- Hypervalent Iodine(III)-Promoted Radical Oxidative C-H Annulation of Arylamines with α-Keto Acids
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A novel catalyst-free radical oxidative C-H annulation reaction of arylamines with α-keto acids toward benzoxazin-2-ones synthesis under mild conditions was developed. This hypervalent iodine(III)-promoted process eliminated the use of a metal catalyst or additive with high levels of functional group tolerance. Hypervalent iodine(III) was both an oxidant and a radical initiator for this reaction. The synthetic utility of this method was confirmed by the synthesis of the natural product cephalandole A.
- Long, Lipeng,Wang, Jieyan,Gu, Liuqing,Yang, Shiguang,Qiao, Liang,Luo, Guotian,Chen, Zhengwang
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supporting information
p. 12084 - 12092
(2021/08/24)
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- Sex hormone releasing hormone receptor antagonists and uses thereof
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Gonadotropin-releasing hormone receptor antagonists and uses thereofThe invention relates to the field of organic chemistry, in particular to a compound or a pharmaceutically acceptable salt thereof. Isomer, prodrug, polymorph or solvate as well as prepar
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Paragraph 0053-0056
(2021/10/27)
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- Direct 1,2-Dicarbonylation of Alkenes towards 1,4-Diketones via Photocatalysis
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1,4-Dicarbonyl compounds are intriguing motifs and versatile precursors in numerous pharmaceutical molecules and bioactive natural compounds. Direct incorporation of two carbonyl groups into a double bond at both ends is straightforward, but also challenging. Represented herein is the first example of 1,2-dicarbonylation of alkenes by photocatalysis. Key to success is that N(n-Bu)4+ not only associates with the alkyl anion to avoid protonation, but also activates the α-keto acid to undergo electrophilic addition. The α-keto acid is employed both for acyl generation and electrophilic addition. By tuning the reductive and electrophilic ability of the acyl precursor, unsymmetric 1,4-dicarbonylation is achieved for the first time. This metal-free, redox-neutral and regioselective 1,2-dicarbonylation of alkenes is executed by a photocatalyst for versatile substrates under extremely mild conditions and shows great potential in biomolecular and drug molecular derivatization.
- Chen, Bin,Cheng, Yuan-Yuan,Hou, Hong-Yu,Lei, Tao,Tung, Chen-Ho,Wu, Li-Zhu,Yu, Ji-Xin
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supporting information
p. 26822 - 26828
(2021/11/17)
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- Diazotrifluoroethyl Radical: A CF3-Containing Building Block in [3 + 2] Cycloaddition
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We present herein a visible-light-induced [3 + 2] cycloaddition of a hypervalent iodine(III) reagent with α-ketoacids for the construction of 5-CF3-1,3,4-oxadiazoles that are of importance in medicinal chemistry. The reaction proceeds smoothly without a photocatalyst, metal, or additive under mild conditions. Different from the well-established trifluorodiazoethane (CF3CHN2), the diazotrifluoroethyl radical [CF3C(·)N2], a trifluoroethylcarbyne (CF3C?:) equivalent and an unusual CF3-containing building block, is involved in the present reaction system.
- Zhao, Wen-Wen,Shao, Yong-Chao,Wang, An-Ni,Huang, Jia-Li,He, Chun-Yang,Cui, Bao-Dong,Wan, Nan-Wei,Chen, Yong-Zheng,Han, Wen-Yong
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supporting information
p. 9256 - 9261
(2021/12/06)
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- Minisci aroylation of N-heterocycles using choline persulfate in water under mild conditions
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Metal persulfate mediated thermal oxidative organic transformations invariably require a higher temperature and frequently use an organic solvent. The objective of this work was to develop persulfate mediated oxidative transformations that can be performed nearly at room temperature using water as a solvent. This report describes modified Minisci aroylation of isoquinolines with arylglyoxylic acids using choline persulfate and its pre-composition (choline acetate and K2S2O8) in water at 40 °C. A few other nitrogen heterocycles were also utilized affording various aroylated products in good to excellent yields. Unlike metal persulfate that could produce metal salt byproducts, a key feature of the chemistry reported herein includes the use of environmentally benign choline persulfate containing biodegradable choline as a counter-cation, the Minisci reaction demonstrated at 40 °C in water as the only solvent, and unconventional activation of persulfate. This journal is
- Hunjan, Mandeep Kaur,Laha, Joydev K.,Tinwala, Ummehani
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p. 22853 - 22859
(2021/12/24)
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- Synthesis of Unprotected 2-Arylglycines by Transamination of Arylglyoxylic Acids with 2-(2-Chlorophenyl)glycine
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The transamination of α-keto acids with 2-phenylglycine is an effective methodology for directly synthesizing unprotected α-amino acids. However, the synthesis of 2-arylglycines by transamination is problematic because the corresponding products, 2-arylglycines, transaminate the starting arylglyoxylic acids. Herein, we demonstrate the use of commercially available l-2-(2-chlorophenyl)glycine as the nitrogen source in the transamination of arylglyoxylic acids, producing the corresponding 2-arylglycines without interference from the undesired self-transamination process.
- Inada, Haruki,Shibuya, Masatoshi,Yamamoto, Yoshihiko
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p. 11047 - 11059
(2020/10/12)
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- Novel synthesis method of benzene ring polysubstituted compound based on benzoyl formic acid
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The invention relates to a novel synthesis method of a benzene ring polysubstituted compound based on benzoyl formic acid. According to the synthesis method, an acetophenone-based benzene ring polysubstituted compound is used as a raw material, a specific
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Paragraph 0034-0040
(2020/05/30)
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- 1D Fe3O4&at;CuSiO3 composites catalyzed decarboxylative A3-coupling for propargylamine synthesis
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Highly active and stable magnetic copper catalysts were successfully achieved by magnetic induced St?ber method and subsequent hydrothermal reaction with copper ions in alkaline condition. The high content of Cu2+ as well as the unique structures of hierarchical copper silicate in the as-prepared catalysts endowed their outstanding catalytic performance. Efficient decarboxylative A3-coupling of α-keto acid, amine and alkyne was realized with the low Fe3O4&at;CuSiO3 loading. A range of propargylamines were produced in good to excellent yields under solvent-free condition. Moreover, the catalyst can be easily separated from the final organic product with an external magnet. Also, this kind of catalyst could be recycled up to six times while maintaining its activity.
- Cao, Tiantian,Feng, Huangdi,Li, Huiqiong,Miao, Teng,Wang, Fang,Zhang, Min
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supporting information
p. 1558 - 1563
(2020/07/30)
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- Photoredox Catalysis Enables Decarboxylative Cyclization with Hypervalent Iodine(III) Reagents: Access to 2,5-Disubstituted 1,3,4-Oxadiazoles
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A novel approach to 2,5-disubstituted 1,3,4-oxadiazoles derivatives via a decarboxylative cyclization reaction by photoredox catalysis between commercially available α-oxocarboxylic acids and hypervalent iodine(III) reagent is described. This powerful transformation involves the coupling reaction between two different kinds of radical species and the formation of C-N and C-O bonds.
- Li, Jian,Lu, Xue-Chen,Xu, Yue,Wen, Jin-Xia,Hou, Guo-Quan,Liu, Li
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supporting information
p. 9621 - 9626
(2020/12/21)
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- Aroylation of Electron-Rich Pyrroles under Minisci Reaction Conditions
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The development of Minisci acylation on electron-rich pyrroles under silver-free neutral conditions has been reported featuring the regioselective monoacylation of (NH)-free pyrroles. Unlike conventional Minisci conditions, the avoidance of any acid that could result in the polymerization of pyrroles was the key to success. The umpolung reactivity of the nucleophilic acyl radical, generated in situ from arylglyoxylic acid, could help explain the mechanism of product formation with electron-rich pyrroles. Alternatively, the nucleophilic substitution of the acyl radical on the electron-deficient pyrrole radical cation is proposed.
- Laha, Joydev K.,Kaur Hunjan, Mandeep,Hegde, Shalakha,Gupta, Anjali
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supporting information
p. 1442 - 1447
(2020/02/22)
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- METHOD FOR PRODUCING BENZOYL FORMIC ACID COMPOUND AND PYRIDAZINE COMPOUND
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The present invention provides an industrially-advantageous process for preparing a benzoyl formic acid compound, and an efficient process for preparing a pyridazine compound using the same process. Specifically, the present invention provides a process for preparing a compound represented by formula (2), which comprises a step (B): a step of reacting a compound represented by formula (1) with a nitrosyl sulfuric acid in water to produce the compound represented by formula (2).
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Paragraph 0097
(2020/12/18)
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- Organocatalytic Enantioselective Selenosulfonylation of a C-C Double Bond to Form Two Stereogenic Centers in an Aqueous Medium
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Organocatalytic selenosulfonylation of the C-C double bond of α,β-unsaturated ketones to construct two contiguous stereogenic centers in an aqueous medium was described. A series of α-selenyl and β-sulfonyl ketones with various functional groups were synthesized in good yields and enantioselectivities with saturated NaCl solution as the solvent. In addition, this protocol had been successfully scaled up to a decagram scale via a simple workup procedure.
- Chen, Zhili,Hu, Fangli,Huang, Shengli,Zhao, Zhengxing,Mao, Hui,Qin, Wenling
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p. 8100 - 8111
(2019/06/17)
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- Palladium-Catalyzed Primary Amine-Directed Decarboxylative Annulation of α-Oxocarboxylic Acids: Access to Indolo[1,2-a]quinazolines
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An efficient protocol for the preparation of indolo[1,2-a]quinazolines via palladium-catalyzed decarboxylative annulation of indols with α-oxocarboxylic acids has been realized by using primary amine as a directing group (DG). This transformation proceeds smoothly with exclusive regioselectivity and represents an one-pot Domino synthesis of indo-lo[1,2-a]quinazolines from α-oxocarboxylic acids. (Figure presented.).
- Jiang, Guangbin,Wang, Shoucai,Zhang, Jun,Yu, Jianwen,Zhang, Ziang,Ji, Fanghua
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supporting information
p. 1798 - 1802
(2019/03/13)
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- Electrochemical synthesis of enaminones: Via a decarboxylative coupling reaction
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An environmentally benign and efficient electrochemical synthesis of enaminones via a decarboxylative coupling reaction of α-keto acids using n-Bu4NI as a redox catalyst and electrolyte under constant current electrolysis in an undivided cell is reported. A broad vinyl azide substrate scope and high functional group tolerance are observed. A gram-scale reaction further demonstrates the practicability of the protocol. The results of cyclic voltammetry and control experiments indicate that I2 is likely the active species to initiate the oxidative decarboxylation via an acyl hypoiodite intermediate.
- Kong, Xianqiang,Liu, Yulong,Lin, Long,Chen, Qianjin,Xu, Bo
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supporting information
p. 3796 - 3801
(2019/07/31)
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- Stereospecific Nucleophilic Substitution with Arylboronic Acids as Nucleophiles in the Presence of a CONH Group
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Stereospecific nucleophilic substitution was achieved for the first time with arylboronic acids as nucleophiles. This transition-metal-free coupling between chiral α-aryl-α-mesylated acetamides and arylboronic acids provided access to a series of chiral α,α-diaryl acetamides with excellent enantioselectivity and moderate to good yields. The CONH functionality proved to be crucial for bridging the reactants and promoting the reaction. Efficient syntheses of a cannabinoid CB1 receptor ligand, the antidepressant (S)-diclofensine, and a key chiral building block of the inhibitor implitapide were successfully accomplished by using this method.
- Tian, Duanshuai,Li, Chengxi,Gu, Guoxian,Peng, Henian,Zhang, Xumu,Tang, Wenjun
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supporting information
p. 7176 - 7180
(2018/05/29)
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- Direct Acyl Radical Addition to 2 H-Indazoles Using Ag-Catalyzed Decarboxylative Cross-Coupling of α-Keto Acids
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A direct acyl radical addition to 2H-indazoles has been achieved for the first time, where the less-aromatic quinonoid 2H-indazoles readily accepted radical species to the C-3 position. Motivated by the lack of direct acylation strategy for 2H-indazoles, the current method utilizes the radical acceptability of 2H-indazoles, discovering an ambient temperature reaction to provide facile access to a diverse array of 3-acyl-2H-indazoles with three points of structural diversification in 25%-83% yields.
- Bogonda, Ganganna,Kim, Hun Young,Oh, Kyungsoo
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supporting information
p. 2711 - 2715
(2018/05/22)
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- The Synthesis of Chiral α-Aryl α-Hydroxy Carboxylic Acids via RuPHOX-Ru Catalyzed Asymmetric Hydrogenation
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A ruthenocenyl phosphino-oxazoline-ruthenium complex (RuPHOX?Ru) catalyzed asymmetric hydrogenation of α-aryl keto acids has been successfully developed, affording the corresponding chiral α-aryl α-hydroxy carboxylic acids in high yields and with up to 97% ee. The reaction could be performed on a gram scale with a relatively low catalyst loading (up to 5000 S/C) and the resulting products can be transformed to several chiral building blocks, biologically active compounds and chiral drugs. (Figure presented.).
- Guo, Huan,Li, Jing,Liu, Delong,Zhang, Wanbin
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supporting information
p. 3665 - 3673
(2017/09/11)
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- Enzymatic Resolution by a d-Lactate Oxidase Catalyzed Reaction for (S)-2-Hydroxycarboxylic Acids
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Oxidase-catalyzed kinetic resolution is important for the production of enantiopure 2-hydroxycarboxylic acids (2-HAs), which are versatile building blocks for the synthesis of many significant compounds. However, in contrast to that of (R)-2-HAs, the production of (S)-2-HA is challenging because of the lack of related oxidases. Herein, suitable enzymes were screened systematically through the analysis of numerous putative d-lactate oxidase sequences and identification of several required properties. Finally, a d-lactate oxidase from Gluconobacter oxydans 621H with advantageous characteristics, such as good solubility, broad substrate spectrum, and high stereoselectivity, was selected to resolve 2-HAs into (S)-2-HAs. A variety of (S)-2-HAs was produced successfully using this d-lactate oxidase with excellent enantiomeric excess values (>99 %). The presented screening criteria and approach for target biocatalysis suggested a guideline for the production of optically active chemicals such as (S)-2-HAs.
- Sheng, Binbin,Xu, Jing,Ge, Yongsheng,Zhang, Shuo,Wang, Danqi,Gao, Chao,Ma, Cuiqing,Xu, Ping
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p. 2630 - 2633
(2016/08/30)
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- Palladium-catalyzed ortho-acylation of N-Nitrosoanilines with α-oxocarboxylic acids: A convenient method to synthesize N-Nitroso ketones and indazoles
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An efficient and mild protocol for regioselective synthesis of N-Nitroso aryl ketones by palladium-catalyzed direct acylation of arenes using N-Nitroso as directing groups is described. This reaction proceeded smoothly and could tolerate a variety of functional groups. Moreover, this chemistry offers a convenient access to a range of indazoles.
- Zhang, Liang,Wang, Zhe,Guo, Peiyu,Sun, Wei,Li, Ya-Min,Sun, Meng,Hua, Chengwen
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supporting information
p. 2511 - 2514
(2016/05/24)
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- Asymmetric Hydrogenation of α-Substituted Acrylic Acids Catalyzed by a Ruthenocenyl Phosphino-oxazoline-Ruthenium Complex
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Asymmetric hydrogenation of various α-substituted acrylic acids was carried out using RuPHOX-Ru as a chiral catalyst under 5 bar H2, affording the corresponding chiral α-substituted propanic acids in up to 99% yield and 99.9% ee. The reaction could be performed on a gram-scale with a relatively low catalyst loading (up to 5000 S/C), and the resulting product (97%, 99.3% ee) can be used as a key intermediate to construct bioactive chiral molecules. The asymmetric protocol was successfully applied to an asymmetric synthesis of dihydroartemisinic acid, a key intermediate required for the industrial synthesis of the antimalarial drug artemisinin.
- Li, Jing,Shen, Jiefeng,Xia, Chao,Wang, Yanzhao,Liu, Delong,Zhang, Wanbin
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supporting information
p. 2122 - 2125
(2016/06/01)
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- Steric and Electronic Requirements in the Synthesis of 2,3-Dihydro-4(1H)-quinolinones by the Tandem Michael-SNAr Reaction
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The steric and electronic requirements have been investigated for the synthesis of 2,3-dihydro-4(1H)-quinolinones by the tandem Michael-SNAr reaction. Substrates bearing a single methyl group at the β-enone carbon gave excellent yields of the title compounds from both the E and Z isomers with X=H or NO2. Substrates with β,β-dimethyl substitution at the Michael terminus gave low yields of heterocyclic products in molecules having monoactivated SNAr aromatic acceptor rings (X=H) and very good yields for diactivated systems (X=NO2). For these hindered substrates, success in the final cyclization hinges on the ability of the aromatic acceptor to capture the pendant nitrogen nucleophile of the initial Michael adduct before this intermediate can revert to starting materials.
- Bunce, Richard A.,Nago, Takahiro,Abuskhuna, Suaad
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p. 1143 - 1149
(2015/08/06)
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- Carbonylative coupling of allylic acetates with aryl boronic acids
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The first allylic carbonylation reaction of allylic acetates with aryl boronic acids under carbon monoxide has been developed. Using Pd-PCy3 as a catalyst, a wide spectrum of allylic acetates was carbonylated in the presence of various aryl boronic acids, affording α,β-unsaturated aryl ketones in good to excellent yields. Preliminary studies indicate that carbon monoxide always inserts at the least substituted terminal allylic carbon and the resulting β,γ-unsaturated aryl ketones generally isomerise to the ketones obtained.
- Ma, Wei,Xue, Dong,Yu, Ting,Wang, Chao,Xiao, Jianliang
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supporting information
p. 8797 - 8800
(2015/05/20)
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- Cationic Ir/Me-BIPAM-catalyzed asymmetric intramolecular direct hydroarylation of α-ketoamides
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Asymmetric intramolecular direct hydroarylation of α-ketoamides gives various types of optically active 3-substituted 3-hydroxy-2-oxindoles in high yields with complete regioselectivity and high enantioselectivities (84-98 % ee). This is realized by the use of the cationic iridium complex [Ir(cod) 2](BArF4) and the chiral O-linked bidentate phosphoramidite (R,R)-Me-BIPAM. Carbon's got a brand new bond: Asymmetric intramolecular direct hydroarylation of α-ketoamides gives various optically active 3-substituted 3-hydroxy-2-oxindoles in high yields with complete regioselectivity and high enantioselectivities. This is realized by the use of an asymmetric cationic iridium complex formed in situ (see Scheme).
- Shirai, Tomohiko,Ito, Hajime,Yamamoto, Yasunori
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supporting information
p. 2658 - 2661
(2014/03/21)
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- Enantio- and chemoselective Br?nsted-acid/Mg(nBu) 2 catalysed reduction of α-keto esters with catecholborane
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The first enantio- and chemoselective Br?nsted-acid catalysed reduction of α-keto esters with catecholborane has been developed. The α-hydroxy esters were obtained under mild reaction conditions in virtually quantitative yields and excellent enantioselectivities. With slight modifications both enantiomers can be obtained without any loss of selectivity. This journal is the Partner Organisations 2014.
- Enders, Dieter,St?ckel, Bianca A.,Rembiak, Andreas
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supporting information
p. 4489 - 4491
(2014/04/17)
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- Decarboxylative allylation of arylglyoxylic acids with allyl alcohol
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A decarboxylative allylation of arylglyoxylic acids with allyl alcohol has been developed. In the presence of catalytic amounts of Pd(dba) 2 and PPh3, the substrates are in an esterification equilibrium with the allyl arylglyoxylates, which are continuously decarboxylated to give α,β-unsaturated ketones along with CO2 and water as the only byproducts.
- Grünberg, Matthias F.,Goo?en, Lukas J.
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p. 140 - 143
(2013/10/01)
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- Chemo- and enantioselective Bronsted acid-catalyzed reduction of α-imino esters with catecholborane
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The chemo- and enantioselective reduction of α-imino esters with catecholborane has been developed employing 10 mol% of an enantiopure BINOL-based phosphoric acid as organocatalyst. Various differently substituted aromatic α-amino acid derivatives can be
- Enders, Dieter,Rembiak, Andreas,Stoeckel, Bianca Anne
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supporting information
p. 1937 - 1942
(2013/08/23)
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- Decarboxylative allylation of glyoxylic acids with diallyl carbonate
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A catalyst system consisting of Pd(PPh3)4 and P(pTol)3 was found to effectively promote the intermolecular decarboxylative coupling of α-oxocarboxylic acids with diallyl carbonate to give α,β-unsaturated ketones. The key advantage of the new reaction protocol is that preformation of the allyl esters is not required. The reaction is believed to proceed via phosphane-mediated decarboxylation of the α-oxocarboxylates, leading to acyl anion equivalents that are allylated within the coordination sphere of the palladium catalyst. Under the reaction conditions, the double bond then migrates into conjugation with the carbonyl group. Copyright
- Manjolinho, Filipe,Gruenberg, Matthias F.,Rodriguez, Nuria,Goossen, Lukas J.
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supporting information; experimental part
p. 4680 - 4683
(2012/10/08)
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- Decarboxylative acylation of cyclic enamides with α-oxocarboxylic acids by palladium-catalyzed C-H activation at room temperature
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An efficient catalytic decarboxylative acylation of unactivated sp 2 (alkenyl) C-H bonds has been developed. Various substituted α-oxocarboxylic acids with different electronic properties react under mild conditions to afford a diverse range of β-acyl enamide products in good yields. The reaction is proposed to proceed via a cyclic vinylpalladium intermediate, facilitating the decarboxylative dehydrogenative process with enamide coupling partners.
- Wang, Hua,Guo, Li-Na,Duan, Xin-Hua
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supporting information
p. 4358 - 4361
(2012/10/29)
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- Synthesis of α,β-unsaturated ketones by Pd-catalyzed decarboxylative allylation of α-oxocarboxylates
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A palladium/p-tolylphosphine system has been developed that catalyzes the extrusion of carbon dioxide from α-oxocarboxylic acid allyl esters, leading to α,β-unsaturated ketones (see scheme). The palladium complex activates the substrate and mediates the carbon-carbon bond formation to give allyl ketones, and subsequent double bond shift to the α,β position. The actual decarboxylation step with formation of the acyl nucleophile is promoted by phosphine.
- Rodriguez, Nuria,Manjolinho, Filipe,Gruenberg, Matthias F.,Goossen, Lukas J.
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supporting information; experimental part
p. 13688 - 13691
(2012/01/15)
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- 6-Beta-(alpha-etherified oxymino)-acyl amino penicillins
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Compounds of formula (I): wherein R1 is optionally substituted phenyl and R is a cycloalkyl group having an alkyl substituent in the 1-position; or R1 is phenyl substituted by at least one fluorine atom and/or at least one trifluoromethyl group and R is hydrogen or an organic radical, and their salts and esters, are useful in the treatment of bacterial infections in humans and animals.
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