cas 33524-31-1, 2,5-DIMETHOXYBENZYL ALCOHOL

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1-Trifluoromethylisoquinolines from α-Benzylated Tosylmethyl Isocyanide Derivatives in a Modular Approach
The preparation of various 1-trifluoromethylisoquinolines from α-benzylated tosylmethyl isocyanide derivatives and the commercial Togni reagent using a radical cascade is reported. The starting isocyanides are readily prepared in a modular sequence from commercial tosylmethyl isocyanide via sequential double α-alkylation, and the radical reaction proceeds under mild conditions with high efficiency without any transition-metal catalyst via electron catalysis. This valuable protocol has been successfully applied to the total synthesis of CF3-mansouramycin B.
Wang, Lin,Studer, Armido
p. 5701 - 5704
(2017)
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Selective Deprotection of Esters Using Magnesium and Methanol
The use of magnesium metal in methanol for the deprotection of alkyl esters is described.This mild reagent also provides good to excellent selectivity to cleave different esters.The order of reactivity of this reagent towards acyl cleavages was found to be: p-nitrobenzoate > acetate > benzoate > pivaliate >> trifluoroacetamide.
Xu, Yao-Chang,Lebeau, Elaine,Walker, Clint
p. 6207 - 6210
(1994)
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Synthesis of new iron-NHC complexes as catalysts for hydrosilylation reactions
A series of new piano-stool iron(II) complexes comprising N-heterocyclic carbene ligands [Fe(Cp)(CO)2(NHC)]I (NHC = 1,3-disubstituted imidazolidin-2-ylidene) have been synthesized and analyzed by 1H NMR, 13C NMR, IR, elemental analysis and mass spectrometric techniques. These compounds were easily prepared from the reaction of disubstituted imidazolidin-2-ylidene with [FeI(Cp)(CO)2] in toluene at room temperature. These complexes were tested in the catalytic hydrosilylation reaction of aldehydes and ketones with phenylsilane in solvent-free conditions. After a basic hydrolysis step, the corresponding alcohols were obtained in good yields. Copyright
Demir, Serpil,Goekce, Yasemin,Kaloglu, Nazan,Sortais, Jean-Baptiste,Darcel, Christophe,Oezdemir, Ismail
p. 459 - 464
(2013)
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Selective deprotection of alkyl esters using magnesium methoxide
The use of magnesium methoxide for the deprotection of alkyl esters is described. This mild reagent provides a good method to cleave esters efficiently and more importantly, allows for effective differentiation between two different esters. The order of the reactivity of this reagent towards acyl cleavages was found to be: p-nitrobenzoate > acetate > benzoate > pivaloate >> acetamide.
Xu, Yao-Chang,Bizuneh, Amsalu,Walker, Clint
p. 455 - 458
(1996)
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Preparation method of 2,5-dimethoxyphenylacetic acid
The invention belongs to the technical field of drug synthesis, and particularly relates to a preparation method of 2,5-dimethoxyphenylacetic acid, wherein the method comprises the following steps: A,reacting 1,4-dimethoxybenzene in a formylation system to obtain 2,5-dimethoxybenzaldehyde; B, reacting the 2,5-dimethoxybenzaldehyde obtained in the step A with a reducing agent, extracting a reaction system, then combining organic phases, drying, concentrating under reduced pressure and distilling a crude product to obtain 2,5-dimethoxybenzyl alcohol; C, reacting the 2,5-dimethoxybenzyl alcoholobtained in the step B with a bromination reagent to obtain 2-bromomethyl-1,4-dimethoxybenzene; and D, reacting the 2-bromomethyl-1,4-dimethoxybenzene obtained in the step C with magnesium or butyl lithium and carbon dioxide in a solvent to obtain the 2,5-dimethoxyphenylacetic acid. The yield and the total yield of the 2,5-dimethoxyphenylacetic acid obtained by the method disclosed by the invention are both higher than those of 2,5-dimethoxyphenylacetic acid synthesized by a Willegerdt-Kindler method.
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Paragraph 0024; 0027; 0032; 0035; 0040; 0043; 0047; 0050

(2021/02/06)

Discovery, synthesis and anti-atherosclerotic activities of a novel selective sphingomyelin synthase 2 inhibitor
The sphingomyelin synthase 2 (SMS2) is a potential target for pharmacological intervention in atherosclerosis. However, so far, few selective SMS2 inhibitors and their pharmacological activities were reported. In this study, a class of 2-benzyloxybenzamides were discovered as novel SMS2 inhibitors through scaffold hopping and structural optimization. Among them, Ly93 as one of the most potent inhibitors exhibited IC50 values of 91 nM and 133.9 μM against purified SMS2 and SMS1 respectively. The selectivity ratio of Ly93 was more than 1400-fold for purified SMS2 over SMS1. The in vitro studies indicated that Ly93 not only dose-dependently diminished apoB secretion from Huh7 cells, but also significantly reduced the SMS activity and increased cholesterol efflux from macrophages. Meanwhile, Ly93 inhibited the secretion of LPS-mediated pro-inflammatory cytokine and chemokine in macrophages. The pharmacokinetic profiles of Ly93 performed on C57BL/6J mice demonstrated that Ly93 was orally efficacious. As a potent selective SMS2 inhibitor, Ly93 significantly decreased the plasma SM levels of C57BL/6J mice. Furthermore, Ly93 was capable of dose-dependently attenuating the atherosclerotic lesions in the root and the entire aorta as well as macrophage content in lesions, in apolipoprotein E gene knockout mice treated with Ly93. In conclusion, we discovered a novel selective SMS2 inhibitor Ly93 and demonstrated its anti-atherosclerotic activities in vivo. The preliminary molecular mechanism-of-action studies revealed its function in lipid homeostasis and inflammation process, which indicated that the selective inhibition of SMS2 would be a promising treatment for atherosclerosis.
Li, Yali,Huang, Taomin,Lou, Bin,Ye, Deyong,Qi, Xiangyu,Li, Xiaoxia,Hu, Shuang,Ding, Tingbo,Chen, Yan,Cao, Yang,Mo, Mingguang,Dong, Jibin,Wei, Min,Chu, Yong,Li, Huiti,Jiang, Xian-Cheng,Cheng, Nengneng,Zhou, Lu
supporting information
p. 864 - 882
(2019/01/04)

CD16A BINDING AGENTS AND USES THEREOF
Among other things, the present disclosure provides compounds, compositions thereof, and methods of using the same. In some embodiments, compounds of the present disclosure bind to Fc receptors, e.g., CD16a. In some embodiments, compounds of the present disclosure are useful for treating various conditions, disorders or diseases including cancer.
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Paragraph 00656

(2019/07/20)

IRIDIUM-BASED CATALYSTS FOR HIGHLY EFFICIENT DEHYDROGENATION AND HYDROGENATION REACTIONS IN AQUEOUS SOLUTION AND APPLICATIONS THEREOF
A series of iridium-based catalysts for dehydrogenation of formic acid, and hydrogenation using formic acid as the hydrogen source, and the process using the catalyst(s) to produce hydrogen gas from formic acid solution, or to reduce aldehydes using formic acid, are disclosed and claimed. More specifically, the present invention relates to a group of pentamethylcyclopentadienyl (Cp*) iridium complexes with different Ν,Ν-bidentate ligands that catalyze dehydrogenation from formic acid, and chemo-selective hydrogenation of aldehydes, in the aqueous solution system in a highly efficient, and long life-time manner.
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Page/Page column 13-14

(2018/11/22)

3, 5-disubstituted hydantoin compound as well as preparation method and application thereof
The invention provides a 3, 5-disubstituted hydantoin compound as well as a preparation method and an application thereof. The structure of the compound is shown in formula I in the description. The application of the 3, 5-disubstituted hydantoin compound shown in the formula I or solvates, hydrates or salts of the compound in preparation of medicines for treating Alzheimer's disease, vascular dementia and other dementia diseases with memory impairment also belongs to the protection scope. Animal experiments prove that the compound has the effect of saving memory of animal models, has high safety, does not have mutagenicity, can stay in blood for several hours after oral administration and intravenous injection, and can enter the brain.
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Paragraph 0042; 0073; 0074; 0075; 0076

(2018/10/19)

Iridium-catalyzed highly efficient chemoselective reduction of aldehydes in water using formic acid as the hydrogen source
A water-soluble highly efficient iridium catalyst is developed for the chemoselective reduction of aldehydes to alcohols in water. The reduction uses formic acid as the traceless reducing agent and water as a solvent. It can be carried out in air without the need for inert atmosphere protection. The products can be purified by simple extraction without any column chromatography. The catalyst loading can be as low as 0.005 mol% and the turn-over frequency (TOF) is as high as 73 800 mol mol-1 h-1. A wide variety of functional groups, such as electron-rich or deficient (hetero)arenes and alkenes, alkyloxy groups, halogens, phenols, ketones, esters, carboxylic acids, cyano, and nitro groups, are all well tolerated, indicating excellent chemoselectivity.
Yang, Zhanhui,Zhu, Zhongpeng,Luo, Renshi,Qiu, Xiang,Liu, Ji-Tian,Yang, Jing-Kui,Tang, Weiping
supporting information
p. 3296 - 3301
(2017/07/28)

Toward the Stereoselective Synthesis of Arthrobotrisin A: Fragment Synthesis and Coupling Studies
A route towards the stereocontrolled synthesis of arthrobotrisin A based on a Nozaki-Hiyama-Kishi (NHK) coupling strategy was developed. Highlights of the fragment synthesis include enzyme-catalyzed kinetic resolution, Negishi carbometalation-iodination, quinone formation through oxidation with hypervalent iodine, chiral oxazaborolidine-catalyzed asymmetric Diels-Alder reaction with cyclopentadiene, regio- and stereoselective epoxidation, Noyori reduction, retro-Diels-Alder reaction, diastereoselective Luche reduction, and, finally, a Nozaki-Hiyama-Kishi (NHK) coupling of the vinyl iodide fragment.
Kumar, Rayala Naveen,Kumar, Nandigama Satish,Meshram, Harshadas M.
supporting information
p. 1046 - 1050
(2017/05/19)

Approach to Merosesquiterpenes via Lewis Acid Catalyzed Nazarov-Type Cyclization: Total Synthesis of Akaol A
A Lewis acid catalyzed Nazarov-type cyclization of arylvinylcarbinol has been developed for the asymmetric synthesis of carbotetracyclic core of merosesquiterpenes. The reaction works only in the presence of 2 mol % of Sn(OTf)2 and Bi(OTf)3 in dichloroethane under elevated temperature. The methodology offers the synthesis of a variety of enantioenriched arylvinylcarbinols from commercially available (3aR)-sclareolide 9 in six steps with an eventual concise total synthesis of marine sesquiterpene quinol, akaol A (1a).
Kakde, Badrinath N.,Kumar, Nivesh,Mondal, Pradip Kumar,Bisai, Alakesh
supporting information
p. 1752 - 1755
(2016/05/19)

Self-assembled near-infrared dye nanoparticles as a selective protein sensor by activation of a dormant fluorophore
Design of selective sensors for a specific analyte in blood serum, which contains a large number of proteins, small molecules, and ions, is important in clinical diagnostics. While metal and polymeric nanoparticle conjugates have been used as sensors, small molecular assemblies have rarely been exploited for the selective sensing of a protein in blood serum. Herein we demonstrate how a nonspecific small molecular fluorescent dye can be empowered to form a selective protein sensor as illustrated with a thiol-sensitive near-IR squaraine ( Sq) dye (λabs= 670 nm, λem= 700 nm). The dye self-assembles to form non fluorescent nanoparticles (Dh = 200 nm) which selectively respond to human serum albumin (HSA) in the presence of other thiol-containing molecules and proteins by triggering a green fluorescence. This selective response of the dye nanoparticles allowed detection and quantification of HSA in blood serum with a sensitivity limit of 3 nM. Notably, the Sq dye in solution state is nonselective and responds to any thiol-containing proteins and small molecules. The sensing mechanism involves HSA specifi c controlled disassembly of the Sq nanoparticles to the molecular dye by a noncovalent binding process and its subsequent reaction with the thiol moiety of the protein, triggering the green emission of a dormant fluorophore present in the dye. This study demonstrates the power of a self-assembled small molecular fluorophore for protein sensing and is a simple chemical tool for the clinical diagnosis of blood serum.
Anees, Palapuravan,Sreejith, Sivaramapanicker,Ajayaghosh, Ayyappanpillai
supporting information
p. 13233 - 13239
(2015/03/30)

Synthesis, in vitro antimycobacterial and antibacterial evaluation of IMB-070593 derivatives containing a substituted benzyloxime moiety
A series of novel IMB-070593 derivatives containing a substituted benzyloxime moiety and displaying a remarkable improvement in lipophilicity were synthesized and evaluated for their in vitro antimycobacterial and antibacterial activity. Our results reveal that the target compounds 19a-m have considerable Gram-positive activity (MIC: 0.008-32 μg/mL), although they are generally less active than the reference drugs against the Gram-negative strains. In particular, compounds 19h, 19j, 19k and 19m show good activity (MICs: 0.008-4 μg/mL) against all of the tested Gram-positive strains, including ciprofloxacin (CPFX)- and/or levofloxacin (LVFX)-resistant MSSA, MRSA and MSSE. Moreover, compound 19l (MIC: 0.125 μg/mL) is found to be 2-4 fold more active than the parent IMB070593, CPFX and LVFX against M. tuberculosis H37Rv ATCC 27294.
Wei, Zengquan,Wang, Jian,Liu, Mingliang,Li, Sujie,Sun, Lanying,Guo, Huiyuan,Wang, Bin,Lu, Yu
p. 3872 - 3893
(2013/06/05)

Multi-electron donor organic molecules containing hydroquinone methyl-ether as redox active units
Three hydroquinone dimethyl ether derivatives have been synthesized and characterized by X-ray diffraction. The electron donating properties were evaluated by using UV-vis spectroscopy, cyclic voltammetry and by ESR spectroscopy. The microcrystalline cation-radical salts of the three donor molecules were also isolated by using antimony pentachloride, a single electron Lewis acid oxidant.
Khandelwal, Manish,Hwang, In-Chul,Nair, Prakash Chandran R.,Lee, Jung-Woo
scheme or table
p. 1190 - 1198
(2012/07/14)

Synthesis and in vitro antibacterial activity of gemifloxacin derivatives containing a substituted benzyloxime moiety
A series of novel gemifloxacin (GMFX) derivatives containing a substituted benzyloxime moiety with remarkable improvement in lipophilicity were synthesized. The target compounds evaluated for their in vitro antibacterial activity against representative strains. Our results reveal that most of the target compounds have considerable potency against all of the tested Gram-positive strains including MRSA and MRSE (MIC: 90: 1 μg/mL) is 8-fold more active than GMFX, and 2-fold more active than GMFX and moxifloxacin against MRSE clinical isolates (MIC90: 4 μg/mL). Crown Copyright
Feng, Lianshun,Lv, Kai,Liu, Mingliang,Wang, Shuo,Zhao, Jing,You, Xuefu,Li, Sujie,Cao, Jue,Guo, Huiyuan
p. 125 - 136
(2012/11/07)

Synthesis and biological activity of pyridopyridazin-6-one p38α MAP kinase inhibitors. Part 2
This manuscript concludes the Structure Activity Relationship (SAR) on the pyridazinone scaffold and identifies a compound with subnanomolar p38α activity and 24 h coverage in the rat arthritis efficacy model.
Tynebor, Robert M.,Chen, Meng-Hsin,Natarajan, Swaminathan R.,O'Neill, Edward A.,Thompson, James E.,Fitzgerald, Catherine E.,O'Keefe, Stephen J.,Doherty, James B.
p. 5971 - 5975
(2012/11/07)

The first total synthesis and structural determination of antibiotics K1115 B1s (alnumycins)
K1115 B1, isolated from the broth of Streptomyces species, was found to be a mixture of stereoisomers. Authors synthesized all stereoisomers of K1115 B1 by convergent synthesis coupling a rhamnose derivative, an isobenzofuranone, and a chiral tetraol. Comparison of 1H NMR spectra and optical rotations made it clear that the absolute structures of K1115 B 1α (the major isomer) and K1115 B1β (the minor isomer) were (1R, 17S)- and (1R, 17R)-configurations, respectively. The optical rotations of the stereoisomers revealed that alnumycin, reported as the identical structure with K1115 B1, might be another mixture of stereoisomers.
Tatsuta, Kuniaki,Tokishita, Sonoko,Fukuda, Tomohiro,Kano, Takaaki,Komiya, Tadaaki,Hosokawa, Seijiro
scheme or table
p. 983 - 986
(2011/03/22)

Preparation of pillar[n]arenes by cyclooligomerization of 2,5-dialkoxybenzyl alcohols or 2,5-dialkoxybenzyl bromides
The facile and efficient preparation of pillar[n]arenes (n = 5 or 6) was achieved by cyclooligomerization of 2,5-dialkoxybenzyl alcohols or 2,5-dialkoxybenzyl bromides with an appropriate Lewis acid catalyst at room temperature. The mechanism for this cyclooligomerization is presumed to be a Friedel-Crafts alkylation.
Ma, Yingjie,Zhang, Zibin,Ji, Xiaofan,Han, Chengyou,He, Jiuming,Abliz, Zeper,Chen, Weixiang,Huang, Feihe
experimental part
p. 5331 - 5335
(2011/11/12)

De novo synthesis and lectin binding studies of unsaturated carba-pyranoses
Starting from branched para-benzoquinones a practical and highly flexible route is described for the preparation of unsaturated carbapyranoses. The potential of the synthesized galactose analogues to act as competitive inhibitors in lectin-carbohydrate interactions is investigated by means of Surface Plasmon Resonance (SPR) Spectroscopy.
Leermann, Timo,Block, Oliver,Podeschwa, Michael A. L.,Pfueller, Uwe,Altenbach, Hans-Josef
supporting information; experimental part
p. 3965 - 3974
(2010/09/17)

Efficient synthesis of (±)-parasitenone, a novel inhibitor of NF-κB
Dehydroxymethylepoxyquinomicin (DHMEQ, 1) is a novel nuclear factor-κB (NF-κB) inhibitor that inhibits DNA binding of NF-κB components including p65. To inspect its biological activity of 1, we synthesized parasitenone (3), possessing the common epoxycyclohexenone moiety of 1. Assessment of the inhibitory activity against NF-κB indicated that the epoxycyclohexenone moiety is the most essential element for the NF-κB inhibitory activity and the salicylic acid moiety may contribute the binding efficiency and specificity.
Saitoh, Tsuyoshi,Suzuki, Eriko,Takasugi, Arisa,Obata, Rika,Ishikawa, Yuichi,Umezawa, Kazuo,Nishiyama, Shigeru
scheme or table
p. 5383 - 5386
(2010/08/06)

2,5-Dihydroxybenzyl and (1,4-dihydroxy-2-naphthyl)methyl, novel reductively armed photocages for the hydroxyl moiety
(Chemical Equation Presented) Irradiation of alcohols, phenols, and carboxylic acids "caged" with the 2,5-dihydroxybenzyl group or its naphthalene analogue results in the efficient release of the substrate. The initial byproduct of the photoreaction, 4-hydroxyquinone-2-methide, undergoes rapid tautomerization into methyl p-quinone. The UV spectrum of the latter is different from that of the caging chromophore, thus permitting selective irradiation of the starting material in the presence of photochemical products. These photoremovable protecting groups can be armed in situ by the reduction of photochemically inert p-quinone precursors.
Kostikov, Alexey P.,Popik, Vladimir V.
p. 9190 - 9194
(2008/03/14)

On water and in air: Fast and highly chemoselective transfer hydrogenation of aldehydes with iridium catalysts
(Chemical Equation Presented) Water as solvent: A fast, selective, and high-yielding transfer hydrogenation of a wide range of aldehydes is achieved using IrIII catalysts containing simple ethylene-diamine (en) ligands (see scheme; Ts = p-toluenesulfonyl, TOF = turnover frequency). This procedure is suitable for aldehydes with a wide range of functional groups.
Wu, Xiaofeng,Liu, Jianke,Li, Xiaohong,Zanotti-Gerosa, Antonio,Hancock, Fred,Vinci, Daniele,Ruan, Jiwu,Xiao, Jianliang
p. 6718 - 6722
(2007/10/03)

Design, synthesis and biological evaluation of novel riccardiphenol analogs
A novel, facile, high yield, and less cumbersome synthesis of riccardiphenol analogs is described. The synthesized compounds were characterized and assessed for its in vitro activity in a panel of human cancer cell lines of differing origin: HuCCT-1, BxPC3, Panc-1, Mia-Paca, A431, Hep2, and HN006. HuCCT-1 was derived from an intrahepatic cholangiocarcinoma; BxPC3, Mia-Paca, and Panc-1 were derived from pancreatic cancers; A431 was derived from a vulvar epithelial carcinoma; and Hep2 and HN006 were derived from squamous cell carcinomas of the head and neck. The cytotoxicity of a newly developed riccardiphenol analog against human cancer cell lines was assessed. The cancer cells exhibited varying sensitivities to the compound, with IC50 values from 30 to 50 μM. This susceptibility was particularly interesting in the case of lines such as Hep2 and BxPC3 that are resistant to classic cytotoxic drugs as well as some targeted agents. These results demonstrate that the novel riccardiphenol analog has effective action against human-derived cancer cell in vitro.
Kumar, Srinivas K.,Amador, Maria,Hidalgo, Manuel,Bhat, Sujata V.,Khan, Saeed R.
p. 2873 - 2880
(2007/10/03)

NITROGENOUS CYCLIC KETONE DERIVATIVE, PROCESS FOR PRODUCING THE SAME, AND USE
A novel compound represented by the formula (I): wherein rings A and B each represents an optionally substituted aromatic ring, or rings A and B may be bonded to each other through linking between bonds or substituents thereof to form a ring; ring C represents a nitrogenous saturated heterocycle optionally having one or more substituents besides the oxo (provided that 2,3-dioxopyrrolidine ring is excluded); R1 represents hydrogen, an optionally substituted hydrocarbon group, or an optionally substituted heterocyclic group; and-------- indicates a single bond or a double bond. It has high antagonistic activity against a tachykinin receptor, especially an SP receptor.
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Page 67

(2010/02/08)

An efficient method for selective deprotection of trimethylsilyl ethers, tetrahydropyranyl ethers, ethylene acetals and ketals under solvent-free conditions
1-Benzyl-4-aza-1-azoniabicyclo[2.2.2]octane dichromate (BAABOD) is a useful reagent for the selective cleavage of trimethylsilyl ethers, tetrahydropyranyl ethers, ethylene acetals and ketals to their corresponding alcohols, aldehydes and ketones. This method is very simple and efficient and the reaction has been carried out under solvent-free conditions in the presence of anhydrous aluminium chloride.
Hajipour, Abdol R.,Mallakpour, Shadpour E.,Mohammadpoor-Baltork,Khoee
p. 1251 - 1256
(2007/10/03)

An efficient method for selective deprotection of trimethylsilyl ethers, tetrahydropyranyl ethers, ethylene acetals, and ketals under microwave irradiation
1-Benzyl-4-aza-1-azoniabicyclo [2.2.2] octane dichromate (BAABOD) is a useful reagent for the selective cleavage of trimethylsilyl ethers, tetrahydropyranyl ethers, ethylene acetals and ketals to their corresponding alcohols, aldehydes and ketones. This method is very simple and efficient and the reaction has been carried out under microwave irradiation.
Hajipour,Mallakpour,Mohammadpoor-Baltork,Khoee
p. 611 - 620
(2007/10/03)

Potassium dodecatangestocobaltate trihydrate (K5CoW12O40·3H2O): A mild and efficient catalyst for deprotection of dioxolanes and trimethylsilyl ethers
Mild and easy deprotection of benzylic dioxolanes to carbonyl compounds (in refluxing dry acetone) and trimethylsilyl ethers to alcohols in acetonitrile at ambient temperature has been carried out in excellent yields under K5CoW12O40·3H2O (0.01 molar equiv.) catalysis.
Habibi, Mohammad H,Tangestaninejad, Shahram,Mohammadpoor-Baltork, Iraj,Mirkhani, Valiollah,Yadollahi, Bahram
p. 6771 - 6774
(2007/10/03)

Butyltriphenylphosphonium tetrahydroborate (BTPPTB) as a selective reducing agent for reduction of organic compounds
Butyltriphenylphosphonium tetraborate (BTPPTB) (1) has been found to be a selective and versatile reducing agent. The reagent in dichloromethane solution or under solvent-free conditions is very useful for reduction of aldehydes, ketones, carboxylic acid chlorides, aryl azides, and aroyl azides to the corresponding alcohols, amines and amides, respectively.
Hajipour,Mallakpour
p. 1177 - 1185
(2007/10/03)

Potassium dodecatangestocobaltate trihydrate (K5CoW12O40·3H2O): A mild and efficient catalyst for the tetrahydropyranylation of alcohols and their detetrahydropyranylation
A simple, mild and effective method for tetrahydropyranylation of a variety of alcohols and cleavage of their tetrahydropyranyl ethers at ambient temperature in the presence of K5CoW12O40·3H2O as the catalyst with high turnovers is described.
Habibi, Mohammad H.,Tangestaninejad, Shahram,Mohammadpoor-Baltork, Iraj,Mirkhani, Valiollah,Yadollahi, Bahram
p. 2851 - 2853
(2007/10/03)

Benzyltriphenylphosphonium tetraborate (BTPPTB) as a selective reducing agent for reduction of aldehydes and ketones to the corresponding alcohols
Benzyltriphenylphosphonium tetraborate (BTPPTB) (1) generated as a white solid from benzyltriphenylphosphonium chloride and sodium borohydride has been found to be a selective and versatile reducing agent. The reagent in methanol is very useful for reduction of aldehydes and ketones to the corresponding alcohols.
Hajipour,Mallakpour,Najafi
p. 165 - 170
(2007/10/03)

Synthesis and antiparasitic and antitumor activity of 2,4-diamino-6- (arylmethyl)-5,6,7,8-tetrahydroquinazoline analogues of piritrexim
Nineteen previously undescribed 2,4-diamino-6-(arylmethyl)-5,6,7,8- tetrahydroquinazolines (5a-m, 10-12) were synthesized as part of a larger effort to assess the therapeutic potential of lipophilic dihydrofolate reductase (DHFR) inhibitors against opportunistic infections of AIDS. Condensation of appropriately substituted (arylmethyl)triphenylphosphoranes with 4,4-ethylenedioxycyclohexanone, followed by hydrogenation (H2/Pd-C) and acidolysis, yielded the corresponding 4-(arylmethyl)cyclohexanones, which were then condensed with cyanoguanidine to form the tetrahydroquinazolines. Three simple 2,4-diamino-6-alkyl-5,6,7,8-tetrahydroquinazoline model compounds (9a-c) were also prepared in one step from commercially available 4-alkylcyclohexanones by this method. Enzyme inhibition assays against rat liver DHFR, Pneumocystis carinii DHFR, and the bifunctional DHFR-TS enzyme from Toxoplasma gondii were carried out, and the selectivity ratios IC50(rat)/IC50(P. carinii) and IC50(rat)/IC50(T. gondii) were compared. The three most potent inhibitors of P. carinii DHFR were the 2,5- dimethoxybenzyl (5j), 3,4-dimethoxybenzyl (5k), and 3,4,5-trimethoxybenzyl (51) analogues, with IC50 values of 0.057, 0.10, and 0.091 μM, respectively. The remaining compounds generally had IC50 values in the 0.1- 1.0 μM range. However all the compounds were more potent against the rat liver enzyme than the P. carinii enzyme and thus were nonselective. The T. gondii enzyme was always more sensitive than the P. carinii enzyme, with most of the analogues giving IC50 values of 0.01-0.1 μM. Moderate 5-10-fold selectivity for T. gondii versus rat liver DHFR was observed with five compounds, the best combination of potency and selectivity being achieved with the 2-methoxybenzyl analogue 5d, which had an IC50 of 0.014 μM and a selectivity ratio of 8.6. One compound (51) was tested for antiproliferative activity against P. carinii trophozoites in culture at a concentration of 10 μg/mL and was found to completely suppress growth over 7 days. The suppressive effect of 51 was the same as that of trimethoprim (10 μg/mL) + sulfamethoxazole (250 μg/mL), a standard clinical combination for the treatment of P. carinii pneumonia in AIDS patients. Four compounds (5a,h,k,l) were tested against T. gondii tachyzoites in culture and were found to have a potency (IC50 = 0.1-0.5 μM) similar to that of pyrimethamine (IC50 = 0.69 μM), a standard clinical agent for the treatment of cerebral toxoplasmosis in AIDS patients. Compound 5h was also active against T. gondii infection in mice when given qdx8 by peritoneal injection at doses ranging from 62.5 (initial dose) to 25 mg/kg. Survival was prolonged to the same degree as with 25 mg/kg clindamycin, another widely used drug against toxoplasmosis. Three compounds (5j-l) were tested for antiproliferative activity against human tumor cells in culture. Among the 25 cell lines in the National Cancer Institute panel for which data were confirmed in two independent experiments, the IC50 for at least two of these compounds was 50 of 50 was 0.01 μM.
Rosowsky, Andre,Papoulis, Andrew T.,Forsch, Ronald A.,Queener, Sherry F.
p. 1007 - 1017
(2007/10/03)

Cobalt(II) chloride hexahydrate-zinc-dimethylformamide-water: An efficient system for reduction of aldehydes to alcohols
The system cobalt(II) chloride hexahydrate-zinc-dimethylformamide-water converts aldehydes to the corresponding alcohols at room temperature in excellent yields.
Baruah, Robindra N.
p. 182 - 183
(2007/10/02)

Efficient pyrimidine dimer radical anion splitting in low polarity solvents
Photosensitized pyrimidine dimer splitting by a covalently linked methoxybenzene exhibited a strong solvent dependence. Fluorescence of the chromophore was quenched by the attached dimer, which was indicative of electron transfer from excited chromophore to dimer. The quantum efficiency of splitting of the dimer radical anion in the linked dimer?--chromophore?+ was calculated from the observed quantum yields of splitting and the degree of fluorescence quenching. The quantum efficiency of dimer radical anion splitting was remarkably dependent on solvent polarity, ranging from 0.05 in water to ～0.5 in low polarity solvent mixtures (e.g., heptane/1,4-dioxane, 95:5). The results were rationalized in terms of competition of splitting and back electron transfer within the charge-separated species. The latter pathway may be slowed due to its exergonicity in low polarity media, in accord with Marcus inverted behavior. Photolyases may be effective for splitting dimers by providing catalytic groups and a medium in which both dimer radical anion formation and splitting are efficient.
Hartzfeld, Donna G.,Rose, Seth D.
p. 850 - 854
(2007/10/02)

An efficient reduction system - NiCl2·6H2O-Zn/DMF-H2O for conversion of aldehydes to alcohols
Aldehydes were efficiently converted to the corresponding alcohols at room temperature, with NiCl2·6H2O-Zn/DMF-H2O system.
Baruah, Robindra N.
p. 5417 - 5418
(2007/10/02)

Intramolecular rhodium carbenoid insertions into aromatic C-H bonds. Preparation of 1,3-dihydrothiophene 2,2-dioxides fused onto aromatic rings
The preparation of 1-carboalkoxy-1,3-dihydrobenzenothiophene 2,2-dioxides via rhodium acetate or rhodium trifluoro-acetate catalyzed decomposition of α-diazo-β-arylmethanesulfonyl esters is described.The reaction has been extended to yield 1,3-dihydrothiophene 2,2-dioxides fused to the 2,3 position of thiophene and indole, but not of furans.In the latter case products derived from the opening of the furan ring were obtained.Key words: synthesis, 1-carboalkoxy-1,3-dihydrobenzothiophene 2,2-dioxides, intramolecular carbenoid insertions, rhodium acetate catalysis.
Babu, Suresh D.,Hrytsak, Michael D.,Durst, Tony
p. 1071 - 1076
(2007/10/02)

DEOXYGENATION OF ALDEHYDES AND KETONES WITH SODIUM CYANOBOROHYDRIDE
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.
p. 1315 - 1324
(2007/10/02)