- Very long chain alkylresorcinols accumulate in the intracuticular wax of rye (Secale cereale L.) leaves near the tissue surface
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Alkylresorcinols (ARs) are bioactive compounds occurring in many members of the Poaceae, likely at or near the surface of various organs. Here, we investigated AR localization within the cuticular wax layers of rye (Secale cereale) leaves. The total wax m
- Ji, Xiufeng,Jetter, Reinhard
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- Palladium-Catalyzed Reductive Carbonylation of (Hetero) Aryl Halides and Triflates Using Cobalt Carbonyl as CO Source
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An efficient protocol for the reductive carbonylation of (hetero) aryl halides and triflates under CO gas-free conditions using Pd/Co2(CO)8 and triethylsilane has been developed. The mild reaction conditions, enhanced chemoselectivity and, easy access to heterocyclic and vinyl carboxaldehydes highlights its importance in organic synthesis.
- Dogga, Bhushanarao,Joseph, Jayan T.,Kumar, C. S. Ananda
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supporting information
p. 309 - 313
(2020/12/23)
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- Synthesis method of 3, 5-dihydroxypentene benzene
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The invention provides a synthesis method of 3, 5-dihydroxypentene benzene. The synthesis method comprises the following steps: reacting 3, 5-dimethoxyphenol used as a raw material with a sulfonate halide reagent to generate sulfonate, carrying out cross-coupling reaction with a nucleophilic reagent to introduce amyl, and finally reducing methoxyl into phenolic hydroxyl, thereby obtaining the product 3, 5-dihydroxypentene benzene. The synthesis method solves the defects of high cost, complex route, low yield, poor purity and the like of the traditional process.
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Paragraph 0039-0041
(2020/07/21)
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- One-Pot Generation of Benzynes from Phenols: Formation of Primary Anilines by the Deoxyamination of Phenols
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Benzynes were selectively generated in situ from phenols and trapped regioselectively with potassium hexamethyldisilazide to form primary anilines following acidic workup. The direct conversion of a phenolic hydroxyl group into a free amino group is a useful method for the preparation of primary aryl amines that are hard to synthesize by using coupling reactions involving phenol derivatives with ammonia. Whereas reactions of ortho- and meta-substituted phenols produced meta-substituted anilines exclusively, those of para-substituted phenols provided ortho-silylanilines.
- Akai, Shuji,Ikawa, Takashi,Masuda, Shigeaki
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- Transition-Metal-Free C-C, C-O, and C-N Cross-Couplings Enabled by Light
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Transition-metal-catalyzed cross-couplings to construct C-C, C-O, and C-N bonds have revolutionized chemical science. Despite great achievements, these metal catalysts also raise certain issues including their high cost, requirement of specialized ligands, sensitivity to air and moisture, and so-called "transition-metal-residue issue". Complementary strategy, which does not rely on the well-established oxidative addition, transmetalation, and reductive elimination mechanistic paradigm, would potentially eliminate all of these metal-related issues. Herein, we show that aryl triflates can be coupled with potassium aryl trifluoroborates, aliphatic alcohols, and nitriles without the assistance of metal catalysts empowered by photoenergy. Control experiments reveal that among all common aryl electrophiles only aryl triflates are competent in these couplings whereas aryl iodides and bromides cannot serve as the coupling partners. DFT calculation reveals that once converted to the aryl radical cation, aryl triflate would be more favorable to ipso substitution. Fluorescence spectroscopy and cyclic voltammetry investigations suggest that the interaction between excited acetone and aryl triflate is essential to these couplings. The results in this report are anticipated to provide new opportunities to perform cross-couplings.
- Liu, Wenbo,Li, Jianbin,Querard, Pierre,Li, Chao-Jun
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supporting information
p. 6755 - 6764
(2019/05/06)
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- Solvent-free ruthenium-catalysed triflate coupling as a convenient method for selective azole-o-C-H monoarylation
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Metal-catalysed ortho-directed C-H functionalization usually faces selectivity issues in the competition between mono- and disubstitution processes. We report herein the ruthenium-catalysed N-directed C-H monoarylation of arylpyrazoles with a selectivity
- Abidi, Oumaima,Boubaker, Taoufik,Hierso, Jean-Cyrille,Roger, Julien
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supporting information
p. 5916 - 5919
(2019/06/24)
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- Synthesis and structure-activity relationship studies of O-biphenyl-3-yl carbamates as peripherally restricted fatty acid amide hydrolase inhibitors
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The peripherally restricted fatty acid amide hydrolase (FAAH) inhibitor URB937 (3, cyclohexylcarbamic acid 3′-carbamoyl-6-hydroxybiphenyl-3-yl ester) is extruded from the brain and spinal cord by the Abcg2 efflux transporter. Despite its inability to enter the central nervous system (CNS), 3 exerts profound antinociceptive effects in mice and rats, which result from the inhibition of FAAH in peripheral tissues and the consequent enhancement of anandamide signaling at CB1 cannabinoid receptors localized on sensory nerve endings. In the present study, we examined the structure-activity relationships (SAR) for the biphenyl region of compound 3, focusing on the carbamoyl and hydroxyl groups in the distal and proximal phenyl rings. Our SAR studies generated a new series of peripherally restricted FAAH inhibitors and identified compound 35 (cyclohexylcarbamic acid 3′-carbamoyl-5- hydroxybiphenyl-3-yl ester) as the most potent brain-impermeant FAAH inhibitor disclosed to date.
- Moreno-Sanz, Guillermo,Duranti, Andrea,Melzig, Laurin,Fiorelli, Claudio,Ruda, Gian Filippo,Colombano, Giampiero,Mestichelli, Paola,Sanchini, Silvano,Tontini, Andrea,Mor, Marco,Bandiera, Tiziano,Scarpelli, Rita,Tarzia, Giorgio,Piomelli, Daniele
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p. 5917 - 5930
(2013/08/23)
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- Total synthesis of moniliformediquinone and calanquinone A as potent inhibitors for breast cancer
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The first synthesis of moniliformediquinone has been achieved in which the longest linear sequence is only nine steps. The synthesis proceeds in 23% overall yield from commercially available 2,4,5-trimethoxybenzaldehyde. The key transformations include a
- Thangaraj, Shankar,Tsao, Wen-Shing,Luo, Yi-Wei,Lee, Yean-Jang,Chang, Chia-Fu,Lin, Chun-Cheng,Uang, Biing-Jiun,Yu, Chia-Chun,Guh, Jih-Hwa,Teng, Che-Ming
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experimental part
p. 6166 - 6172
(2011/09/19)
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- Aryl triflates: Useful coupling partners for the direct arylation of heteroaryl derivatives via Pd-catalyzed C-H activation-functionalization
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Aryl triflates were found to be suitable partners for the palladium catalyzed direct arylation of heteroaromatics via C-H activation- functionalization. The reaction conditions and the catalyst have a determining influence on the yields. The system combining PPh3 and Pd(OAc) 2 using KOAc as base and DMF as solvent promotes the selective 2- or 5-arylations in moderate to high yields. Several heteroaromatics such as furan, thiophene, thiazole or oxazole derivatives have been employed successfully. The electronic properties of the aryl triflates also have a decisive influence on the yields of the coupling products. Electron-rich aryl triflates gave satisfactory results, whereas the electron-poor ones led to the formation of phenols. The Royal Society of Chemistry 2008.
- Roger, Julien,Doucet, Henri
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p. 169 - 174
(2008/09/20)
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- Development of agonists, partial agonists and antagonists in the Δ8- tetrahydrocannabinol series
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Synthetic sequences were developed (Schemes 1 to 6) for the syntheses of various Δ8-THC analogs with either a rigid acetylenic linkage or a cis- double bond in different positions in the side chain. Various alkyne and cis- ene-Δ8-THC
- Crocker,Saha,Ryan,Wiley,Martin,Ross,Pertwee,Razdan
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p. 13907 - 13926
(2007/10/03)
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- An efficient synthesis of dihydroxyfluorenones via in situ Pd(0)-catalyzed cross-coupling
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All six dimethoxyfluorenones 6a-f and dihydroxyfluorenones 7a-f, wherein substitution occurs at only one aromatic ring, were conveniently prepared by palladium(0)-catalyzed cross-coupling reactions of aryl bromides/triflates 2a-e with in situ generated ar
- Ciske, Fred L.,Jones Jr., Winton D.
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p. 1195 - 1198
(2007/10/03)
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- Shortcut syntheses of naturally occurring 5-alkylresorcinols with DNA-cleaving properties
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Resorcinols such as 1-5 bearing long alkyl- or alkenyl substituents at the C-5 position, including bola-formed bis-resorcinol derivatives, have recently been isolated from natural sources and were shown to exhibit exceptional DNA-cleaving properties under oxidative conditions. Previous synthetic approaches to such compounds seem inappropriately lengthy with regard to their structural simplicity. Disclosed is a very flexible synthesis which assembles these targets from triflate 7 and well accessible alkenes, dienes, enynes, or dienynes, respectively, by means of a boron-mediated reaction manifold. As a typical example, hexadeca-1,15-dien-8-yne 11 is hydroborated with 9-H-9-BBN at all possible sites, the alkenyl borane entity of the resulting tris-borane 12 is selectively cleaved off to afford the desired (Z)-alkene group in a stereoselective manner, the remaining two terminal alkylboranes are treated with NaOMe, and the bis-borate complex 13 thus formed is finally used as the nucleophile for a palladium-catalyzed Suzuki cross-coupling reaction with triflate 7. This sequence is carried out in one pot and provides product 14 in 62% overall yield. Demethylation of 14 (and analogues) can be conveniently achieved by means of 9-iodo-9-BBN to afford the natural product 5. The efficiency and flexibility of this unprecedented approach which combines different features of classical and modern boron chemistry is further demonstrated by the synthesis of anacardic and ginkgolic acid derivatives.
- Fuerstner,Seidel
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p. 2332 - 2336
(2007/10/03)
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