- On the Regioselectivity of 4-Nitroanisole Photosubstitution with Primary Amines. A Mechanistic and Theoretical Study
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4-Nitroanisole photoreacts with n-hexylamine and ethyl glycinate, giving rise to regioselective methoxy and nitro group photosubstitution, respectively.Mechanistic evidence indicates that the latter is produced through a SN23Ar*
- Cantos, Albert,Marquet, Jorge,Moreno-Manas, Marcial,Gonzales-Lafont, Angels,Lluch, Jose M.,Bertran, Juan
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- Reductive Amination Revisited: Reduction of Aldimines with Trichlorosilane Catalyzed by Dimethylformamide─Functional Group Tolerance, Scope, and Limitations
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Aldimines, generated in situ from aliphatic, aromatic, and heteroaromatic aldehydes and aliphatic, aromatic, and heteroaromatic primary or secondary amines, can be reduced with trichlorosilane in the presence of dimethylformamide (DMF) as an organocatalys
- Campbell, Joanna L. P.,Davies, Christopher D.,Ho?ek, Jan,Ko?ovsky, Pavel,Kysilka, Ond?ej,Popov, Kirill K.,Pour, Milan
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p. 920 - 943
(2022/01/27)
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- Water-Involved Ring-Opening of 4-Phenyl-1,2,4-triazoline-3,5-dione for “Photo-Clicked” Access to Carbamoyl Formazan Photoswitches In Situ
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Cyclic azodicarbonyl derivatives, particularly 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD), commonly serve as arenophile, dienophile, enophile and electrophile. Perplexed by its instability in aqueous environment, there are few studies focused on the transient intermediate produced by hydrolysis of PTAD to achieve synthetic significance. Herein, we describe a “photo-click” method that involves nitrile imine (NI) from diarylsydnone to capture the diazenecarbonyl-phenyl-carbamic acid (DACPA) generated by water-promoted ring-opening of PTAD. DFT calculation reveal that H-bonding interactions between PTAD and water are vital to form DACPA which exhibited an umpolung effect during ligation by nature bond orbit (NBO) analysis. The ultra-fast ligation resulted in carbamoyl formazans, as a unique Z?E photo-switchable linker on target molecules, including peptide and drugs, with excellent anti-fatigue performance. This strategy is showcased to construct highly functionalized carbamoyl formazans in situ for photo-pharmacology and material studies, which also expands the chemistry of PTAD in aqueous media.
- Zheng, Yuanqin,Zhou, Yuqiao,Zhang, Yan,Deng, Pengchi,Zhao, Xiaohu,Jiang, Shichao,Du, Guangxi,Shen, Xin,Xie, Xinyu,Su, Zhishan,Yu, Zhipeng
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supporting information
(2021/12/22)
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- Perovskite as Recyclable Photocatalyst for Annulation Reaction of N-Sulfonyl Ketimines
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A sustainable and cost-effective manner for the photocatalytic annulation reaction of N-sulfonyl ketimines with N-arylglycines to synthesize imidazolidine-fused sulfamidates (31 examples) by employing CsPbBr3 as a heterogeneous photocatalyst has been developed. The catalyst CsPbBr3 can be simply recovered from the reaction mixture and reused at least five times without an obvious reduction in its photocatalytic reactivity, exhibiting a high catalyst economic feature.
- Shi, Anzai,Sun, Kai,Chen, Xiaolan,Qu, Lingbo,Zhao, Yufen,Yu, Bing
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supporting information
p. 299 - 303
(2022/01/04)
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- Design, synthesis and biological evaluation of oxime lacking Psammaplin inspired chemical libraries as anti-cancer agents
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In this study, we attempted the chemical simplification of Psammaplin (PsA), while retaining its activity in vitro. Inspired by the previous Structure Activity Relationship (SAR) studies on various PsA analogues and relying on the fact that oxime is metabolically unstable, we initially designed and synthesized a diverse library of PsA analogues and evaluated for cytotoxic activity. Among 32 compounds of Psammaplin analogues synthesized, the compound 10b was almost equally active as parent Psammaplin in vitro.
- Ali, Kasim,Chaturvedi, Priyank,Datta, Dipak,Kumar M, Srinivas Lavanya,Meena, Sanjeev,Panda, Gautam
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- Visible-Light-Induced Oxidative α-Alkylation of Glycine Derivatives with Ethers under Metal-Free Conditions
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In this work, a visible-light-induced oxidative α-alkylation of glycine derivatives with ethers has been developed in the presence of catalytic Eosin Y. Under the blue light of a 3 W LED, a range of α-etherized glycine derivatives, including α-amino esters, α-amino ketones and α-amino amides, were achieved with good to excellent yields and functional group tolerance with tert-butyl hydroperoxide (TBHP) as oxidant at ambient temperature. The operationally easy procedure provides an economical, metal-free, and mild alternative for the synthesis of the α-etherized glycine derivatives.
- Song, Yang,Zhang, Hao,Guo, Jiabao,Shao, Yifei,Ding, Yuzhou,Zhu, Li,Yao, Xiaoquan
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p. 5914 - 5921
(2021/11/22)
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- Molecular Oxygen-Mediated Radical Alkylation of C(sp3)-H Bonds with Boronic Acids
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A direct and site-specific alkylation of (sp3)C-H bond with aliphatic boronic acid was achieved. By simply heating glycinates and amines together with alkylboronic acids under an oxygen atmosphere, a variety of unnatural α-amino acids and peptides could b
- Yang, Le,Qiu, Zhihong,Wu, Jintao,Zhao, Jianyou,Shen, Tong,Huang, Xuan,Liu, Zhong-Quan
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supporting information
p. 3207 - 3210
(2021/05/04)
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- Direct, Site-Selective and Redox-Neutral α-C?H Bond Functionalization of Tetrahydrofurans via Quantum Dots Photocatalysis
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As one of the most ubiquitous bulk reagents available, the intrinsic chemical inertness of tetrahydrofuran (THF) makes direct and site-selective C(sp3)?H bond activation difficult, especially under redox neutral condition. Here, we demonstrate that semiconductor quantum dots (QDs) can activate α-C?H bond of THF via forming QDs/THF conjugates. Under visible light irradiation, the resultant alkoxyalkyl radical directly engages in radical cross-coupling with α-amino radical from amino C?H bonds or radical addition with alkene or phenylacetylene, respectively. In contrast to stoichiometric oxidant or hydrogen atom transfer reagents required in previous studies, the scalable benchtop approach can execute α-C?H bond activation of THF only by a QD photocatalyst under redox-neutral condition, thus providing a broad of value added chemicals starting from bulk THFs reagent.
- Chen, Bin,Ci, Rui-Nan,Huang, Cheng,Liu, Zan,Qiao, Jia,Song, Zi-Qi,Tung, Chen-Ho,Wu, Li-Zhu
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supporting information
p. 27201 - 27205
(2021/11/16)
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- Selective carbene transfer to amines and olefins catalyzed by ruthenium phthalocyanine complexes with donor substituents
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Electron-rich ruthenium phthalocyanine complexes were evaluated in carbene transfer reactions from ethyl diazoacetate (EDA) to aromatic and aliphatic olefins as well as to a wide range of aromatic, heterocyclic and aliphatic amines for the first time. It was revealed that the ruthenium octabutoxyphthalocyanine carbonyl complex [(BuO)8Pc]Ru(CO) is the most efficient catalyst converting electron-rich and electron-poor aromatic olefins to cyclopropane derivatives with high yields (typically 80-100%) and high TON (up to 1000) under low catalyst loading and nearly equimolar substrate/EDA ratio. This catalyst shows a rare efficiency in the carbene insertion into amine N-H bonds. Using a 0.05 mol% catalyst loading, a high amine concentration (1 M) and 1.1 eq. of EDA, a number of structurally divergent amines were selectively converted to mono-substituted glycine derivatives with up to quantitative yields and turnover numbers reaching 2000. High selectivity, large substrate scope, low catalyst loading and practical reaction conditions place [(BuO)8Pc]Ru(CO) among the most efficient catalysts for the carbene insertion into amines.
- Cailler, Lucie P.,Kroitor, Andrey P.,Martynov, Alexander G.,Gorbunova, Yulia G.,Sorokin, Alexander B.
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supporting information
p. 2023 - 2031
(2021/02/26)
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- Unnatural α-Amino Acid Synthesized through α-Alkylation of Glycine Derivatives by Diacyl Peroxides
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We have developed a protocol for catalyst- and additive-free α-alkylation reactions of glycine derivatives with diacyl peroxides, which proceed by a pathway involving addition of alkyl radicals to imine intermediates. The diacyl peroxide substrate acts as both alkylation agent and oxidizing agent, which means it is atom-economical. It was applied to various glycine derivatives, dipeptides, and a 3,4-dihydroquinoxalin-2(1H)-one derivative and could be carried out on a gram scale, indicating its utility for late-stage functionalization.
- Tian, Hao,Xu, Wentao,Liu, Yuxiu,Wang, Qingmin
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supporting information
p. 5005 - 5008
(2020/07/04)
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- Photoinduced iodine-mediated tandem dehydrogenative Povarov cyclisation/C-H oxygenation reactions
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We report metal-free, photoinduced aerobic tandem dehydrogenative Povarov cyclisation/Csp3-H oxygenation reactions between N-aryl glycine esters and α-substituted styrenes, which efficiently lead to 4,4-disubstituted dihydroquinoline-3-ones under mild conditions. The reactions are mediated by iodine along with visible light irradiation, which allows for the in situ generation of the essential Br?nsted acid HI, to catalyse the key imine [4+2]-cycloaddition.
- Brasholz, Malte,Schendera, Eva,Villinger, Alexander
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supporting information
p. 6912 - 6915
(2020/10/02)
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- Exploiting Synergistic Catalysis for an Ambient Temperature Photocycloaddition to Pyrazoles
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Sydnone-based cycloaddition reactions are a versatile platform for pyrazole synthesis, however they operate under harsh conditions (high temperature and long reaction times). Herein we report a strategy that addresses this limitation utilizing the synergistic combination of organocatalysis and visible-light photocatalysis. This new approach proceeds under ambient conditions and with excellent levels of regiocontrol. Mechanistic studies suggest that photoactivation of sydnones, rather than enamines, is key to the successful implementation of this process.
- Lakeland, Christopher P.,Watson, David W.,Harrity, Joseph P. A.
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supporting information
p. 155 - 159
(2019/12/11)
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- Copper-Catalyzed Annulation of Oxime Acetates with α-Amino Acid Ester Derivatives: Synthesis of 3-Sulfonamido/Imino 4-Pyrrolin-2-ones
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A copper-catalyzed annulation of oxime acetates and α-amino acid ester derivatives for the easy preparation of 4-pyrrolin-2-ones bearing a 3-amino group has been developed. This process features the oxidation of amines with oxime esters as the internal oxidant to produce the active 1,3-dinucleophilic and 1,2-dielectrophilic species concurrently. The subsequent nucleophilic cyclization realizes the efficient construction of 4-pyrrolin-2-one derivatives.
- Miao, Chun-Bao,Zheng, An-Qi,Zhou, Li-Jin,Lyu, Xinyu,Yang, Hai-Tao
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supporting information
p. 3381 - 3385
(2020/04/21)
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- Preparation method of 4-AA key intermediate epoxy butylamide
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The invention relates to a preparation method of 4-AA key intermediate epoxy butylamide. The preparation method comprises the steps that (1) synthesis of epoxy butyric acid is conducted: a starting material L-threonine is cyclized under diazotization and
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Paragraph 0020; 0022
(2019/11/12)
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- Photo-polymerization properties of type-II photoinitiator systems based on 2-chlorohexaaryl biimidazole (o-Cl-HABI) and various N-phenylglycine (NPG) derivatives
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A series of p-substituted NPG derivatives (Cl-NPG, OMe-NPG and NO2-NPG) comprising different push-pull characteristics have been synthesized and characterized. The NPG derivatives have good thermal stability and red shifted absorption when comp
- Chen, Yung-Chung,Kuo, Yuan-Tsung,Ho, Tsung-Han
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p. 190 - 197
(2019/01/21)
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- Metal-free synthesis of pyridin-2-yl ureas from 2-aminopyridinium salts
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An unprecedented base promoted domino approach has been developed for the synthesis of pyridin-2-yl urea derivatives via the reaction of 2-aminopyridinium salts and arylamines. The developed strategy tolerated a wide range of functional groups and afforded pyridin-2-yl ureas in moderate to good yields. The reaction was postulated to involve tandem cyclization, intermolecular nucleophilic addition, ring opening, and demethylation.
- Saroj,Patel, Om P.S.,Rangan, Krishnan,Kumar, Anil
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supporting information
(2019/07/23)
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- Discovery of Fluorogenic Diarylsydnone-Alkene Photoligation: Conversion of ortho-Dual-Twisted Diarylsydnones into Planar Pyrazolines
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A small library of diarylsydnones (DASyds) was constructed based on aryl-pairing combinations and subjected to click reaction toward alkenes under photoirradiation with high efficiency. We were able to demonstrate the utility of DASyds for highly fluorescent turn-on ligation targeting the trans-cyclooct-4-en-1-ol moieties on protein.
- Zhang, Linmeng,Zhang, Xiaocui,Yao, Zhuojun,Jiang, Shichao,Deng, Jiajie,Li, Bo,Yu, Zhipeng
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supporting information
p. 7390 - 7394
(2018/06/13)
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- Functionalization of N-arylglycine esters: Electrocatalytic access to C-C bonds mediated by n-Bu4NI
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An efficient electrocatalytic functionalization of N-arylglycine esters is reported. The protocol proceeds in an undivided cell under constant current conditions employing the simple, cheap and readily available n-Bu4NI as the mediator. In addition, it is demonstrated that the mediated process is superior to the direct electrochemical functionalization.
- Luo, Mi-Hai,Jiang, Yang-Ye,Xu, Kun,Liu, Yong-Guo,Sun, Bao-Guo,Zeng, Cheng-Chu
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supporting information
p. 499 - 505
(2018/03/21)
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- Arylamino containing hydroxamic acids as potent urease inhibitors for the treatment of Helicobacter pylori infection
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A novel series of aniline-containing hydroxamic acids were designed, synthesized and evaluated as anti-virulence agents for the treatment of gastritis and gastric ulcer caused by Helicobacter pylori. In vitro enzyme-based screen together with in vivo assays and structure?activity relationship (SAR) studies led to the discovery of three potent urease inhibitors 3-(3,5-dichlorophenylamino)–N-hydroxypropanamide (3a), 3-(2-chlorophenylamino)–N-hydroxypropanamide (3d) and 3-(2,4-dichlorophenylamino)–N-hydroxypropanamide (3n). Compounds 3a, 3d and 3n showed excellent urease inhibition with IC50 values 0.043 ± 0.005, 0.055 ± 0.008 and 0.018 ± 0.002 μM, and significantly depressed gastritis developing at the dose of 32 mg/kg b. i.d with eradication rates of H. pylori reaching 92.3, 84.6 and 100%, respectively. Preliminary safety studies (acute toxicity in mice) disclosed that 3a, 3d and 3n was well-tolerated in KM mice with LD50s of 2982.8, 3349.4 and 3126.9 mg/kg, respectively. Collectively, the data obtained in this study indicate that 3a, 3d and 3n, in particular 3n, could considered as promising candidates for the potential treatment of H. pylori caused gastritis and gastric ulcer, and hence merit further studies.
- Liu, Qi,Shi, Wei-Kang,Ren, Shen-Zhen,Ni, Wei-Wei,Li, Wei-Yi,Chen, Hui-Min,Liu, Pei,Yuan, Jing,He, Xiao-Su,Liu, Jia-Jia,Cao, Peng,Yang, Pu-Zhen,Xiao, Zhu-Ping,Zhu, Hai-Liang
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p. 126 - 136
(2018/07/13)
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- Dual role of Cu2O nanocubes as templates and networking catalysts for hollow and microporous Fe-porphyrin networks
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Cu2O nanocubes were used for the synthesis of hollow and microporous Fe porphyrin networks (H-MFePN). In this synthesis, Cu2O nanocubes performed not only as networking catalysts but also as shape controlling templates. MFePN were formed on the surface of the Cu2O nanocubes through azide-alkyne cycloaddition of tetrakis(4-ethynylphenyl) Fe-porphyrin with 1,4-diazidobenzene. H-MFePN showed excellent catalytic activities in carbene insertion into N-H bonds, maintaining their activities during five recycle tests.
- Kang, Daye,Ko, Ju Hong,Choi, Jaewon,Cho, Kyoungil,Lee, Sang Moon,Kim, Hae Jin,Ko, Yoon-Joo,Park, Kang Hyun,Son, Seung Uk
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supporting information
p. 2598 - 2601
(2017/03/09)
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- Application of Off-Rate Screening in the Identification of Novel Pan-Isoform Inhibitors of Pyruvate Dehydrogenase Kinase
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Libraries of nonpurified resorcinol amide derivatives were screened by surface plasmon resonance (SPR) to determine the binding dissociation constant (off-rate, kd) for compounds binding to the pyruvate dehydrogenase kinase (PDHK) enzyme. Parallel off-rate measurements against HSP90 and application of structure-based drug design enabled rapid hit to lead progression in a program to identify pan-isoform ATP-competitive inhibitors of PDHK. Lead optimization identified selective sub-100-nM inhibitors of the enzyme which significantly reduced phosphorylation of the E1α subunit in the PC3 cancer cell line in vitro.
- Brough, Paul A.,Baker, Lisa,Bedford, Simon,Brown, Kirsten,Chavda, Seema,Chell, Victoria,D’Alessandro, Jalanie,Davies, Nicholas G. M.,Davis, Ben,Le Strat, Loic,Macias, Alba T.,Maddox, Daniel,Mahon, Patrick C.,Massey, Andrew J.,Matassova, Natalia,McKenna, Sean,Meissner, Johannes W. G.,Moore, Jonathan D.,Murray, James B.,Northfield, Christopher J.,Parry, Charles,Parsons, Rachel,Roughley, Stephen D.,Shaw, Terry,Simmonite, Heather,Stokes, Stephen,Surgenor, Allan,Stefaniak, Emma,Robertson, Alan,Wang, Yikang,Webb, Paul,Whitehead, Neil,Wood, Mike
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supporting information
p. 2271 - 2286
(2017/04/03)
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- REMOVAL OF SENESCENCE-ASSOCIATED MACROPHAGES
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In various aspects and embodiments provided are compounds, compositions and methods relating to aging, senescent cells (SCs) and/or senescence associate macrophages (SAMs). In certain aspects and embodiments provided are compounds and compositions that selectively kill or reprogram senescent cells (SCs) and or senescence associate macrophages (SAMs) and associated methods. In some embodiments, the compounds compositions and methods treat or reverse aging and/or age-related diseases.
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Paragraph 0319; 0320
(2017/12/15)
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- Access to α-Amino Acid Esters through Palladium-Catalyzed Oxidative Amination of Vinyl Ethers with Hydrogen Peroxide as the Oxidant and Oxygen Source
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A novel and convenient palladium catalytic system for the synthesis of α-amino acid esters from simple starting materials is reported. Hydrogen peroxide not only acts as the green oxidant, but also as the oxygen source. This strategy for the conversion of amines and vinyl ethers into highly functionalized and structurally diverse α-amino acid esters is characterized by the simplicity of the experimental procedure, mild reaction conditions, high atom economy, scalability, and practicability.
- Ouyang, Lu,Li, Jianxiao,Zheng, Jia,Huang, Jiuzhong,Qi, Chaorong,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 15926 - 15930
(2017/11/23)
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- Derivatives and application to the asymmetric synthesis of unnatural α-amino acid derivative
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We describe herein a manganese(IV) oxide-mediated oxidation of N-p-methoxyphenyl (PMP)-protected glycine derivatives for the synthesis of a-imino carboxylic acid derivatives. Using this methodology, utilization of unstable glyoxic acid derivatives was avoided. Furthermore, using this methodology we synthesized novel a-imino carboxylic acid derivatives such as a-imino phenyl ester, perfluoroalkyl etsers, imides, and thioester. The asymmetric Mannich reaction of those novel imine derivatives with 1,3-dicarbonyl compound is also described, and the novel a-imino imide gave improved chemical yield and stereoselectivity compared with those obtained by the use of the conventional a-imino ester-type substrate.
- Inokuma, Tsubasa,Jichu, Takahisa,Nishida, Kodai,Shigenaga, Akira,Otaka, Akira
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p. 573 - 581
(2017/06/07)
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- A convenient method for preparation of α-imino carboxylic acid derivatives and application to the asymmetric synthesis of unnatural α-amino acid derivative
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We describe herein a manganese(IV) oxide-mediated oxidation of N-p-methoxyphenyl (PMP)-protected glycine derivatives for the synthesis of α-imino carboxylic acid derivatives. Using this methodology, utilization of unstable glyoxic acid derivatives was avo
- Inokuma, Tsubasa,Jichu, Takahisa,Nishida, Kodai,Shigenaga, Akira,Otaka, Akira
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p. 573 - 581
(2019/12/26)
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- Synthesis of aminopyrazoles from sydnones and ynamides
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Aminopyrazoles are prepared from readily accessible sydnones and sulfonyl ynamides using either a copper-mediated sydnone alkyne cycloaddition (CuSAC) or in situ generated strained cyclic ynamides.
- Wezeman,Comas-Barceló,Nieger,Harrity,Br?se
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supporting information
p. 1575 - 1579
(2017/02/23)
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- Copper Triflate Catalyzed Oxidative α-Allylation of Glycine Derivatives
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Copper triflate catalyzed oxidative C-H functionalization of glycine derivatives with allyltributyltin has been established using oxygen or tert -butyl hydroperoxide as oxidant. Various glycine esters and glycine amides were suitable substrates for this oxidative allylation reaction and afforded the desired homoallylic amines in moderate to good yields.
- Chen, Ting-Ting,Cai, Chun
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supporting information
p. 1368 - 1372
(2017/06/27)
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- Engineering of RuMb: Toward a Green Catalyst for Carbene Insertion Reactions
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The small, stable heme protein myoglobin (Mb) was modified through cofactor substitution and mutagenesis to develop a new catalyst for carbene transfer reactions. The native heme was removed from wild-type Mb and several Mb His64 mutants (H64D, H64A, H64V), and the resulting apoproteins were reconstituted with ruthenium mesoporphyrin IX (RuMpIX). The reconstituted proteins (RuMb) were characterized by UV-vis and circular dichroism spectroscopy and were used as catalysts for the N-H insertion of aniline derivatives and the cyclopropanation of styrene derivatives. The best catalysts for each reaction were able to achieve turnover numbers (TON) up to 520 for the N-H insertion of aniline, and 350 TON for the cyclopropanation of vinyl anisole. Our results show that RuMb is an effective catalyst for N-H insertion, with the potential to further increase the activity and stereoselectivity of the catalyst in future studies. Compared to native Mb ("FeMb"), RuMb is a more active catalyst for carbene transfer reactions, which leads to both heme and protein modification and degradation and, hence, to an overall much-reduced lifetime of the catalyst. This leads to lower TONs for RuMb compared to the iron-containing analogues. Strategies to overcome this limitation are discussed. Finally, comparison is also made to FeH64DMb and FeH64AMb, which have not been previously investigated for carbene transfer reactions.
- Wolf, Matthew W.,Vargas, David A.,Lehnert, Nicolai
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p. 5623 - 5635
(2017/05/22)
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- Phosphorylation of Glycine Derivatives via Copper(I)-Catalyzed Csp3?H Bond Functionalization
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A simple and efficient one-pot approach has been developed for a copper-catalyzed phosphorylation of glycine derivatives under air and at room temperature. The present cross-dehydrogenative coupling allows various methoxyphenyl-protected glycine derivativ
- Zhi, Huizhen,Ung, Sosthene Pierre-Marie,Liu, Yun,Zhao, Liang,Li, Chao-Jun
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supporting information
p. 2553 - 2557
(2016/08/16)
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- MYOGLOBIN-BASED CATALYSTS FOR CARBENE TRANSFER REACTIONS
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Methods are provided for carrying out carbene transfer transformations such as olefin cyclopropanation reactions, carbene heteroatom-H insertion reactions (heteroatom = N, S, Si), sigmatropic rearrangement reactions, and aldehyde olefination reactions with high efficiency and selectivity by using a novel class of myoglobin-based biocatalysts. These methods are useful for the synthesis of a variety of organic compounds which contain one or more new carbon-carbon or carbon-heteroatom (N, S, or Si) bond. The methods can be applied for conducting these transformations in vitro (i.e., using the biocatalyst in isolated form) and in vivo (i.e., using the biocatalyst in a whole cell system).
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Paragraph 0071; 00266
(2016/06/14)
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- Enantioselective synthesis of arylglycine derivatives by direct C-H oxidative cross-coupling
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A new method for the synthesis of chiral α-amino acid derivatives by enantioselective C-H arylation of N-aryl glycine esters with aryl boric acids in the presence of a chiral Pd(ii)-catalyst has been developed. This work successfully integrates the direct C-H oxidation with asymmetric arylation and exhibits excellent enantioselectivity. This journal is
- Wei, Xiao-Hong,Wang, Gang-Wei,Yang, Shang-Dong
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supporting information
p. 832 - 835
(2015/02/05)
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- Silver-prompted carbonitration of acrylamides for the synthesis of nitrating oxindoles
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A silver-prompted carbonitration of alkenes involving concomitant direct C-H functionalization and C-N bond formation to synthesize nitrating oxindoles has been developed. The CR TH2 receptor antagonist skeleton can be obtained from one of the products with further modification.
- Wei, Xiao-Hong,Wu, Quan-Xiang,Yang, Shang-Dong
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supporting information
p. 1417 - 1421
(2015/06/16)
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- Myoglobin-catalyzed intermolecular carbene N-H insertion with arylamine substrates
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Engineered variants of the heme-containing protein myoglobin can efficiently catalyze the insertion of α-diazo esters into the N-H bond of arylamines, featuring a combination of high chemoselectivity, elevated turnover numbers, and broad substrate scope.
- Sreenilayam, Gopeekrishnan,Fasan, Rudi
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p. 1532 - 1534
(2015/08/03)
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- 4-Halogeno-sydnones for fast strain promoted cycloaddition with bicyclo-[6.1.0]-nonyne
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New sydnone derivatives have been synthesized and screened for their capacity to undergo fast copper-free cycloaddition reaction with bicyclo-[6.1.0]-nonyne. The influences of substitution in positions N-3 and C-4 of sydnones have been particularly studied leading to the identification of highly reactive partners for bio-orthogonal ligation reactions.
- Plougastel, Lucie,Koniev, Oleksandr,Specklin, Simon,Decuypere, Elodie,Créminon, Christophe,Buisson, David-Alexandre,Wagner, Alain,Kolodych, Sergii,Taran, Frédéric
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supporting information
p. 9376 - 9378
(2014/08/05)
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- One-pot synthesis of 1,4-disubstituted pyrazoles from arylglycines via copper-catalyzed sydnone-alkyne cycloaddition reaction
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A robust method for constructing 1,4-pyrazoles from arylglycines was developed using the copper-catalyzed sydnone-alkyne cycloaddition reaction. The procedure offers a straightforward and general route to the pyrazole heterocycle through a three-step one-pot procedure.
- Specklin, Simon,Decuypere, Elodie,Plougastel, Lucie,Aliani, Soifia,Taran, Frédéric
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p. 7772 - 7777
(2014/10/15)
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- Cytochrome P450-catalyzed insertion of carbenoids into N-H bonds
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Expanding nature's catalytic repertoire to include reactions important in synthetic chemistry will open new opportunities for 'green' chemistry and biosynthesis. We demonstrate the first enzyme-catalyzed insertion of carbenoids into N-H bonds. This type of bond disconnection, which has no counterpart in nature, can be mediated by variants of the cytochrome P450 from Bacillus megaterium. The N-H insertion reaction takes place in water, provides the desired products in 26-83% yield, forms the single addition product exclusively, and does not require slow addition of the diazo component.
- Wang, Z. Jane,Peck, Nicole E.,Renata, Hans,Arnold, Frances H.
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p. 598 - 601
(2014/01/17)
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- Iridium porphyrin catalyzed N-H insertion reactions: Scope and mechanism
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Ir(TTP)CH3 catalyzed N-H insertion reactions between ethyl diazoacetate (EDA) or methyl phenyldiazoacetate (MPDA) and a variety of aryl, aliphatic, primary, and secondary amines to generate substituted glycine esters with modest to high yields. Aniline substrates generally gave yields above 80%, with up to 105 catalyst turnovers, and without slow addition of the diazo reagent. Good yields were also achieved with aliphatic amines, though higher catalyst loadings and slow addition of the amine were necessary in some cases. Primary amines reacted with EDA to generate both single- and double-insertion products, either of which could be produced selectively in high yield with the proper choice of stoichiometric ratios and reaction temperature. Notably, mixed trisubstituted amines, RN(CH2CO2Et) (CHPhCO2Me), were generated from the insertion of 1 equiv of EDA and 1 equiv of MPDA into primary amines. The N-H insertion mechanism was examined using substrate competition studies, trapping experiments, and multiple spectroscopic techniques. Substrate competition studies using pairs of amines with EDA or MPDA revealed Hammett correlations with respective slopes of ρ = 0.15 and ρ+ = -0.56 as well as kinetic isotope ratios of k H/kD = 1.0 ± 0.2 and 2.7 ± 0.2. Competitive amine binding to the iridium center was demonstrated by kinetics and equilibrium binding studies. Equilibrium binding constants ranged from 102 to 105. Monitoring the reaction by absorption spectroscopy revealed a transient metalloporphyrin complex. The lifetime of this species was dependent on the nature of the amine substrate, which suggests that the catalytic cycle proceeds through a metal-ylide intermediate.
- Anding, Bernie J.,Woo, L. Keith
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p. 2599 - 2607
(2013/06/26)
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- Direct amide formation from N-arylglycine ethyl esters and carboxylic acids catalysed by phenylboronic acid
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The phenylboronic acid-catalysed reaction of an N-arylglycine ethyl ester with various carboxylic acids, including N-acyl-N-phenylglycines, directly affords an amide or a dipeptide in 13-73% yields.
- Huang, Wenhua,Sha, Wen-Bin
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p. 460 - 463
(2013/09/12)
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- Iron-catalyzed oxidative tandem reactions with TEMPO oxoammonium salts: Synthesis of dihydroquinazolines and quinolines
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A straightforward iron-catalyzed divergent oxidative tandem synthesis of dihydroquinazolines and quinolines from N-alkylanilines using a TEMPO oxoammonium salt as a mild and nontoxic oxidant has been developed. Fe(OTf) 2 was the Lewis acid cata
- Rohlmann, Renate,Stopka, Tobias,Richter, Heinrich,Garcia Mancheno, Olga
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p. 6050 - 6064
(2013/07/26)
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- Novel pyrrole compounds
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There are provided inter alia compounds of formula (I) wherein R1, R2, R3, R4a and R4b are as defined in the specification and their use in therapy, especially in the treatment of bacterial (e.g. pneumococcal) infections
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Paragraph 0161
(2013/06/27)
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- NOVEL PYRROLE DERIVATIVES
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There are provided inter alia compounds of formula (I) wherein R1, R2, R3, R4a and R4b are as defined in the specification and their use in therapy, especially in the treatment of bacterial (e.g. pneumococcal) infections.
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Page/Page column 44
(2013/06/27)
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- Regioselective reaction: Synthesis, characterization and pharmacological activity of some new Mannich and Schiff bases containing sydnone
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A novel series of 1-substituted aminomethyl-3-[1-(4-isobutylphenyl)ethyl]- 4-(3-aryl-4-sydnonylidene) amino-1,2,4-triazol-5-thiones (9), was prepared from the 3-[1-(4-isobutylphenyl)ethyl]-4-(3-aryl-4-sydnonylidene) amino 5-mercapto-1,2,4-triazoles (8) by aminomethylation with formaldehyde and secondary amine. The structures of Schiff bases (8) and Mannich bases (9) were characterized on the basis of IR, NMR, mass spectra1 data and elemental analysis. The newly synthesized compounds were screened for their anti-inflammatory and analgesic activities. Mannich bases (9) carrying piperidine and morpholine residues showed promising anti-inflammatory and analgesic activity.
- Nithinchandra,Kalluraya,Aamir,Shabaraya
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experimental part
p. 597 - 604
(2012/09/11)
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- E- and Z-Stereoselectivity in the preparation of enamides from glycidyl sulfonamides and carbamates
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Treatment of glycidyl sulfonamides with LDA delivers the corresponding enesulfonamide with good selectivity for the E-isomer, whereas the corresponding carbamates exhibit selectivity for the Z-enecarbamate. An E1cB elimination mechanism proceeding from a
- Brown, Jack A.,Chudasama, Vijay,Giles, Melvyn E.,Gill, Duncan M.,Keegan, Philip S.,Kerr, William J.,Munday, Rachel H.,Griffin, Karen,Watts, Andrew
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supporting information; experimental part
p. 509 - 511
(2012/02/01)
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- Synthesis of 2 H-indazoles by the [3 + 2] dipolar cycloaddition of sydnones with arynes
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A rapid and efficient synthesis of 2H-indazoles has been developed using a [3 + 2] dipolar cycloaddition of sydnones and arynes. A series of 2H-indazoles have been prepared in good to excellent yields using this protocol, and subsequent Pd-catalyzed coupl
- Fang, Yuesi,Wu, Chunrui,Larock, Richard C.,Shi, Feng
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experimental part
p. 8840 - 8851
(2012/01/02)
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- Cross-dehydrogenative coupling reactions by transition-metal and aminocatalysis for the synthesis of amino acid derivatives
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The direct approach: The title coupling reactions of N-aryl glycine esters with unmodified ketones occurred smoothly in the presence of tert-butyl hydroperoxide (TBHP) or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) under mild conditions (see scheme). The oxidant used for C-H activation determined the selectivity of the reactions for a particular type of ketone substrate. Copyright
- Xie, Jin,Huang, Zhi-Zhen
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supporting information; experimental part
p. 10181 - 10185
(2011/02/27)
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- A water-soluble ruthenium glycosylated porphyrin catalyst for carbenoid transfer reactions in aqueous media with applications in bioconjugation reactions
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Water-soluble [RuII(4-Glc-TPP)(CO)] (1, 4-Glc-TPP ) = meso-tetrakis(4-(β-D-glucosyl)phenyl)porphyrinato dianion) is an active catalyst for the following carbenoid transfer reactions in aqueous media with good selectivities and up to 100% conversions: intermolecular cyclopropanation of styrenes (up to 76% yield), intramolecular cyclopropanation of an allylic diazoacetate (68% yield), intramolecular ammonium/ sulfonium ylide formation/[2,3]-sigmatroptic rearrangement reactions (up to 91% yield), and intermolecular carbenoid insertion into N-H bonds of primary arylamines (up to 83% yield). This ruthenium glycosylated porphyrin complex can selectively catalyze alkylation of the N-terminus of peptides (8 examples) and mediate N-terminal modification of proteins (four examples) using a fluorescent-tethered diazo compound (15). A fluorescent group was conjugated to ubiquitin via 1-catalyzed alkene cyclopropanation with 15 in aqueous solution in two steps: (1) incorporation of an alkenic group by the reaction of N-hydroxysuccinimide ester 19 with ubiquitin and (2) cyclopropanation of the alkene-tethered Lys 6 ubiquitin (23) with the fluorescentlabeled diazoacetate 15 in the presence of a catalytic amount of 1. The corresponding cyclopropanation product (24) was obtained with -55% conversion based on MALDI-TOF mass spectrometry. The products 23, 24, and the N-terminal modified peptides and proteins were characterized by LC-MS/MS and/or SDS-PAGE analyses.
- Ho, Chi-Ming,Zhang, Jun-Long,Zhou, Cong-Ying,Chan, On-Yee,Yan, Jessie Jing,Zhang, Fu-Yi,Huang, Jie-Sheng,Che, Chi-Ming
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supporting information; scheme or table
p. 1886 - 1894
(2010/04/25)
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- Cobalt(II), nickel(II), copper(II), zinc(II) and hafnium(IV) complexes of N′-(furan-3-ylmethylene)-2-(4-methoxyphenylamino)acetohydrazide
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Cobalt(II), nickel(II), copper(II), zinc(II) and hafnium(IV) complexes of furan-2-carbaldehyde 4-methoxy-N-anilinoacetohydrazone were synthesized and characterized by elemental and thermal (TG and DTA) analyses, IR, UV-vis and 1H NMR spectra as well as magnetic moment and molar conductivity. Mononuclear complexes are obtained with 1:1 molar ratio except complexes 3 and 9 which are obtained with 1:2 molar ratios. The IR spectra of ligand and metal complexes reveal various modes of chelation. The ligand behaves as a neutral bidentate one and coordination occurs via the carbonyl oxygen atom and azomethine nitrogen atom. The ligand behaves also as a monobasic tridentate one and coordination occurs through the enolic oxygen atom, azomethine nitrogen atom and the oxygen atom of furan ring. Moreover, the ligand behaves as a neutral tridentate and coordination occurs via the carbonyl oxygen, azomethine nitrogen and furan oxygen atoms as well as a monobasic bidentate and coordination occurs via the enolic oxygen atom and azomethine nitrogen atom. The electronic spectra and magnetic moment measurements reveal that all complexes possess octahedral geometry except the copper complex 10 possesses a square planar geometry. The thermal studies showed the type of water molecules involved in metal complexes as well as the thermal decomposition of some metal complexes.
- Emam, Sanaa M.,El-Saied, Fathy A.,Abou El-Enein, Saeyda A.,El-Shater, Heba A.
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experimental part
p. 291 - 297
(2009/04/13)
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- Synthesis and characterization of Cu(II), Ni(II), Co(II), Mn(II), Zn(II), Ru(III), Hf(IV) and ZrO(II) complexes of 2-thiophenylidene-N-4-methoxy anilinoacetohydrazone
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A new hydrazone ligand (HL), [2-(4-methoxyphenylamino)-N'-(thiophen-2-yl- methylene)acetohydrazide], was prepared and characterized. The ligand reacted with Cu(II), Ni(II), Co(II), Mn(II), Zn(II), Hf(IV), Ru(III) and ZrO(II) ions to yield mononuclear comp
- El-Saied,Abou El-Enein,Emam,El-Shater
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experimental part
p. 1871 - 1883
(2010/07/04)
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- Convenient access to 1,3,4-trisubstituted pyrazoles carrying 5-nitrothiophene moiety via 1,3-dipolar cycloaddition of sydnones with acetylenic ketones and their antimicrobial evaluation
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Novel 1-aryl-3-(5-nitro-2-thienyl)-4-aroyl-pyrazoles 7 have been synthesized by the 1,3-dipolar cycloaddition of 3-arylsydnones 3 with 1-aryl-3-(5-nitro-2-thienyl)-2-propyn-1-ones 6. The newly synthesized compounds were well characterized by elemental analysis, IR, 1H NMR and mass spectral studies. They were also screened for their antibacterial and antifungal activities against a variety of microorganisms and the results of such studies have been discussed in this article.
- Satheesha Rai,Kalluraya, Balakrishna,Lingappa,Shenoy, Shaliny,Puranic, Vedavati G.
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p. 1715 - 1720
(2008/12/20)
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- Iron(III) corroles and porphyrins as superior catalysts for the reactions of diazoacetates with nitrogen- or sulfur-containing nucleophilic substrates: Synthetic uses and mechanistic insights
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A thorough mechanistic investigation has been performed on the reactions of primary and secondary amines with diazoacetates, which proceed uniquely quickly and efficiently when catalyzed by iron(III) corroles and porphyrins. Two major differences in relation to other metal-based catalysts are that the iron complexes are not poisoned by excess amine and that metal-carbene intermediates are apparently not involved in the reaction pathway. The results instead point towards nitrogen ylide intermediates formed by nucleophilic attack of the amines on diazoacetate-coordinated iron complexes. Nitrogen ylides are also formed when allyl- and propargylsubstituted tertiary amines react with diazoacetates, a scenario that smoothly leads to 2,3-rearrangement reaction products with catalytic amounts of the iron(III) complexes. Similar findings regarding the superiority of the iron-(III) complexes (in terms of catalyst loading, chemical yields, and reaction conditions) were obtained with thiols (S-H insertion) and sulfides (2,3-rear-rangement reactions), which suggest similar mechanisms operate in these cases.
- Aviv, Iris,Gross, Zeev
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scheme or table
p. 3995 - 4005
(2009/05/26)
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- PROCESSES FOR THE PREPARATION OF PENEMS AND ITS INTERMEDIATE
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The present invention relates to a process for the preparation of 4-acetoxy azetidinone of Formula I, wherein R2 is hydrogen or a suitable amino protecting group and P is suitable hydroxy protecting group, and to the use of these compounds as intermediates for the preparation of ?-lactam antibiotics that possess the carbapenem and penem ring systems. 4-acetoxy azetidinone of Formula I is a key intermediate in the synthesis of ?-lactam antibiotics which are commonly prescribed antimicrobial agents having activity against a wide range of both Gram-positive and Gram-negative bacteria.
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Page/Page column 18-19
(2008/06/13)
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