- Reductive ipso-radical cyclization onto aromatic rings of five-membered alicyclic amino acids bearing N-(2-phenyl)benzoyl groups by photoinduced electron transfer promoted decarboxylation
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A new radical cyclization has been developed for the one-step synthesis of spiro dihydroisoquinolinone derivatives from alicyclic amino acids bearing N-(2-phenyl)benzoyl groups through photoinduced electron transfer (PET)-promoted decarboxylation. Reductive ipso-radical cyclization onto a benzene ring by an alkyl radical is achieved under mild conditions for the first time, although the substrates are limited to five-membered aliphatic carboxylic acids bearing N-(2-phenyl)benzoyl groups.
- Yamada, Tomoaki,Ozaki, Yui,Yamawaki, Mugen,Sugiura, Yoshihiko,Nishino, Kana,Morita, Toshio,Yoshimi, Yasuharu
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Read Online
- Photoenzymatic Reductions Enabled by Direct Excitation of Flavin-Dependent "Ene"-Reductases
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Non-natural photoenzymatic reactions reported to date have depended on the excitation of electron donor-acceptor complexes formed between substrates and cofactors within protein active sites to facilitate electron transfer. While this mechanism has unlocked new reactivity, it limits the types of substrates that can be involved in this area of catalysis. Here we demonstrate that direct excitation of flavin hydroquinone within "ene"-reductase active sites enables new substrates to participate in photoenzymatic reactions. We found that by using photoexcitation these enzymes gain the ability to reduce acrylamides through a single electron transfer mechanism.
- Sandoval, Braddock A.,Clayman, Phillip D.,Oblinsky, Daniel G.,Oh, Seokjoon,Nakano, Yuji,Bird, Matthew,Scholes, Gregory D.,Hyster, Todd K.
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supporting information
p. 1735 - 1739
(2021/01/25)
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- Erratum: Photoenzymatic Reductions Enabled by Direct Excitation of Flavin-Dependent 'Ene'-Reductases (J. Am. Chem. Soc. (2021) 143:4 (1735-1739) DOI: 10.1021/jacs.0c11494)
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Support by the Department of Energy was inadvertently left out of the Acknowledgments and a coauthor's name was misspelled in the Supporting Information. The scientific part of the manuscript remains unchanged. The complete correct Acknowledgment paragraph is as follows.
- Sandoval, Braddock A.,Clayman, Phillip D.,Oblinsky, Daniel G.,Oh, Seokjoon,Nakano, Yuji,Bird, Matthew,Scholes, Gregory D.,Hyster, Todd K.
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supporting information
p. 3662 - 3662
(2021/04/09)
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- Metal-free approach for hindered amide-bond formation with hypervalent iodine(iii) reagents: application to hindered peptide synthesis
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A new bio-inspired approach is reported for amide and peptide synthesis using α-amino esters that possess a potential activating group (PAG) at the ester residue. To activate the ester functionality under mild metal-free conditions, we exploited the facile dearomatization of phenols with hypervalent iodine(iii) reagents. Using a pyridine-hydrogen fluoride complex, highly reactive acyl fluoride intermediates can be successfully generated, thereby allowing for the smooth formation of sterically hindered amides and peptides from bulky amines and α-amino esters, respectively.
- Lee, Hyo-Jun,Huang, Xiao,Sakaki, Shigeyoshi,Maruoka, Keiji
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supporting information
p. 848 - 855
(2021/02/09)
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- Efficiency Enhancement of a Photocatalytic Decarbonylation of an Aminocyclopropenone by Benzothiophene Substitution
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To improve the efficiency of the photocatalytic decarbonylation of cyclopropenones, the effects of substituents on cyclopropenone were explored. A benzothiophene-substituted aminocyclopropenone exhibited significantly improved decarbonylation efficiency t
- Mishiro, Kenji,Nomura, Mitsuki,Furuyama, Taniyuki,Kunishima, Munetaka
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p. 3625 - 3636
(2021/03/03)
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- Method for preparing amide compound by photocatalysis of nitrogen-containing heterocyclic compound
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The invention provides a method for preparing an amide compound by photocatalysis of a nitrogen-containing heterocyclic compound. The method comprises the following steps: mixing the nitrogen-containing heterocyclic compound, organic carboxylic acid and tetrahalomethane in a solvent, adding a catalyst, and reacting under the illumination condition to prepare the amide compound. According to the invention, the organic carboxylic acid, the nitrogen-containing heterocyclic compound containing reactive hydrogen on nitrogen atoms and the tetrahalomethane are used as raw materials, so the raw materials are wide in source, low in cost and high in safety, and large-scale production is facilitated; the halogen simple substance is co-produced in the reaction process, the added value is high, a large amount of waste is prevented from being generated, and the method has high atom economy and environmental friendliness; light conditions are adopted to replace traditional heating and high-pressure conditions, the reaction conditions are mild, environmental pollution is reduced, and the reaction cost is reduced; the method has the advantages of good substrate applicability, mild process conditions, environmental protection, simple process, simple and feasible operation method, and facilitation of popularization and application.
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Paragraph 0047-0050; 0093; 0094
(2021/06/06)
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- Efficient cleavage of tertiary amide bonds: Via radical-polar crossover using a copper(ii) bromide/Selectfluor hybrid system
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A novel approach for the efficient cleavage of the amide bonds in tertiary amides is reported. Based on the selective radical abstraction of a benzylic hydrogen atom by a CuBr2/Selectfluor hybrid system followed by a selective cleavage of an N-C bond, an acyl fluoride intermediate is formed. This intermediate may then be derivatized in a one-pot fashion. The reaction proceeds under mild conditions and exhibits a broad substrate scope with respect to the tertiary amide moiety as well as to nitrogen, oxygen, and carbon nucleophiles for the subsequent derivatization. Mechanistic studies suggest that the present reaction proceeds via a radical-polar crossover process that involves benzylic carbon radicals generated by the selective radical abstraction of a benzylic hydrogen atom by the CuBr2/Selectfluor hybrid system. Furthermore, a synthetic application of this method for the selective cleavage of peptides is described. This journal is
- Maruoka, Keiji,Matsumoto, Akira,Wang, Zhe
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p. 12323 - 12328
(2020/12/08)
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- N-Hydroxybenzimidazole as a structurally modifiable platform forN-oxyl radicals for direct C-H functionalization reactions
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Methods for direct functionalization of C-H bonds mediated byN-oxyl radicals constitute a powerful tool in modern organic synthesis. While severalN-oxyl radicals have been developed to date, the lack of structural diversity for these species has hampered further progress in this field. Here we designed a novel class ofN-oxyl radicals based onN-hydroxybenzimidazole, and applied them to the direct C-H functionalization reactions. The flexibly modifiable features of these structures enabled facile tuning of their catalytic performance. Moreover, with these organoradicals, we have developed a metal-free approach for the synthesis of acyl fluoridesviadirect C-H fluorination of aldehydes under mild conditions.
- Hatanaka, Miho,Jiang, Julong,Maruoka, Keiji,Matsumoto, Akira,Sakamoto, Ryu,Sakurai, Shunya,Tsuzuki, Saori,Yoshii, Tomomi
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p. 5772 - 5778
(2020/06/22)
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- Environmentally benign decarboxylative: N-, O-, and S-Acetylations and acylations
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An operationally simple and general method for acetylation and acylation of a wide variety of substrates (amines, alcohols, phenols, thiols, and hydrazones) has been reported. Meldrum's acid and its derivatives have been used as an air-stable, non-volatile, cost-effective, and easy to handle acetylating/acylating agent. Easily separable byproducts (CO2 and acetone) allowed the isolation of analytically pure acetylated products without the requirement of work-up and any chromatography. This journal is
- Ghosh, Santanu,Purkait, Anisha,Jana, Chandan K.
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supporting information
p. 8721 - 8727
(2020/12/30)
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- C-C Bond Cleavage of Unactivated 2-Acylimidazoles
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2-Acylimidazoles are widely used as post-Transformable carboxylic acid equivalents in chemoselective and enantioselective reactions. Their transformations, however, require pretreatment with highly reactive, toxic methylating reagents to facilitate C-C bond cleavage. Here, we demonstrate that such pretreatment can be avoided and the C-C bond cleaved under neutral conditions without the use of additional reagents or catalysts. The scope of the reaction, including the use of products reported in the literature as substrates, and some mechanistic insights are described.
- Xin, Hai-Long,Pang, Bo,Choi, Jeesoo,Akkad, Walaa,Morimoto, Hiroyuki,Ohshima, Takashi
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p. 11592 - 11606
(2020/10/23)
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- Phototriggered Active Alkyne Generation from Cyclopropenones with Visible Light-Responsive Photocatalysts
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A photocatalytic active alkyne generation reaction was developed using cyclopropenone as a starting reagent. Visible light-responsive photocatalysts induced cyclopropenone decarbonylation. The resulting highly reactive alkyne could be used directly, witho
- Mishiro, Kenji,Kimura, Takeshi,Furuyama, Taniyuki,Kunishima, Munetaka
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supporting information
p. 4101 - 4105
(2019/06/17)
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- Unified Approach to the Chemoselective α-Functionalization of Amides with Heteroatom Nucleophiles
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Functionalization at the α-position of carbonyl compounds has classically relied on enolate chemistry. As a result, the generation of a new C-X bond, where X is more electronegative than carbon requires an oxidation event. Herein we show that, by rendering the α-position of amides electrophilic through a mild and chemoselective umpolung transformation, a broad range of widely available oxygen, nitrogen, sulfur, and halogen nucleophiles can be used to generate α-functionalized amides. More than 60 examples are presented to establish the generality of this process, and calculations of the mechanistic aspects underline a fragmentation pathway that accounts for the broadness of this methodology.
- Gon?alves, Carlos R.,Lemmerer, Miran,Teskey, Christopher J.,Adler, Pauline,Kaiser, Daniel,Maryasin, Boris,González, Leticia,Maulide, Nuno
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supporting information
p. 18437 - 18443
(2019/11/21)
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- Formamide catalyzed activation of carboxylic acids-versatile and cost-efficient amidation and esterification
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A novel, broadly applicable method for amide C-N and ester C-O bond formation is presented based on formylpyrrolidine (FPyr) as a Lewis base catalyst. Herein, trichlorotriazine (TCT), which is the most cost-efficient reagent for OH-group activation, was employed in amounts of ≤40 mol% with respect to the starting material (100 mol%). The new approach is distinguished by excellent cost-efficiency, waste-balance (E-factor down to 3) and scalability (up to >80 g). Moreover, high levels of functional group compatibility, which includes acid-labile acetals and silyl ethers, are demonstrated and even peptide C-N bonds can be formed. In comparison to reported amidation procedures using TCT, yields are considerably improved (for instance from 26 to 91%) and esterification is facilitated for the first time in synthetically useful yields. These significant enhancements are rationalized by activation by means of acid chlorides instead of less electrophilic acid anhydride intermediates.
- Huy, Peter H.,Mbouhom, Christelle
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p. 7399 - 7406
(2019/08/20)
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- Broadly Applicable Ytterbium-Catalyzed Esterification, Hydrolysis, and Amidation of Imides
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An efficient, broadly applicable, operationally simple, and divergent process for the transformation of imides into a range of carboxylic acid derivatives under mild conditions is reported. By simply using catalytic amounts of ytterbium(III) triflate as a Lewis acid promoter in the presence of alcohols, water, amines, or N,O-dimethylhydroxylamine, a broad range of imides is smoothly and readily converted to the corresponding esters, carboxylic acids, amides, and Weinreb amides in good yields. This method notably enables an easy cleavage of oxazolidinone-based auxiliaries.
- Guissart, Céline,Barros, Andre,Rosa Barata, Luis,Evano, Gwilherm
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supporting information
p. 5098 - 5102
(2018/09/13)
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- Chemoselective amide reductions by heteroleptic fluoroaryl boron Lewis acids
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The heteroleptic borane catalyst (C6F5)2B(CH2CH2CH2)BPin is found to hydrosilylatively reduce amides under mild conditions. Simple tertiary amides can be reduced using Me2EtSiH, whereas tertiary benzamides required a more reactive secondary silane, Et2SiH2, for efficient reduction. The catalytic system described exhibits exceptional chemoselectivity in the reduction of oligoamides and tolerates functionalities which are prone to reduction under similar conditions.
- Peruzzi, Michael T.,Mei, Qiong Qiong,Lee, Stephen J.,Gagné, Michel R.
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supporting information
p. 5855 - 5858
(2018/06/13)
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- Phototriggered Dehydration Condensation Using an Aminocyclopropenone
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A phototriggered dehydration condensation using an aminocyclopropenone has been developed. The UV irradiation of an aminocyclopropenone generated a highly reactive ynamine in situ and the dehydration condensation of a carboxylic acid and an amine coexisting in the reaction solution smoothly proceeded to afford an amide. This reaction is completely controllable by the ON/OFF states of a UV lamp.
- Mishiro, Kenji,Yushima, Yuki,Kunishima, Munetaka
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supporting information
p. 4912 - 4915
(2017/09/23)
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- Palladium-catalyzed highly regioselective hydroaminocarbonylation of aromatic alkenes to branched amides
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Pd(t-Bu3P)2 has been successfully identified as an efficient catalyst for the hydroaminocarbonylation of aromatic alkenes to branched amides under relatively mild reaction conditions. With hydroxylamine hydrochloride as an additive,
- Zhu, Jinping,Gao, Bao,Huang, Hanmin
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supporting information
p. 2910 - 2913
(2017/04/11)
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- Interception of amide ylides with sulfonamides: Synthesis of (: E)- N -sulfonyl amidines catalyzed by Zn(OTf)2
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Through the interception of amide ylides with sulfonamides, we herein report the first general example of an intermolecular condensation reaction between sulfonamides and amides. Beyond formamides, this approach was successfully applied to a variety of lactams and linear amides, giving rise to a broad array of (E)-N-sulfonyl amidines.
- Chen, Jijun,Long, Wenhao,Fang, Shangwen,Yang, Yonggang,Wan, Xiaobing
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supporting information
p. 13256 - 13259
(2017/12/26)
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- General and Mild Cobalt-Catalyzed C-Alkylation of Unactivated Amides and Esters with Alcohols
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The borrowing hydrogen or hydrogen autotransfer methodology is an elegant and sustainable or green concept to construct carbon-carbon bonds. In this concept, alcohols, which can be obtained from barely used and indigestible biomass, such as lignocellulose, are employed as alkylating reagents. An especially challenging alkylation is that of unactivated esters and amides. Only noble metal catalysts based on iridium and ruthenium have been used to accomplish these reactions. Herein, we report on the first base metal-catalyzed α-alkylation of unactivated amides and esters by alcohols. Cobalt complexes stabilized with pincer ligands, recently developed in our laboratory, catalyze these reactions very efficiently. The precatalysts can be synthesized easily from commercially available starting materials on a multigram scale and are self-activating under the basic reaction conditions. This Co catalyst class is also able to mediate alkylation reactions of both esters and amides. In addition, we apply the methodology to synthesize ketones and to convert alcohols into aldehydes elongated by two carbon atoms.
- Deibl, Nicklas,Kempe, Rhett
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supporting information
p. 10786 - 10789
(2016/09/09)
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- Ruthenium-catalyzed direct α-alkylation of amides using alcohols
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The highly efficient direct α-alkylation of unactivated amides has been accomplished using alcohols in the presence of the Ru-PNN catalyst (0.1 mol%) with a high turnover number. Using this approach, 2-oxindole was directly transformed into C3-alkylated 3-hydroxyindolin-2-one in one step without the use of any oxidant.
- Chaudhari, Moreshwar Bhagwan,Bisht, Girish Singh,Kumari, Pooja,Gnanaprakasam, Boopathy
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supporting information
p. 9215 - 9220
(2016/10/13)
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- Chemo- and Stereoselective Transition-Metal-Free Amination of Amides with Azides
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The synthesis of α-amino carbonyl/carboxyl compounds is a contemporary challenge in organic synthesis. Herein, we present a stereoselective α-amination of amides employing simple azides that proceeds under mild conditions with release of nitrogen gas. The
- Tona, Veronica,De La Torre, Aurélien,Padmanaban, Mohan,Ruider, Stefan,González, Leticia,Maulide, Nuno
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supporting information
p. 8348 - 8351
(2016/07/26)
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- Practical Synthesis of Amides via Copper/ABNO-Catalyzed Aerobic Oxidative Coupling of Alcohols and Amines
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A modular Cu/ABNO catalyst system has been identified that enables efficient aerobic oxidative coupling of alcohols and amines to amides. All four permutations of benzylic/aliphatic alcohols and primary/secondary amines are viable in this reaction, enabling broad access to secondary and tertiary amides. The reactions exhibit excellent functional group compatibility and are complete within 30 min-3 h at rt. All components of the catalyst system are commercially available.
- Zultanski, Susan L.,Zhao, Jingyi,Stahl, Shannon S.
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supporting information
p. 6416 - 6419
(2016/06/09)
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- One-Carbon Homologation of Primary Alcohols to Carboxylic Acids, Esters, and Amides via Mitsunobu Reactions with MAC Reagents
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A method is reported for the one-carbon homologation of an alcohol to the extended carboxylic acid, ester, or amide. The process involves the Mitsunobu reaction with an alkoxymalononitrile, followed by unmasking in the presence of a suitable nucleophile. The homologation and unmasking can even be performed in a one-pot process in high yield.
- Kagawa, Natsuko,Nibbs, Antoinette E.,Rawal, Viresh H.
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supporting information
p. 2363 - 2366
(2016/06/09)
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- Rhodium-catalyzed oxidative amidation of allylic alcohols and aldehydes: Effective conversion of amines and anilines into amides
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The rhodium-catalyzed oxidative amidation of allylic alcohols and aldehydes is reported. In situ generated [(BINAP)Rh]BF4 catalyzes the one-pot isomerization/oxidative amidation of allylic alcohols or direct amidation of aldehydes using acetone or styrene as the hydrogen acceptor. The conditions are general, affording good to excellent yields with a wide array of amine and aniline nucleophiles, and chemoselective, other alcohols do not participate in the oxidation reaction. Utilization of biphasic conditions is critical, as they promote an equilibrium between the imine/enamine byproducts and the hemiaminal, which can undergo oxidation to the amide.
- Wu, Zhao,Hull, Kami L.
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p. 969 - 975
(2016/02/05)
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- A two-step, one pot preparation of amines via acyl succinimides. Synthesis of the calcimimetic agents cinacalcet, NPS R-467, and NPS R-568
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Abstract A method has been developed for the preparation of amines through a process of coupling acyl succinimides derived from commercially available carboxylic acids with amines to afford the corresponding amides. These amides are then reduced in situ with either diisobutylaluminum hydride or lithium aluminum hydride. The reaction tandem of the coupling reaction followed by the reduction affords the amine in fair to good yields after purification by flash chromatography. This one-pot, two reaction tandem process has been successfully applied to the synthesis of the calcimimetic agents cinacalcet, NPS R-467, and NPS R-568.
- Gooodman, Cassie A.,Janci, Elise Marie,Onwodi, Olivia,Simpson, Chad C.,Hamaker, Christopher G.,Hitchcock, Shawn R.
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supporting information
p. 4468 - 4471
(2015/06/30)
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- TEMPO-Catalyzed Oxidative Amidation of Alcohols via Hexafluoroisopropyl Esters
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Stepwise oxidative amidation of alcohols using trichloroisocyanuric acid, a catalytic amount of TEMPO in combination with pyridine and hexafluoroisopropyl (HFIP) alcohol followed by amines is described. This procedure used HFIP esters as activating esters which were found to be very efficient acylating agents for amide bond formation. This process is compatible with a number of functional groups and acid-sensitive protecting groups.
- Vatèle, Jean-Michel
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p. 2280 - 2284
(2015/09/28)
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- TMSCN/DBU-mediated facile redox transformation of α,β- unsaturated aldehydes to carboxylic acid derivatives
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Redox transformation of an α,β-unsaturated aldehyde to a carboxylic acid derivative by means of a combination of TMSCN and DBU was investigated. In addition to the wide use of the carboxylic acid derivatives provided by this reaction, temperature-dependent control of the kinetic or thermodynamic protonation pattern was found to selectively switch the stereochemistry of the acyl group in the product.
- Kaise, Hiromi,Shimokawa, Jun,Fukuyama, Tohru
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supporting information
p. 727 - 729
(2014/03/21)
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- Ruthenium-catalysed oxidation of alcohols to amides using a hydrogen acceptor
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A wider investigation into the synthesis of secondary amides from primary alcohols using a hydrogen acceptor using commercially available [Ru(p-cymene)Cl2]2 with bis(diphenylphosphino)butane (dppb) as the catalyst. The report looks at over 50 examples with varying functionality and steric bulk, whilst also covering the first reported results using microwave heating to effect the transformation.
- Watson, Andrew J.A.,Wakeham, Russell J.,Maxwell, Aoife C.,Williams, Jonathan M.J.
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supporting information
p. 3683 - 3690
(2014/05/20)
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- Amides in one pot from Carboxylic Acids and Amines via Sulfinylamides
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An efficient method has been developed for the direct amidification of carboxylic acids via sulfinylamides preformed in situ by the reaction of pure amines with prop-2- ene-1-sulfinyl chloride. The method can be applied to aliphatic acids, including pivalic acid, aromatic acids, and primary and secondary amines. It is compatible with acids bearing unprotected alcohol, phenol, and ketone moieties and applicable to the synthesis of peptides. It does not induce their a-epimerization.
- Bai, Jianfei,Zambron, Bartosz K.,Vogel, Pierre
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supporting information
p. 604 - 607
(2014/04/03)
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- Overcoming product inhibition in catalysis of the intramolecular Schmidt reaction
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A method for carrying out the intramolecular Schmidt reaction of alkyl azides and ketones using a substoichiometric amount of catalyst is reported. Following extensive screening, the use of the strong hydrogen-bond-donating solvent hexafluoro-2-propanol was found to be consistent with low catalyst loadings, which ranged from 2.5 mol % for favorable substrates to 25 mol % for more difficult cases. Reaction optimization, broad substrate scope, and preliminary mechanistic studies of this improved version of the reaction are described.
- Motiwala, Hashim F.,Fehl, Charlie,Li, Sze-Wan,Hirt, Erin,Porubsky, Patrick,Aube, Jeffrey
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p. 9000 - 9009
(2013/07/26)
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- Amide formation in one pot from carboxylic acids and amines via carboxyl and sulfinyl mixed anhydrides
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An efficient method has been developed for the preparation of yet unknown acyclic mixed anhydrides of carboxylic and sulfinic acids. Sterically hindered 2-methylbut-3-ene-2-sulfinyl carboxylates add primary and secondary amines preferentially onto the carbonyl moieties realizing a new method for the one-pot preparation of carboxamides. It uses 1:1 mixtures of carboxylic acids and amines without a base, requires no excess of reagents, and liberates only volatile coproducts. Protected di- and tripeptides have been prepared in solution without epimerization by application of this method.
- Zambron, Bartosz K.,Dubbaka, Srinivas R.,Markovic, Dean,Moreno-Clavijo, Elena,Vogel, Pierre
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supporting information
p. 2550 - 2553
(2013/07/05)
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- Metal-free oxidative amide formation with N-hydroxysuccinimide and hypervalent iodine reagents
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An oxidative amide formation using N-hydroxysuccinimide and hypervalent iodine reagents was developed. The method enables a wide range of aldehydes and amines to be coupled under mild reaction conditions providing amide in good to excellent yield. The radical species in the reaction mixture was observed for the first time using ESR measurement, and along with other mechanistic investigations, a plausible mechanism of the reaction was proposed.
- Yao, Haoyi,Tang, Yun,Yamamoto, Kana
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p. 5094 - 5098
(2012/10/08)
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- Aerobic amide bond formation with N-hydroxysuccinimide
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Breathe easy: Molecular oxygen is one of the most abundant, atom-efficient, and economical oxidants. An aerobic oxidative amide formation from aldehydes and amines is reported. The method uses a catalytic amount of Co(OAc) 2 and N-hydroxysuccinimide as reaction promoters. It is applicable to chiral substrates without loss of their optical purity. Copyright
- Yao, Haoyi,Yamamoto, Kana
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supporting information; experimental part
p. 1542 - 1545
(2012/09/08)
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- Catalytic amide formation with α′-hydroxyenones as acylating reagents
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α′-Hydroxyenones undergo clean, catalytic amidations with amines promoted by the combination of an N-heterocyclic carbene and 1,2,4-triazole. The Royal Society of Chemistry 2009.
- Chiang, Pei-Chen,Kim, Yoonjoo,Bode, Jeffrey W.
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supporting information; experimental part
p. 4566 - 4568
(2010/01/06)
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- Carboxamidation of carboxylic acids with 1-tert-butoxy-2-tert-butoxycarbonyl-1,2-dihydroisoquinoline (BBDI) without bases
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Formation of carboxamides of a variety of carboxylic acids with the coupling reagent BBDI is described. This procedure permits a one pot and simple operation without the need of any bases and no base was?required for even use of amine hydrochlorides. In addition, an approach to BBDI-catalyzed carboxamidation is examined.
- Saito, Yukako,Ouchi, Hidekazu,Takahata, Hiroki
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experimental part
p. 11129 - 11135
(2009/04/11)
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- A novel oxidative transformation of α-aminonitriles to amides
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A novel oxidative transformation of α-aminonitriles to amides is reported. Oxidation of α-aminonitriles with peracid, followed by basic treatment affords, amides in good yields. A mechanistic aspect of this transformation is also discussed.
- Yokoshima, Satoshi,Kubo, Tetsuji,Tokuyama, Hidetoshi,Fukuyama, Tohru
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p. 122 - 123
(2007/10/03)
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- Atropisomeric amides: Stereoselective enolate chemistry and enantioselective synthesis via a new SmI2-mediated reduction
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The use of certain types of atropisomeric amides, incorporating an N-MEM-ortho-tert-bityariume group, for stereoselective reactions, has been explored. Enolate reactions of these systems are highly diastereocontrolled, and enantiomerically enriched starting materials can be obtained, starting from lactic acid, via a new SmI2 mediated reduction process.
- Hughes, Adam D.,Price, David A.,Simpkins, Nigel S.
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p. 1295 - 1304
(2007/10/03)
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- SmI2-mediated reduction of α-functionalised amides: Highly enantiospecific access to an atropisomeric amide
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SmI2 or SmI2-LiCl mixtures can be used to reduce α-functionalised amides in yields of up to 85% depending upon the amide structure. The method has been applied to the synthesis of an atropisomeric anilide system in highly enantioenriched form, starting with (S)-O-acetyl lactic acid.
- Hughes, Adam D.,Simpkins, Nigel S.
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p. 967 - 968
(2007/10/03)
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- THE CONVERSION OF CARBOXYLIC ACIDS TO AMIDES VIA TIN(II) REAGENTS
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Unsymmetrical tin(II) amides can be generated, in situ, by adding one equivalent of an amine to bis(bistrimethylamino) tin, Sn2.Treatment of carboxylic acids with these tin(II) reagents derived from alkyl or aryl amines results in smooth conversion to the corresponding N-alkyl or N-aryl amides.
- Burnell-Curty, Cynthia,Roskamp, Eric J.
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p. 5193 - 5196
(2007/10/02)
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