- Discovery of new benzhydrol biscarbonate esters as potent and selective apoptosis inducers of human melanomas bearing the activated ERK pathway: SAR studies on an ERK MAPK signaling modulator, ACA-28
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The recent discovery that an ERK signaling modulator [ACA-28 (2a)] preferentially kills human melanoma cell lines by inducing ERK-dependent apoptosis has generated significant interest in the field of anti-cancer therapy. In the first SAR study on 2a, here, we successfully developed candidates (2b, 2c) both of which induce more potent and selective apoptosis towards ERK-active melanoma cells than 2a, thus revealing the structural basis for inducing the ERK-dependent apoptosis and proposing the therapeutic prospect of these candidates against ERK-dependent cancers represented by melanoma.
- Satoh, Ryosuke,Hamada, Naoya,Yamada, Ami,Kanda, Yuki,Ishikawa, Fumihiro,Takasaki, Teruaki,Tanabe, Genzoh,Sugiura, Reiko
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- Visible-Light-Triggered C-C and C-N Bond Formation by C-S Bond Cleavage of Benzylic Thioethers
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The cleavage of sulfidic C-S bonds under visible-light irradiation was harnessed to generate carbocations under neutral conditions and synthesize valuable di- and triarylalkanes as well as benzyl amines. To this end, photoredox catalysis and direct photoinduced C-S bond cleavage are used as complementary approaches and participate in the versatility of the general strategy. Extensive mechanistic studies have demonstrated the diversity of the reaction mechanism at work in these different reactions.
- Lanzi, Matteo,Merad, Jérémy,Boyarskaya, Dina V.,Maestri, Giovanni,Allain, Clémence,Masson, Géraldine
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supporting information
p. 5247 - 5250
(2018/09/13)
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- Chiral phosphoric acid catalyzed asymmetric addition of naphthols to para -quinone methides
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An asymmetric addition of naphthols to in situ generated para-quinone methides catalyzed by a chiral phosphoric acid is described. A range of useful triarylmethanes can be generated from stable general para-hydroxybenzyl alcohols with good efficiency and enantioselectivity.
- Wong, Yuk Fai,Wang, Zhaobin,Sun, Jianwei
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supporting information
p. 5751 - 5754
(2016/07/06)
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- A general Br?nsted acid-catalyzed allylation of benzhydryl alcohols
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Efficient Br?nsted acid-catalyzed allylation of benzhydryl alcohols has been developed. The reaction occurs within 5?min in the presence of sub-stoichiometric amounts of HBF4·OEt2to afford the desired products in good to excellent yields. A variety of functional groups were tolerated under the developed conditions including amides, aldehydes, hydroxyl and carboxylic acid.
- Orizu, Ifedi,Bolshan, Yuri
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supporting information
p. 5798 - 5800
(2016/12/03)
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- Br?nsted Acid-Catalyzed Reactions of Trifluoroborate Salts with Benzhydryl Alcohols
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Br?nsted acid-catalyzed carbon-carbon bond forming methodology using potassium alkynyl- and alkenyltrifluoroborate salts has been developed. Organotrifluoroborates react with benzhydryl alcohols to afford a broad range of alkynes and alkenes in good to excellent yields. This protocol features good atom economy because organotrifluoroborate salts and alcohols react in a 1:1 ratio. Furthermore, a variety of unprotected functional groups were tolerated under the developed conditions, including amide, aldehyde, free hydroxyl, and carboxylic acid.
- Fisher, Kayla M.,Bolshan, Yuri
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p. 12676 - 12685
(2016/01/09)
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- Direct electrosynthesis of ketones from benzylic methylenes by electrooxidative C-H activation
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Electrify your chemistry! Direct electrosynthesis of ketones from benzylic methylenes in an undivided cell was realized in moderate to good yields (see scheme). In this electrosynthesis, electrons instead of conventional oxidants and catalysts are employed to make the reaction environmentally benign. Moreover, the reaction intermediate radical was detected by ESR spectroscopy and the reaction mechanism was clarified.
- Meng, Li,Su, Jihu,Zha, Zhenggen,Zhang, Li,Zhang, Zhenlei,Wang, Zhiyong
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supporting information
p. 5542 - 5545
(2013/05/23)
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- Synthesis of fluorenone derivatives through Pd-catalyzed dehydrogenative cyclization
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Palladium-catalyzed dual C-H functionalization of benzophenones to form fluorenones by oxidative dehydrogenative cyclization is reported. This method provides a concise and effective route toward the synthesis of fluorenone derivatives, which shows outstanding functional group compatibility.
- Li, Hu,Zhu, Ru-Yi,Shi, Wen-Juan,He, Ke-Han,Shi, Zhang-Jie
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supporting information
p. 4850 - 4853,4
(2012/12/12)
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- Palladium catalyzed isomerization of alkenes: A pronounced influence of an o-phenol hydroxyl group
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A novel palladium catalyzed isomerization of alkenes has been found, where an ortho-phenol hydroxyl group has a pronounced influence on the isomerization.
- Fan, Jinmin,Wan, Changfeng,Wang, Qiang,Gao, Linfeng,Zheng, Xiaoqi,Wang, Zhiyong
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supporting information; experimental part
p. 3168 - 3172
(2011/02/25)
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- A metal-free catalytic system for the oxidation of benzylic methylenes and primary amines under solvent-free conditions
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Iodine-pyridine-tert-butylhydroperoxide is developed as a green and efficient catalytic system for the oxidation of benzylic methylenes to ketones and primary amines to nitriles. The reaction conditions are quite mild and environmentally benign, no transition metals, organic solvents or hazard reagents being needed. The oxidation of benzylic methylenes gave the corresponding ketones in excellent yields with complete chemoselectivity, while the oxidation of primary amines was complete in several minutes, affording various nitriles in moderate to good yields.
- Zhang, Jintang,Wang, Zhentao,Wang, Ye,Wan, Changfeng,Zheng, Xiaoqi,Wang, Zhiyong
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supporting information; scheme or table
p. 1973 - 1978
(2010/06/15)
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- Acetoxybenzhydrols as highly active and stable analogues of 1′S-1′-acetoxychavicol, a potent antiallergic principal from Alpinia galanga
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Through SAR studies on 1′S-1′-acetoxychavicol acetate (1) against Type I antiallergic activity by indexing release of β-hexosaminidase, a marker of antigen-IgE-mediated degranulation in RBL-2H3 cells, more stable and potent analogue, 4-(methoxycarbonyloxy
- Yasuhara, Tomohisa,Manse, Yoshiaki,Morimoto, Takayuki,Qilong, Wang,Matsuda, Hisashi,Yoshikawa, Masayuki,Muraoka, Osamu
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scheme or table
p. 2944 - 2946
(2010/01/16)
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- Chemistry of photogenerated α-phenyl-substituted o-, m-, and p-quinone methides from phenol derivatives in aqueous solution
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The enhanced photochemical reactivity of o-substituted phenols in its propensity to give o-quinone methide (o-QM) intermediates via excited state intramolecular proton transfer (ESIPT) was uncovered by Keith Yates as part of his now classic studies of photohydration of aromatic alkenes, alkynes, and related compounds. Photogeneration of QMs and the study of their chemistry along with potential biological applications are the focus of many groups. In this work, photochemical precursors to o-, m-, and p-QMs based on substituted phenols (hydroxybenzyl alcohols) and related compounds have been studied in aqueous solution as a function of pH and water content. The focus will be on QMs that are stabilized by an a-phenyl substituent, which enhances quantum yields for their formation, with the resulting QMs having longer lifetimes and easier to detect. Noteworthy is that all QM isomers can. be photogenerated with the o and m isomers being the most efficient, consistent with the Zimmerman "ortho-meta" effect. m-QMs have formal non-Kekule structures, and although they can be routinely photogenerated, are found to be most reactive. One m-QM was found, to undergo a photocondensation reaction at high pH giving rise to m-substituted oligomers. The mechanism, of QM formation in aqueous solution is believed to involve singlet excited phenols that undergo adiabatic deprotonation to give the corresponding photoexcited phenolate ion, which subsequently expels the hydroxide ion (photodehydroxylation). A pathway involving direct loss of water for the o-isomers is also possible in organic solvents.
- Diao, Li,Wan, Peter
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p. 105 - 118
(2008/09/18)
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- Wet THF as a suitable solvent for a mild and convenient reduction of carbonyl compounds with NaBH4
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NaBH4 in wet THF can readily reduce varieties of carbonyl compounds such as aldehydes, ketones, conjugated enones, acyloins, and α-diketones to their corresponding alcohols in good to excellent yields. Reduction reactions were performed at room temperature or under reflux condition. In addition, the chemoselective reduction of aldehydes over ketones was accomplished successfully with this reducing system.
- Zeynizadeh, Behzad,Behyar, Tarifeh
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p. 307 - 315
(2007/10/03)
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- Carbinol derivatives via rhodium-catalyzed addition of potassium trifluoro(organo)borates to aldehydes
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Reaction of potassium aryltrifluoroborates with aldehydes, in the presence of a rhodium catalyst, afforded carbinol derivatives in high yields under mild aqueous conditions; this efficient reaction proved to be general, allowing the production of highly hindered diarylmethanols and aliphatic aldehydes were also reactive under these conditions. The Royal Society of Chemistry 2005.
- Pucheault, Mathieu,Darses, Sylvain,Genet, Jean-Pierre
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p. 4714 - 4716
(2007/10/03)
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- Flash photolytic generation and study of p-quinone α-phenylmethide and p-quinone α,α-diphenylmethide in aqueous solution
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p-Quinone α-phenylmethide (7) and p-quinone α,α- diphenylmethide (8) were generated by flash photolytic dehydration of p-hydroxy-α-phenylbenzyl alcohol (9, R1 =Ph, R2 = H) and p-hydroxy-α,α-diphenylbenzyl alcohol (9, R1 = R 2 = Ph) respectively, and rates of their decay were measured in aqueous perchloric acid and sodium hydroxide solutions and also as in acetic acid, biphosphate ion, tris(hydroxymethyl)methylammonium ion, ammonium ion and bicarbonate ion buffers. The rate profiles for the hydration of these quinone methides that these data provide show hydronium ion and hydroxide ion-catalyzed regions and also 'uncatalyzed' water reactions, with saturation of hydronium ion catalysis in dilute solution for the diphenyl-substituted substrate but only in concentrated acid solution for the less basic monophenyl substrate. Both substrates also give inverse hydronium ion isotope effects (k H+/kD+ 1). These results show that the hydronium ion-catalyzed reactions occur by rapid pre-equilibrium protonation of the quinone methide on its carbonyl oxygen atom followed by rate-determining capture of the benzyl-type carbocation thus formed by water. Phenyl substitution retards the rate of hydration and also reduces the acidity constant of the quinone methide conjugate acid. The molecular basis of these substituent effects is discussed. Copyright
- Chang,Kresge,Zhan,Zhu
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p. 579 - 585
(2007/10/03)
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- Reduction of carbonyl compounds with NaBH4 under ultrasound irradiation and aprotic condition
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A variety of carbonyl compounds are reduced to their corresponding alcohols with sodium borohydride under ultrasound irradiation and aprotic condition. Reduction reactions are performed in THF at room temperature or under reflux condition. The product alcohols were obtained in good to excellent yields. The chemoselective reduction of aldehydes over ketones was achieved successfully with this system.
- Zeynizadeh, Behzad,Yahyaei, Saiedeh
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p. 704 - 710
(2007/10/03)
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- Halogen-magnesium exchange of m- and p-iodo or bromo-arenes bearing ortho-directing groups through ate complexes
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m- or p-Iodinated, or brominated ω-phenoxyalcohols and phenols as well as halogenated indoles were subjected to halogen-magnesium exchange reactions with isopropyl magnesium bromide (iPrMgBr) or isopropyl magnesium di-n-butyl lithium ate comple
- Xu, Jiayi,Jain, Nareshkumar,Sui, Zhihua
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p. 6399 - 6402
(2007/10/03)
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- Mild and efficient method for reduction of aldehydes and ketones with NaBH4 in the presence of Dowex1-x8
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Various aldehydes and ketones are reduced efficiently to alcohols with NaBH4/Dowex1-x8.
- Zeynizadeh, Behzad,Shirini, Farhad
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p. 335 - 339
(2007/10/03)
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- Modified hydroborate agent: (2,2′-bipyridyl)(tetrahydroborato)zinc complex, [Zn(BH4)2(bpy)], as a new, stable, efficient ligand-metal hydroborate and chemoselective reducing agent
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(2,2′-Bipyridyl)(tetrahydroborato)zinc complex, [Zn(BH4)2(bpy)], is a new white stable compound which has been used for efficient reduction of variety of carbonyl compounds such as aldehydes, ketones, acyloins, α-diketones and α, β-unsaturated carbonyl compounds (1,2-reduction) to their corresponding alcohols in acetonitrile at room temperature. Excellent chemoselectivity was also observed for the reduction of aldehydes over ketones with this reducing agent.
- Zeynizadeh, Behzad
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p. 317 - 326
(2007/10/03)
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- Titanyl Acetylacetonate as an Efficient Catalyst for a Mild and Convenient Reduction of Carbonyl Compounds with NaBH4 under Aprotic Condition
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Titanyl acetylacetonate, TiO(acac)2, is used as an efficient catalyst for the reduction of carbonyl compounds with sodium borohydride under aprotic condition. Reduction reactions are performed in CH3CN and THF. The corresponding alcohols are obtained in high to excellent yields and the chemoselective reduction of aldehydes over ketones is achieved successfully.
- Zeynizadeh, Behzad
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p. 1220 - 1226
(2007/10/03)
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- Chemoselective control of hydrogenation among aromatic carbonyl and benzyl alcohol derivatives using Pd/C(en) catalyst
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The hydrogenolysis of aromatic ketones and aldehydes quite smoothly give the corresponding methylene compounds via the formation of the intermediary benzyl alcohols in the presence of Pd/C as a catalyst. Therefore, it is extremely difficult to isolate the intermediary benzyl alcohol selectively. This paper describes a mild and chemoselective hydrogenation method of an aromatic carbonyl compound to benzyl alcohol using the 10% Pd/C(en) catalyst and its application to the chemoselective deacetoxylation reaction at the benzylic position in the presence of the benzyl alcohol functionality within the molecule.
- Hattori, Kazuyuki,Sajiki, Hironao,Hirota, Kosaku
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p. 4817 - 4824
(2007/10/03)
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- Functionalised organotitanium compounds: From lithium to titanium intermediates in chemoselective reactions with carbonyl compounds
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The reaction of functionalised organolithium compounds 1 with an equimolecular mixture of two carbonyl compounds in the presence of 2 equiv. of triisopropoxytitanium chloride can discriminate between aldehyde and ketone, the process being selective for al
- Pastor, Isidro M,Yus, Miguel
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p. 2365 - 2370
(2007/10/03)
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- An alternate preparation of thioester resin linkers for solid-phase synthesis of peptide C-terminal thioacids
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An alternative preparation of thioester resin linkers for solid-phase synthesis of peptide C-terminal thioacids is presented. (C) 2000 Elsevier Science Ltd.
- Goldstein, Alex S.,Gelb, Michael H.
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p. 2797 - 2800
(2007/10/03)
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- Easy and partial hydrogenation of aromatic carbonyls to benzyl alcohols using Pd/C(en)-catalyst
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Although 10% Pd/C catalyzed hydrogenolysis of aromatic ketones and aldehydes readily affords methylene compounds via intermediary benzyl alcohols, the employment of 10% Pd/C-ethylenediamine complex [Pd/C(en)] as a catalyst eased the formation of benzyl alcohols.
- Sajiki, Hironao,Hattori, Kazuyuki,Hirota, Kosaku
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p. 4043 - 4044
(2007/10/03)
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- DEOXYGENATION OF ALDEHYDES AND KETONES WITH SODIUM CYANOBOROHYDRIDE
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Treatment of hydroxy-substituted aromatic aldehydes and ketones with sodium cyanoborohydride yields the corresponding methylene compounds under conditions which favor intermediate carbonium ion formation.
- Elliger, Carl A.
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p. 1315 - 1324
(2007/10/02)
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- Voltammetric Studies of 3-Bromo-4-hydroxybenzophenone
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Electrochemical reduction of 3-bromo-4-hydroxybenzophenone has been carried out in aqueous and 50percent aq ethanolic media in the presence of different supporting electrolytes using cyclic voltammetry, chronoamperometry and chronopotentiometry at hanging
- Sivakumar, A.,Jayarama Reddy, S.
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p. 732 - 735
(2007/10/02)
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- Cyclic Voltammetry and Chronoamperometry of Some Substituted Benzophenones
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Electrochemical reduction of p-hydroxy-, p-amino-, p-methyl- and p-phenyl-benzophenones has been investigated in borax buffer of pH 9.2 using cyclic voltammetry and chronoamperometry at hanging mercury drop electrode.The nature of the two-electron reduction is discussed.Peak potentials are correlated to Hammett substituent constants.Diffusion coefficients and heterogeneous rate constants are reported.
- Sivakumar, A.,Jayarama Reddy, S.,Krishnan, V. R.
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p. 800 - 802
(2007/10/02)
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