- Synthesis of Aryl Ketones by the Pd-Catalyzed C-H Activation of Arenes and Intermolecular Carbopalladation of Nitriles
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The palladium-catalyzed reaction of simple arenes and nitriles provides good to excellent yields of aryl ketones or the corresponding hindered imines. The addition of a small amount of DMSO increases the yields dramatically. Both intermolecular and intramolecular examples of this process are successful. This novel chemistry is believed to involve palladium-catalyzed C?H activation, followed by carbopalladation of the nitrile. Copyright
- Zhou, Chengxiang,Larock, Richard C.
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- Water-Tolerant ortho-Acylation of Phenols
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A metal-free, water-tolerant, and one-pot process for ortho-acylation of phenols promoted by the iodine source/hydrogen peroxide system has been developed. This transformation undergoes ether formation, iodocyclization, C-C bond cleavage, and oxidative hydrolysis in a one-step manner, which is supported by control experiments.
- Dong, Shuang-Feng,Gao, Zhi-Yuan,He, Yu,Liu, Xu,Loh, Teck-Peng,Tian, Jie-Sheng,Wu, Peng
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supporting information
p. 6594 - 6598
(2021/09/02)
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- Substituent and Surfactant Effects on the Photochemical Reaction of Some Aryl Benzoates in Micellar Green Environment?
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In this study, we carried out preparative and mechanistic studies on the photochemical reaction of a series of p-substituted phenyl benzoates in confined and sustainable micellar environment. The aim of this work is mainly focused to show whether the nature of the surfactant (ionic or nonionic) leads to noticeable selectivity in the photoproduct formation and whether the electronic effects of the substituents affect the chemical yields and the rate of formation of the 5-substituted-2-hydroxybenzophenone derivatives. Application of the Hammett linear free energy relationship (LFER) on the rate of formation of benzophenone derivatives, on the lower energy band of the UV-visible absorption spectra of the aryl benzoates and 5-substituted-2-hydroxybenzophenone derivatives allows a satisfactory quantification of the substituent effects. Furthermore, UV-visible and 2D-NMR (NOESY) spectroscopies have been employed to measure the binding constant Kb and the location of the aryl benzoates within the hydrophobic core of the micelle. Finally, TD-DFT calculations have been carried out to estimate the energies of the absorption bands of p-substituted phenyl benzoates and 5-substituted-2-hydroxybenzophenone derivatives providing good linear correlation with those values measured experimentally.
- Siano, Gastón,Crespi, Stefano,Bonesi, Sergio M.
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p. 1298 - 1309
(2021/05/07)
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- Photo-Fries rearrangement in flow under aqueous micellar conditions
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A flow edition of photo-Fries rearrangement for the synthesis of 2-acylphenols in an aqueous micellar medium has been described. We take advantage of a narrow channel reactor and micelle-induced confinement effect to refine both the efficiency and selectivity of the parent photoreaction. This journal is
- Chen, Chun-Jen,Chien, Chia-Chen,Kao, Shih-Chieh,Wu, Yen-Ku
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p. 15470 - 15472
(2020/12/25)
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- Nickel-Catalyzed Decarbonyloxidation of 3-Aryl Benzofuran-2(3H)-ones to 2-Hydroxybenzophenones
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We have developed a protocol to facilitate the nickel-catalyzed decarbonyloxidation of 3-aryl benzofuran-2(3H)-ones to 2-hydroxybenzophenones under mild conditions, which is an efficient approach for the decarbonyloxidation of lactones in organic synthesis. A diverse range of substrates can undergo C(O)-O/C(O)-C bond cleavage to generate the target products in good yields. These 2-hydroxybenzophenones can be converted into a variety of compounds via reactions such as esterification, cyclization, and reduction.
- Tong, Zhou,Tang, Zhi,Au, Chak-Tong,Qiu, Renhua
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p. 8533 - 8543
(2020/07/16)
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- Selectivity in the photo-fries rearrangement of some aryl benzoates in green and sustainable media. Preparative and mechanistic studies
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Irradiation of a series of p-substituted aryl benzoates under N2 atmosphere in homogeneous and micellar media was investigated by means of steady-state condition and of time-resolved spectroscopy. A notable selectivity in favor of the 2-hydroxybenzophenone derivatives was observed in micellar media. The benzophenone derivatives were the main photoproduct. On the other hand, in homogeneous media (cyclohexane, acetonitrile, and methanol) the observed product distribution was entirely different, viz. substituted 2-hydroxybenzophenones, p-substituted phenols, benzyl and benzoic acid were found. The binding constants in the surfactant were also measured and NOESY experiments showed that the aryl benzoates were located in the hydrophobic core of the micelle. Laser flash photolysis experiments led to the characterization of both p-substituted phenoxy radical and substituted 2-benzoylcyclohexadienone transients in homogeneous and micellar environment.
- Siano, Gastón,Bonesi, Sergio M.,Crespi, Stefano,Mella, Mariella
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p. 4338 - 4352
(2019/05/01)
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- Expanded campestarene hosts for tetra- and dinuclear uranyl(VI) complexes
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The first expanded campestarenes based on a keto-enamine scaffold have been constructed using uranyl acetate as a template. Macrocycles with six and eight aryl rings in their backbone host dinuclear and tetranuclear uranium(vi) species, respectively. The complexes were characterized by SCXRD, FT-IR, UV-vis, and NMR spectroscopy, and DFT calculations corroborated their structures.
- Chaudhry, Mohammad T.,Lelj, Francesco,MacLachlan, Mark J.
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supporting information
p. 11869 - 11872
(2018/12/01)
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- One-pot synthesis of ortho-acylphenols by palladium-catalyzed phenol C–H addition to nitriles
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The regioselective one-pot synthesis of ortho-acylphenols via the palladium-catalyzed addition of phenols to nitriles and subsequent hydrolysis is reported. The acylation reaction proceeded smoothly using the Pd(OAc)2/DMSO system and TFA as the additive. This method also provides a direct strategy for the synthesis of a salicylketoxime scaffold.
- Jiang, Tao-Shan,Gan, Bei,Wang, Xi,Zhang, Xiuli
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supporting information
p. 4197 - 4199
(2017/10/06)
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- Metal-free oxidative fluorination of phenols with [18F]fluoride
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The radiochemical synthesis of [18F]4-fluorophenols is based on phenol umpolung under oxidative conditions and direct nucleophilic fluorination with [18F]fluoride (see scheme, TBAF=tetra-n-butylammonium fluoride, TFA=trifluoroacetic acid). Readily available O-unprotected 4-tert-butyl phenols are used as precursors in this one-pot protocol. The reaction is completed in less than 30 minutes at room temperature and can be performed using standard or microfluidic technology. Copyright
- Gao, Zhanghua,Lim, Yee Hwee,Tredwell, Matthew,Li, Lei,Verhoog, Stefan,Hopkinson, Matthew,Kaluza, Wojciech,Collier, Thomas Lee,Passchier, Jan,Huiban, Mickael,Gouverneur, Véronique
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supporting information; experimental part
p. 6733 - 6737
(2012/08/28)
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- One-pot synthesis of 3,4-disubstituted coumarins under catalysis of Mn 3O4 nanoparticles
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The one-pot synthesis of 3,4-disubstituted coumarins from substituted 2-(hydroxymethyl)phenols with β-keto esters catalyzed by Mn 3O4 nanoparticles was developed. A series of 3,4-disubstituted coumarin derivatives were obtained in good yields. A new method for the one-pot synthesis of 3,4-disubstituted coumarins from substituted 2-(hydroxymethyl)phenols with β-keto esters catalyzed by Mn 3O4 nanoparticles has been developed. A series of 3,4-disubstituted coumarin derivatives were synthesized from substituted 2-(hydroxymethyl)phenols and β-keto esters in good yields. Copyright
- Sun, Huayin,Zhang, Yonghui,Guo, Fengfeng,Yan, Yizhe,Wan, Changfeng,Zha, Zhenggen,Wang, Zhiyong
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p. 480 - 483
(2012/03/09)
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- Synthesis of aryl ketones or ketimines by palladium-catalyzed arene C-H addition to nitriles
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The unprecedented palladium-catalyzed C-H addition of arenes to nitriles provides moderate to excellent yields of aryl ketones or the corresponding hindered imines. The addition of a small amount of DMSO increases the yields dramatically. Both intermolecular and intramolecular reactions are successful, although the intramolecular reactions tend to be more sluggish. This novel chemistry is believed to involve palladium-catalyzed C-H activation of the arene by electrophilic aromatic substitution, followed by the unusual carbopalladation of a nitrile. Similar reactions have been successfully developed employing arylboronic acids and nitriles. A concise route to xanthones starting from cheap starting materials has been developed employing this synthetic protocol.
- Zhou, Chengxiang,Larock, Richard C.
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p. 3551 - 3558
(2007/10/03)
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- 2-Acyl-6-aminomethylphenol derivatives
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A 2-acyl-6-aminomethylphenol derivative having the formula (I): STR1 wherein R1 represents a straight chain or branched chain alkyl group of 1 to 6 carbon atoms unsubstituted or substituted with 1 to 3 halogen atoms; a hydrogen atom or a group having the formula (II): wherein n represents 0 or an integer of 1 to 6; R7 represents a cycloalkyl group of 3 to 8 carbon atoms unsubstituted or substituted with at least one lower alkyl group; a phenyl group unsubstituted or substituted with at least one lower alkyl group, a halogen atom, a lower alkoxy group or a lower alkylthio group; a lower alkoxy group; a lower alkylthio group; a lower alkylsulfinyl group; a lower alkylsulfonyl group; an N-lower alkylamino group; an N,N-di-lower alkylamino group; or a pyridyl, furyl or thienyl group; R2 represents a straight chain or branched chain alkyl group of 1 to 6 carbon atoms; a cycloalkyl group of 4 to 8 carbon atoms unsubstituted or substituted with at least one lower alkyl group; a phenyl group unsubstituted or substituted with at least one lower alkyl group, a lower alkoxy group, a lower alkylthio group or a halogen atom; or a lower alkylthio group; R3 and R4 each represents a hydrogen atom or R2 and R3 or R2 and R4 when taken together represent an alkylene group of 2 to 5 carbon atoms unsubstituted or substituted with 1 or 2 lower alkyl groups; R5 represents a hydrogen atom or a lower alkyl group; and R6 represents a hydrogen atom, a lower alkyl group or an acyl group, and the pharmaceutically acceptable acid addition salt thereof having anti-inflammatory, analgesic, antipyretic, diuretic and hypotensive effects that can be used for preventing and curing diseases caused by inflammation, edema, hypertension, etc. are disclosed. Also disclosed is a process for preparing such derivative or a pharmaceutically acceptable acid addition salt thereof.
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