- Selective Oxidation of Alkylarenes to the Aromatic Ketones or Benzaldehydes with Water
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Here a palladium-catalyzed oxidation method for converting alkylarenes into the aromatic ketones or benzaldehydes with water as the only oxygen donor is reported. This C-H bond oxidation functionalization does not require other oxidants and hydrogen accep
- Du, Jihong,Duan, Baogen,Liu, Kun,Liu, Renhua,Yu, Feifei,Yuan, Yongkun,Zhang, Chenyang,Zhang, Jin
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supporting information
(2022/02/09)
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- Iron-catalyzed arene C-H hydroxylation
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The sustainable, undirected, and selective catalytic hydroxylation of arenes remains an ongoing research challenge because of the relative inertness of aryl carbon-hydrogen bonds, the higher reactivity of the phenolic products leading to over-oxidized by-products, and the frequently insufficient regioselectivity. We report that iron coordinated by a bioinspired L-cystine-derived ligand can catalyze undirected arene carbon-hydrogen hydroxylation with hydrogen peroxide as the terminal oxidant. The reaction is distinguished by its broad substrate scope, excellent selectivity, and good yields, and it showcases compatibility with oxidation-sensitive functional groups, such as alcohols, polyphenols, aldehydes, and even a boronic acid. This method is well suited for the synthesis of polyphenols through multiple carbon-hydrogen hydroxylations, as well as the late-stage functionalization of natural products and drug molecules.
- Cheng, Lu,Wang, Huihui,Cai, Hengrui,Zhang, Jie,Gong, Xu,Han, Wei
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- Enantioselective synthesis of 3-substituted dihydrobenzofurans through iridium-catalyzed intramolecular hydroarylation
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Intramolecular hydroarylationviaC-H activation is one of the most powerful methods to synthesize carbo- and heterocyclic compounds, whereas we still have room for developing a highly enantioselective variant of the reaction. Here we describe Ir-catalyzed enantioselective intramolecular hydroarylation ofm-allyloxyphenyl ketones. The enantioselective cyclization was efficiently catalyzed by a cationic iridium complex coordinated with a conventional chiral bisphosphine ligand to give benzofurans in high yields with high enantioselectivity. A carbonyl group of ketones functioned as an effective directing group for the C-H activation. In terms of synthetic utility, we also achieved one-pot synthesis of chiral 3-substituted dihydrobenzofurans from readily available allylic carbonates andm-hydroxyacetophenonesviasequential Pd-catalyzed allylic substitution and Ir-catalyzed intramolecular hydroarylation.
- Nishimura, Takahiro,Sakamoto, Kana
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supporting information
p. 684 - 690
(2021/02/06)
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- Electrophotocatalytic C?H Heterofunctionalization of Arenes
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The electrophotocatalytic heterofunctionalization of arenes is described. Using 2,3-dichloro-5,6-dicyanoquinone (DDQ) under a mild electrochemical potential with visible-light irradiation, arenes undergo oxidant-free hydroxylation, alkoxylation, and amination with high chemoselectivity. In addition to batch reactions, an electrophotocatalytic recirculating flow process is demonstrated, enabling the conversion of benzene to phenol on a gram scale.
- Huang, He,Lambert, Tristan H.
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supporting information
p. 11163 - 11167
(2021/04/19)
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- Arylation of Aldehydes to Directly Form Ketones via Tandem Nickel Catalysis
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A nickel-catalyzed arylation of both aliphatic and aromatic aldehydes proceeds with air-stable (hetero)arylboronic acids, with an exceptionally wide substrate scope. The neutral condition tolerates acidic hydrogen and sensitive polar groups and also preserves α-stereocenters of some chiral aldehydes. Interestingly, this nickel(0) catalysis does not follow common 1,2-insertion of arylmetal species to aldehydes and β-hydrogen elimination.
- Lei, Chuanhu,Zhu, Daoyong,Tangcueco, Vicente Iii Tiu,Zhou, Jianrong Steve
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supporting information
p. 5817 - 5822
(2019/08/26)
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- A Nickel-Catalyzed Carbonyl-Heck Reaction
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The use of transition-metal catalysis to enable the coupling of readily available organic molecules has greatly enhanced the ability of chemists to access complex chemical structures. In this work, an intermolecular coupling reaction that unites organotriflates and aldehydes is presented. A unique catalyst system is identified to enable this reaction, featuring a Ni0 precatalyst, a tridentate Triphos ligand, and a bulky amine base. This transformation provides access to a variety of ketone-containing products without the selectivity- and reactivity-related challenges associated with more traditional Friedel–Crafts reactions. A Heck-type mechanism is postulated, wherein the π bond of the aldehyde takes the role of the olefin in the insertion/elimination steps.
- Vandavasi, Jaya Kishore,Hua, XiYe,Halima, Hamdi Ben,Newman, Stephen G.
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p. 15441 - 15445
(2017/11/10)
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- Photocatalytic Hydrogen-Evolution Cross-Couplings: Benzene C-H Amination and Hydroxylation
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We present a blueprint for aromatic C-H functionalization via a combination of photocatalysis and cobalt catalysis and describe the utility of this strategy for benzene amination and hydroxylation. Without any sacrificial oxidant, we could use the dual catalyst system to produce aniline directly from benzene and ammonia, and phenol from benzene and water, both with evolution of hydrogen gas under unusually mild conditions in excellent yields and selectivities.
- Zheng, Yi-Wen,Chen, Bin,Ye, Pan,Feng, Ke,Wang, Wenguang,Meng, Qing-Yuan,Wu, Li-Zhu,Tung, Chen-Ho
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supporting information
p. 10080 - 10083
(2016/09/04)
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- Design and synthesis of cyclic acylguanidines as BACE1 inhibitors
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Based on the lead compound 1 reported in literature, a series of novel BACE1 inhibitors were designed and synthesized, among which compound 11 exhibited a 14-fold improvement in potency over the lead compound 1. This represents a good lead for the discovery of more promising BACE1 inhibitors for the potential treatment of AD.
- Liu, Jia-Kuo,Gu, Wei,Cheng, Xiao-Rui,Cheng, Jun-Ping,Zhou, Wen-Xia,Nie, Ai-Hua
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supporting information
p. 1327 - 1330
(2015/12/31)
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- BENZHYDRYL DERIVATIVES FOR THE TREATMENT OF RESPIRATORY DISEASES
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The invention relates to novel compounds of formula (I) having a benzhydryl structure which are both phosphodiesterase 4 (PDE4) enzyme inhibitors and muscarinic M3 receptor antagonists, methods of preparing such compounds, compositions containing them and therapeutic use thereof.
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Page/Page column 45
(2015/06/18)
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- BENZHYDRYL DERIVATIVES
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Compounds having a benzhydryl structure represented by formula (I) described herein are both phosphodiesterase 4 (PDE4) enzyme inhibitors and muscarinic M3 receptor antagonists and are useful for treating diseases of the respiratory tract.
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Paragraph 0266; 0267; 0268
(2015/06/17)
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- Synthesis of structurally diverse diarylketones through the diarylmethyl sp3 C-H oxidation
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Under open-flask conditions, an efficient method to assemble a series of diversely functionalized diarylketones in the presence of commercially available NBS has been developed. Yields of up to 99% have been achieved employing diarylmethanes as starting material. Based on 18O-labeled experiment, the addition of stoichiometric water eventually leads to excellent yields in all carbonylation cases.
- He, Chao,Zhang, Xiaohui,Huang, Ruofeng,Pan, Jing,Li, Jiaqiang,Ling, Xuege,Xiong, Yan,Zhu, Xiangming
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p. 4458 - 4462
(2014/08/05)
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- COMPOUNDS HAVING MUSCARINIC RECEPTOR ANTAGONIST AND BETA2 ADRENERGIC RECEPTOR AGONIST ACTIVITY
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Compounds of formula (I) defined herein act both as muscarinic receptor antagonists and beta2 adrenergic receptor agonists and are useful for the prevention and/or treatment of broncho-obstructive or inflammatory diseases.
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Paragraph 0469-0471
(2014/06/24)
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- COMPOUNDS HAVING MUSCARINIC RECEPTOR ANTAGONIST AND BETA2 ADRENERGIC RECEPTOR AGONIST ACTIVITY
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The present invention relates to compounds acting both as muscarinic receptor antagonists and beta2 adrenergic receptor agonists, to processes for their preparation, to compositions comprising them, to therapeutic uses and combinations with other pharmaceutical active ingredients.
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Page/Page column 113; 114; 115
(2014/06/24)
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- COMPOUNDS HAVING MUSCARINIC RECEPTOR ANTAGONIST AND BETA2 ADRENERGIC RECEPTOR AGONIST ACTIVITY
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Compounds of formula (I) described herein act both as muscarinic receptor antagonists and beta2 adrenergic receptor agonists and are useful for the prevention and/or treatment of broncho-obstructive or inflammatory diseases.
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Page/Page column
(2014/06/24)
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- Simultaneous identification of Fenton degradation by-products of diclofenac, ibuprofen and ketoprofen in aquatic media by comprehensive two-dimensional gas chromatography coupled with mass spectrometry
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Diclofenac, ibuprofen and ketoprofen are anti-inflammatory drugs intensively used both in human and animal treatment. Due to their high stability these compounds are partially removed by wastewater treatment plants and from this reason the development of some alternative treatments such as advanced oxidative processes are necessary. The main problems in the optimization of an advanced oxidative process rise from the difficulties which appear in the identification of degradation by-products necessary for the establishment of degradation pathway. In this paper a developed method for the simultaneous identification of Fenton degradation by-products of the three above mentioned pharmaceuticals is presented. The obtained results show the comprehensive two-dimensional gas chromatography coupled with mass spectrometry as a proper method for the analysis of the complex mixture of compounds resulted from the Fenton degradation process. Moreover, some compounds never mentioned in the scientific literature were identified. (Chemical Equation Presented).
- Beldean-Galea, Mihail Simion,Coman, Virginia,Copaciu, Florina,Thiébaut, Didier,Vial, Jér?me
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p. 1021 - 1027
(2015/07/15)
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- D-Glucose as green ligand for selective copper-catalyzed phenol synthesis from aryl halides with an easy catalyst removal
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With the growing demand of environmentally friendly reagents for organic reactions, for the first time the utility of d-glucose as a ligand in its direct form has been described using a typical example of copper-catalyzed coupling reaction for phenol synthesis with a high degree of selectivity and easy catalyst removal.
- Thakur, Krishna Gopal,Sekar, Govindasamy
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supporting information; experimental part
p. 6692 - 6694
(2011/07/09)
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- Hydroxylation of benzophenone with ammonium phosphomolybdate in the solid state via UV photoactivation
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UV photoactivation of a mixture of benzophenone and ammonium phosphomolybdate (APM) in the solid state splits adsorbed moisture, resulting in selectively hydroxylated benzophenone and leaving an electron trapped in green (reduced) solid APM. The Royal Soc
- Basu, Mrinmoyee,Sarkar, Suresh,Pande, Surojit,Jana, Subhra,Kumar Sinha, Arun,Sarkar, Sougata,Pradhan, Mukul,Pal, Anjali,Pal, Tarasankar
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body text
p. 7191 - 7193
(2010/03/25)
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- Direct access to ketones from aldehydes via rhodium-catalyzed cross-coupling reaction with potassium trifluoro(organo)borates
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A direct cross-coupling reaction of aromatic aldehydes with potassium trifluoro(organo)borates afforded ketones in high yields and under mild conditions in the presence of a rhodium catalyst and acetone. This new reaction, involving a formal aldehyde C-H bond activation, is believed to proceed via a Heck-type mechanism followed by hydride transfer to acetone. Copyright
- Pucheault, Mathieu,Darses, Sylvain,Genet, Jean-Pierre
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p. 15356 - 15357
(2007/10/03)
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- Palladium-catalyzed synthesis of aryl ketones from boronic acids and carboxylic acids activated in situ by pivalic anhydride
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A new palladium-catalyzed cross-coupling reaction between arylboronic acids and mixed anhydrides, generated in situ from carboxylic acids and pivalic anhydride, is presented. Optimization of the new catalyst and the reaction conditions led to the development of a convenient one-pot ketone synthesis directly from carboxylic and boronic acids in the presence of different (phosphane)palladium complexes in wet THF at 60 °C. Systematic studies were performed to elucidate the reaction mechanism of this transformation. The scope and the limitations of the new process are demonstrated by the synthesis of 33 functionalized ketones. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
- Goossen, Lukas J.,Ghosh, Keya
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p. 3254 - 3267
(2007/10/03)
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A new method for the meta acylation of anisole and its para-methyl or fluoro derivatives, is described. Addition of two trimethysilyl groups in the 2 and 5 positions (relative to the methoxy group), followed by hydrolysis affords the corresponding 5-trimethylsilyl-3-cyclohexenones. Electrophilic substitution of the silyl group using RCOC1/2AlCl3 at low temperature provides, after final aromatisation promoted by Pd/C or CuBr2/LiBr, the expected meta acylated products. This mode of meta functionalization has been successfully applied to an original synthesis of ketoprofen starting from anisole.
- Bennetau,Rajarison,Dunogues
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p. 1179 - 1188
(2007/10/02)
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- Preparation and trapping of 3-lithium-O-lithiophenoxide
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3-Bromophenol and 3-bromothiophenol are converted into the title compounds by proton abstraction followed by halogen-metal exchange with tert-butyllithium. The resulting dianions are then trapped on carbon with various electrophiles.
- Selnick,Bourgeois,Butcher,Radzilowski
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p. 2043 - 2046
(2007/10/02)
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- Thermal and Photochemical Reactions of Triarylmethyl Peroxides
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The thermal and photochemical decomposition products of p-benzoyltriphenylmethyl peroxide (I), of m-benzoyltriphenylmethyl peroxide (II), and of isotopically labeled analogues indicate rapid radical 1,2-migrations precluding other radical processes such as β-elimination from the incipient radical.The mechanism of these processes is interpreted in terms of these rearrangements as well as reversible elimination of O2 from the starting peroxide.Differences in the two isomeric peroxides are assessed.
- Neckers, D.C.,Linden, Shwn-Meei,Williams, B. Lee,Zakrzewski, Andrzej
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p. 131 - 135
(2007/10/02)
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- Analgesic 2-(M-benzoylphenoxy)-propionic acid derivatives
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Method of providing an analgesic effect by administring compounds having the general formula I STR1 in which each of R1 and R4 is independently hydrogen or a C1-4 alkyl, and each of R2 and R3 is independently hydrogen, fluorine, chlorine, bromine or a C1-4 alkyl or their pharmaceutically acceptable salts. The invention provides also compounds of fromula (I) where each of R1, R2 and R3 is independently hydrogen or C1-4 alkyl.
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- Benzophenones and benzhydrols
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Compounds having the formula STR1 WHERE X is --CO-- or --CHOH--, Y and Z are halogen, alkyl, trifluoromethyl, alkoxy, hydroxy, nitro, cyano, carboxy, carbalkoxy, carbamoyl, or alkylthio, and m and n are 0, 1, or 2 Are useful in controlling undesirable secondary growth in plants, particularly sucker growth in tobacco.
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