- Synthesis of thiochromans via [3+3] annulation of aminocyclopropanes with thiophenols
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We report the one-pot synthesis of 4-amino thiochromans using simple aminocyclopropanes and thiophenols through a formal [3+3] annulation reaction. This reaction proceeds under mild conditions with good functional group tolerance. The thiochroman core was
- Wang, Ming-Ming,Jeon, Seongmin,Waser, Jer?me
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- Diamine Synthesis via the Nitrogen-Directed Azidation of σ- And π-C-C Bonds
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Diamines are essential building blocks for the synthesis of agrochemicals, drugs, and organic materials, yet their synthesis remains challenging, as both nitrogens need to be differentiated and diverse substitution patterns (1,2, 1,3, or 1,4) are required. We report herein a new strategy giving access to 1,2, 1,3, and 1,4 amido azides as orthogonally protected diamines based on the nitrogen-directed diazidation of alkenes, cyclopropanes, and cyclobutanes. Commercially available copper thiophene-2-carboxylate (CuTc, 2 mol %) as catalyst promoted the diazidation of both πand σ C-C bonds within 10 min in the presence of readily available oxidants and trimethylsilyl azide. Selective substitution of the formed α-amino azide by carbon nucleophiles (electron-rich aromatic, malonate, organosilicon, organoboron, organozinc, and organomagnesium compounds) was then achieved in a one-pot fashion, leading to the formation of 1,2-, 1,3-, and 1,4-diamines with the amino groups protected orthogonally as an amide/carbamate and an azide.
- Nguyen, Tin V. T.,Wang, Ming-Ming,Waser, Jerome
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supporting information
p. 11969 - 11975
(2021/08/24)
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- Photocatalyzed Triplet Sensitization of Oximes Using Visible Light Provides a Route to Nonclassical Beckmann Rearrangement Products
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Oximes are valuable synthetic intermediates for the preparation of a variety of functional groups. To date, the stereoselective synthesis of oximes remains a major challenge, as most current synthetic methods either provide mixtures of E and Z isomers or furnish the thermodynamically preferred E isomer. Herein we report a mild and general method to achieve Z isomers of aryl oximes by photoisomerization of oximes via visible-light-mediated energy transfer (EnT) catalysis. Facile access to (Z)-oximes provides opportunities to achieve regio- and chemoselectivity complementary to those of widely used transformations employing oxime starting materials. We show an enhanced one-pot protocol for photocatalyzed oxime isomerization and subsequent Beckmann rearrangement that enables novel reactivity with alkyl groups migrating preferentially over aryl groups, reversing the regioselectivity of the traditional Beckmann reaction. Chemodivergent N- or O- cyclizations of alkenyl oximes are also demonstrated, leading to nitrones or cyclic oxime ethers, respectively.
- Zhang, Xiao,Rovis, Tomislav
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supporting information
p. 21211 - 21217
(2021/12/27)
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- Synthesis of 1,4-Dihydropyridines and Related Heterocycles by Iodine-Mediated Annulation Reactions of N-Cyclopropyl Enamines
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The annulation of N-cyclopropyl enamines to produce 1,4-dihydropyridine (1,4-DHP) derivatives is described. In the presence of molecular iodine (I2), an N-cyclopropyl enamine substrate undergoes iodination, opening of the cyclopropyl ring, and
- Chang, Junbiao,Fang, Yingchao,Wang, Manman,Wei, Lanlan,Xia, Biao,Yu, Wenquan,Zhao, Yifei,Zhao, Zongxiang
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p. 9625 - 9630
(2021/12/14)
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- NaOTs-promoted transition metal-free C-N bond cleavage to form C-X (X = N, O, S) bonds
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Multifunctional transformation of amide C-N bond cleavage is reported. The protocol applies to benzamide, thioamide, alcohols, and mercaptan under similar reaction conditions catalyzed by NaOTs. It is noteworthy that NaOTs can not only be recycled and reused for up to three cycles without significant loss in catalytic activity, but also catalyze gram-grade reactions. This study provides a novel solution with mild conditions and a simple procedure for transformation of multiple amides.
- Chen, Wei,Liu, Sicheng,Liu, Tingting,Majeed, Irfan,Ye, Xiaojing,Zeng, Zhuo,Zhang, Yuqi,Zhu, Yulin
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supporting information
p. 8566 - 8571
(2021/10/20)
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- UV-Light-Induced N-Acylation of Amines with α-Diketones
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Herein, we develop a mild method for N-acylation of primary and secondary amines with α-diketones induced by ultraviolet (UV) light. Forty-six examples with various functional groups are explored at room temperature with irradiation by three 26 W UV lamps (350-380 nm). The yield reaches 97%. The gram scale experiment product yield is 76%. Moreover, this system can be applied to the synthesis of several amino acid derivatives. Mechanistic studies show that benzoin is generated in situ from benzil under UV irradiation.
- Xu, Zhihui,Yang, Tianbao,Tang, Niu,Ou, Yifeng,Yin, Shuang-Feng,Kambe, Nobuaki,Qiu, Renhua
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supporting information
p. 5329 - 5333
(2021/07/21)
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- Nickel-Catalyzed Photodehalogenation of Aryl Bromides
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Herein, we describe a Ni-catalyzed photodehalogenation of aryl bromides under visible-light irradiation that utilizes tetrahydrofuran as hydrogen source. The protocol obviates the need for exogeneous amine reductants or photocatalysts and is characterized by its simplicity and broad scope, including challenging substrate combinations.
- Higginson, Bradley,Sanjosé-Orduna, Jesus,Gu, Yiting,Martin, Ruben
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supporting information
p. 1633 - 1636
(2021/04/23)
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- Benzyne-Mediated Esterification Reaction
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A benzyne-mediated esterification of carboxylic acids and alcohols under mild conditions has been realized, which is made possible via a selective nucleophilic addition of carboxylic acid to benzyne in the presence of alcohol. After a subsequent transesterification with alcohol, the corresponding esters can be produced efficiently. This benzyne-mediated protocol can be used on the modification of Ibuprofen, cholesterol, estradiol, and synthesis of nandrolone phenylpropionate. In addition, benzyne can also be used to promote lactonization and amidation reaction.
- Zhao, Jinlong,Shi, Jiarong,Li, Yang
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supporting information
p. 7274 - 7278
(2021/10/01)
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- Oxidative Fluorination of Cyclopropylamides through Organic Photoredox Catalysis
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We report an oxidative ring-opening strategy to transform cyclopropylamides and cyclobutylamides into fluorinated imines. The imines can be isolated in their more stable hemiaminal form, with the fluorine atom installed selectively at the γ or δ position. Both inexpensive benzophenone with UVA light or organic and inorganic dyes with blue light could be used as photoredox catalysts to promote this process. Various fluorinated amines were then obtained by nucleophilic attack on the hemiaminals in one pot, giving access to a broad range of useful building blocks for medicinal chemistry.
- Wang, Ming-Ming,Waser, Jér?me
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supporting information
p. 16420 - 16424
(2020/07/30)
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- Pyridine-Enabled C-N Bond Activation for the Rapid Construction of Amides and 4-Pyridylglyoxamides by Cooperative Palladium/Copper Catalysis
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A pyridine-enabled C-N bond activation of peptidomimetics employing cooperative palladium/copper catalysis in water is developed. Diverse amides and 4-pyridylglyoxamides are simultaneously synthesized through two steps from commercially available materials in a rapid, environmentally friendly, and high atom-economical manner.
- Song, Liangliang,Claessen, Sander,Van Der Eycken, Erik V.
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p. 8045 - 8054
(2020/07/15)
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- Graphene oxide: A convenient metal-free carbocatalyst for facilitating amidation of esters with amines
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Herein, we report a graphene oxide (GO) catalyzed condensation of non-activated esters and amines, that can enable diverse amides to be synthesized from abundant ethyl esters forming only volatile alcohol as a by-product. GO accelerates ester to amide conversion in the absence of any additives, unlike other catalysts. A wide range of ester and amine substrates are screened to yield the respective amides in good to excellent yields. The improved catalytic activity can be ascribed to the oxygenated functionalities present on the graphene oxide surface which forms H-bonding with the reactants accelerating the reaction. Improved yields and a wide range of functional group tolerance are some of the important features of the developed protocol.
- Patel, Khushbu P.,Gayakwad, Eknath M.,Shankarling, Ganapati S.
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p. 2661 - 2668
(2020/02/20)
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- Chemoselective Synthesis of α-Amino-α-cyanophosphonates by Reductive Gem-Cyanation-Phosphonylation of Secondary Amides
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A novel approach to α-amino-α-cyanophosphonates has been developed. The method features a Tf2O-mediated reductive geminal cyanation/phosphonylation of secondary amides. Mild reaction conditions, high bond-forming efficiency, inexpensive readily available starting materials, and good to excellent yields with wide functional group compatibility constitute the main advantages of this method. The protocol can be run on a gram scale.
- Chen, Ting-Ting,Wang, Ai-E,Huang, Pei-Qiang
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supporting information
p. 3808 - 3812
(2019/05/24)
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- Tert -Butyl nitrite promoted transamidation of secondary amides under metal and catalyst free conditions
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A mild and efficient method is demonstrated for the transamidation of secondary amides with various amines including primary, secondary, cyclic and acyclic amines in the presence of tert-butyl nitrite. The reaction proceeds through the N-nitrosamide intermediate and provides the transamidation products in good to excellent yields at room temperature. Moreover, the developed methodology does not require any catalyst or additives.
- Sureshbabu, Popuri,Azeez, Sadaf,Chaudhary, Priyanka,Kandasamy, Jeyakumar
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supporting information
p. 845 - 850
(2019/01/30)
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- Vanadium-Catalyzed Oxidative C(CO)-C(CO) Bond Cleavage for C-N Bond Formation: One-Pot Domino Transformation of 1,2-Diketones and Amidines into Imides and Amides
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A novel vanadium-catalyzed one-pot domino reaction of 1,2-diketones with amidines has been identified that enables their transformation into imides and amides. The reaction proceeds by dual acylation of amidines via oxidative C(CO)-C(CO) bond cleavage of 1,2-diketones to afford N,N′-diaroyl-N-arylbenzamidine intermediates. In the reaction, these intermediates are easily hydrolyzed into imides and amides through vanadium catalysis. This method provides a practical, simple, and mild synthetic approach to access a variety of imides as well as amides in high yields. Moreover, one-step construction of imide and amide bonds with a long-chain alkyl group is an attractive feature of this protocol.
- Digwal, Chander Singh,Yadav, Upasana,Ramya, P. V. Sri,Sana, Sravani,Swain, Baijayantimala,Kamal, Ahmed
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p. 7332 - 7345
(2017/07/26)
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- A study on reactions of an alkynylsilane with oxone-KX (X = Cl, Br, I) and its one-pot transformation into an amide/ester
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Oxyhalogenation reactions of a variety of alkynylsilanes were studied using oxone as mild oxidant and KCl, KBr, and KI as halogen sources. In this study, reaction of an alkynylsilane with oxone-KX (X = Cl or Br) produced trichloromethyl/tribromomethyl ketones inhigh yields. Under similar conditions, however, reactions of alkynylsilanes with oxone-KI were found to give exclusively 1,2,2-triiodovinyl derivatives in high yields. In this study, new methods were deveoped for effcient one-pot tranformation of alkynylsilanes into amides and esters by reaction with amines and alcohols respectively via trihalomethyl ketone.
- Sriramoju, Vinodkumar,Jillella, Raveendra,Kurva, Srinivas,Madabhushi, Sridhar
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p. 560 - 562
(2017/03/30)
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- Copper-Manganese Spinel Oxide Catalyzed Synthesis of Amides and Azobenzenes via Aminyl Radical Cations
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A highly efficient Cu-Mn-catalyzed process for the aminolysis of esters was developed. Also, the catalyst promoted the self- And cross-dehydrogenative coupling of anilines to generate symmetrical and unsymmetrical azobenzenes, respectively. The reactions were performed under neutral conditions with an inexpensive catalyst, gave high yields, and offered wide functional group tolerance. Spinel tap: A novel facet of aminyl radical cation reactivity with esters for the synthesis of amides is presented. The developed method also gives access to symmetrical and unsymmetrical azobenzenes. The reactions are performed under neutral conditions with an inexpensive catalyst, give high yields, and have a wide functional group tolerance.
- Sultan, Shaista,Kumar, Manjeet,Devari, Shekaraiah,Mukherjee, Debaraj,Ali Shah, Bhahwal
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p. 703 - 707
(2016/03/05)
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- Highly efficient dehydrogenative cross-coupling of aldehydes with amines and alcohols
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A common protocol for the synthesis of amides, esters and α-ketoesters via cross dehydrogenative coupling of aldehydes and amines/alcohols has been developed. The method is applicable to a wide variety of alcohols and amines as well as aliphatic and aromatic aldehydes. Also, the use of acetaldehyde for acetylation and ethyl glyoxalate to access 2-oxo-amino esters is presented for the first time.
- Deshidi, Ramesh,Rizvi, Masood Ahmad,Shah, Bhahwal Ali
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p. 90521 - 90524
(2015/11/11)
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- An attractive route to transamidation catalysis: Facile synthesis of new o-aryloxide-N-heterocyclic carbene ruthenium(II) complexes containing trans triphenylphosphine donors
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Well-defined robust ruthenium(II) complexes 3a-d bearing o-aryloxide-N-heterocyclic carbene ligands with different wingtip substituents (3a (R = Me), 3b (R = Ph), 3c (R = iPr) and 3d (R = Mes)) in the imidazole ring were synthesized in good yields by the reaction of imidazolium proligands with metal precursor [RuHCl(CO)(PPh3)3] by transmetallation from the corresponding silver carbene complexes. All the Ru(II)-NHC complexes have been characterized by elemental analyses, spectroscopic methods as well as ESI mass spectrometry. The molecular structure of the complex 3a was identified by means of single-crystal X-ray diffraction analysis, which revealed that the complexes possess a distorted octahedral geometry. In order to explore the catalytic potential of the synthesized complexes, all the four [Ru-NHC] complexes [3a-d] were tested as catalysts for transamidation of carboxamides with amines. Notably, the complex 3a was found to be very efficient and versatile catalyst toward transamidation of a wide range of amides with amines.
- Nirmala, Muthukumaran,Prakash, Govindan,Viswanathamurthi, Periasamy,Malecki, Jan Grzegorz
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- Hypervalent iodine catalyzed transamidation of carboxamides with amines
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This protocol describes the catalytic use of diacetoxyiodobenzene (DIB) for the efficient transamidation of carboxamides with amines under mild conditions.
- Vanjari, Rajeshwer,Kumar Allam, Bharat,Nand Singh, Krishna
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p. 1691 - 1694
(2013/03/28)
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- Selective formation of secondary amides via the copper-catalyzed cross-coupling of alkylboronic acids with primary amides
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For the first time, a general catalytic procedure for the cross-coupling of primary amides and alkylboronic acids is demonstrated. The key to the success of this reaction was the identification of a mild base (NaOSiMe3) and oxidant (di-tert-butyl peroxide) to promote the copper-catalyzed reaction in high yield. This transformation provides a facile, high-yielding method for the monoalkylation of amides.
- Rossi, Steven A.,Shimkin, Kirk W.,Xu, Qun,Mori-Quiroz, Luis M.,Watson, Donald A.
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supporting information
p. 2314 - 2317
(2013/06/05)
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- Transition metal-free one-pot synthesis of 2-substituted 3-carboxy-4-quinolone and chromone derivatives
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A novel one-pot synthesis of the 2-substituted 3-carboxy-4-quinolone/ chromone derivatives from readily available 3-oxo-3-arylpropanoates and amides/acyl chlorides is reported, without any transition metal aid. The Royal Society of Chemistry 2013.
- Lin, Jian-Ping,Long, Ya-Qiu
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supporting information
p. 5313 - 5315
(2013/06/27)
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- Amidation of aldehydes and alcohols through α-iminonitriles and a sequential oxidative three-component strecker reaction/thio-michael addition/alumina-promoted hydrolysis process to access β-mercaptoamides from aldehydes, amines, and thiols
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Mild and general alumina-promoted hydrolysis conditions for converting α-iminonitriles into carboxamides have been developed. In combination with the oxidative three-component Strecker reaction, the one-pot direct amidation of aldehydes and alcohols is reported. Subsequently, an Yb(OTf) 3-catalyzed Michael addition of thiols to α,β-unsaturated α-iminonitriles is reported for the synthesis of β-mercapto-α- iminonitriles. The successful integration of an oxidative Strecker reaction, thio-Michael addition, and neutral-alumina-promoted hydrolysis of β-mercapto-α-iminonitriles into a three-component one-pot process allowed us to develop the direct conversion of amines, aldehydes, and thiols into β-mercaptoamides. All of these procedures were applicable to aromatic and aliphatic amines and aldehydes. First direct: The direct amidation reactions of aldehydes and alcohols were performed in combination with the oxidative three-component synthesis of α-iminonitriles. In addition, β-mercaptoamides were readily accessed from α,β-unsaturated aldehydes, amines, and thiols by a sequential process that involved a three-component Strecker reaction, Yb(OTf)3-catalyzed thio-Michael addition, and hydrolysis of the resulting β-mercapto-α-iminonitriles (see scheme). Copyright
- Gualtierotti, Jean-Baptiste,Schumacher, Xavier,Fontaine, Patrice,Masson, Géraldine,Wang, Qian,Zhu, Jieping
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p. 14812 - 14819
(2013/01/15)
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- Electrochemical cleavage of sulfonamides: An efficient and tunable strategy to prevent β-fragmentation and epimerization
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The electrochemical reduction of sensitive sulfonamides is described. The addition of a benzoyl group on the nitrogen atom facilitates the reductive cleavage of sulfonamides preventing β-fragmentation and epimerization. This strategy was successfully applied to the cyclopropylamine and to α-amino stannanes.
- Viaud, Pierre,Coeffard, Vincent,Thobie-Gautier, Christine,Beaudet, Isabelle,Galland, Nicolas,Quintard, Jean-Paul,Le Grognec, Erwan
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p. 942 - 945
(2012/03/26)
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- Mo(CO)6-mediated carbamoylation of aryl halides
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A simple method for the synthesis of amides has been developed by molybdenum-mediated carbamoylation of aryl halides. Whereas the conventional palladium-catalyzed three-component coupling reaction requires a large excess of gaseous carbon monoxide, the incorporation of carbon monoxide in this Mo-mediated carbamoylation reaction is so efficient that it requires only a slight excess amount of carbon monoxide in the form of its molybdenum complex, Mo(CO)6. The reaction is applicable for the synthesis of a wide variety of not only secondary and tertiary amides but also primary amides by using aqueous ammonia.
- Ren, Wei,Yamane, Motoki
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experimental part
p. 8410 - 8415
(2011/02/23)
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- N-cyclopropylation of indoles and cyclic amides with copper(II) reagent
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Copper-mediated coupling reactions of cyclopropylboronic acid with indoles and cyclic amides are described. The process utilizes catalytic or stoichiometric amounts of copper(ll) acetate, DMAP, and NaHMDS at 95 °C under an atmosphere containing oxygen. A variety of functional groups remain intact throughout the reaction.
- Tsuritani, Takayuki,Strotman, Neil A.,Yamamoto, Yuhei,Kawasaki, Masashi,Yasuda, Nobuyoshi,Mase, Toshiaki
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supporting information; experimental part
p. 1653 - 1655
(2009/04/07)
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- Organophosphorus esters of 1-hydroxy-2-phenylbenzimidazole: Synthesis and utilization as novel peptide coupling reagents
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Highly efficient coupling reagents - phosphoric acid diethyl ester 2-phenylbenzimidazol-1-yl ester, diphenylphosphinic acid 2-phenylbenzimidazol-1- yl ester and phosphoric acid diphenyl ester 2-phenylbenzimidazol-1-yl ester - were designed, synthesized and successfully applied in peptide coupling reactions. Their efficiency was evaluated through the synthesis of a range of amides and peptides, and the extent of racemization was studied by HPLC and found to be negligible. The mechanism of action is probably similar to those found for organophoshorus esters of hydroxybenzotriazole: a presumption supported by the isolation and characterization by mass spectrometry and 1H NMR of some of the proposed intermediates. Georg Thieme Verlag Stuttgart.
- Kokare, Nagnnath D.,Nagawade, Rahul R.,Rane, Vipul P.,Shinde, Devanand B.
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p. 766 - 772
(2008/01/04)
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- Oxidation of tertiary benzamides by 5,10,15,20-tetraphenyl- porphyrinatoironIII chloride-tert-butylhydroperoxide
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Tertiary benzamides are oxidized by the 5,10,15,20- tetraphenylporphyrinatoiron(III) chloride-ButOOH system at the α-position of the N-alkyl groups. The major products are N-acylamides, although small amounts of secondary amides, the products of dealkylation, are also formed. Plots of initial rate versus initial substrate concentration for these reactions are curved, suggesting formation of an oxidant-substrate complex. The reaction rates are almost insensitive to the substituent in the benzamide moiety, but there is a kinetic deuterium isotope effect of 5.6 for the reaction of the N,N-(CH3)2 and N,N-(CD3) 2 compounds. Comparison of the reaction products from N-alkyl-N-methylbenzamides reveals that, for all compounds studied except N-cyclopropyl-N-methylbenzamide, oxidation of the alkyl group is preferred, strongly so (by a factor of ca. 8) for N-allyl-N-methylbenzamide. In contrast to microsomal oxidation, there is no steric hindrance to oxidation of an isopropyl group. Thus, we propose that these reactions proceed via hydrogen atom abstraction to form an α-carbon-centred radical and we attribute the observed diminished reactivity of the N-cyclopropyl group to its known reluctance to form a cyclopropyl radical. Oxidation of N-methyl-N-(2,2,3,3- tetramethylcyclopropyl)methylbenzamide provides preliminary evidence for rearrangement of an intermediate radical. While it remains unclear how these reactions proceed directly to the N-acyl products, we have established that N-hydroxymethyl, N-alkoxymethyl and N-alkylperoxymethyl intermediates are not involved.
- Constantino, Luis,Iley, Jim
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p. 1894 - 1900
(2007/10/03)
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- 11-BETA-HYDROXYSTEROID DEHYDROGENASE 1 INHIBITORS USEFUL FOR THE TREATMENT OF DIABETES, OBESITY AND DYSLIPIDEMIA
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Compounds having Formula (I), including pharmaceutically acceptable salts, hydrates and solvates thereof, are selective inhibitors of the 11β-HSD1 enzyme. The compounds are useful for the treatment of diabetes, such as noninsulin-dependent diabetes (NIDDM), hyperglycemia, obesity, insulin resistance, dylsipidemia, hyperlipidemia, hypertension, Syndrome X, and other symptoms associated with NIDDM.
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- POTENTIAL CENTRAL NERVOUS SYSTEM ACTIVE AGENTS. 3. SYNTHESIS OF SOME SUBSTITUTED BENZAMIDES AND PHENYLACETAMIDES.
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The preparation and special properties (IR, **1H NMR) are given for 45 benzamides and 10 phenylacetamides substituted on nitrogen with allyl, benzhydryl, benzyl, or cyclopropyl groups, and variously substituted on the acyl part with halo, methoxyl, methyl, or nitro groups. The benzamide derivatives were synthesized by the Schotten-Baumann method, and the phenylacetamide derivatives were prepared by heating the appropriate N-benzhydrylammonium salt in o-xylene. Thirty-one of the compounds are new.
- Agwada
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p. 231 - 235
(2007/10/02)
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