3.
Sabitha, Gowravaram,Abraham, Sunny,Reddy, B. V. Subba,Yadav
p. 1745 - 1746
(2007/10/03)