- Cobalt catalysed aminocarbonylation of thiols in batch and flow for the preparation of amides
-
The synthesis of amides from thiols through a cobalt-catalyzed aminocarbonylation is shown. After optimizing all the reaction parameters, the methodology makes possible the obtention of amides with variable yields, while competing reactions such as the formation of disulfides and ureas can be limited. The process works well with aromatic thiols with electron donating groups (EDG) whereas other thiols give reaction with lower yields. The previous process has been transferred and optimized into flow equipment, thus allowing using less CO in a safer way, and permitting the scaling up of the synthesis. Two drugs, moclobemide and itopride were prepared with this methodology, albeit only in the second case with good results. A mechanistic pathway is proposed.
- Domínguez, Gema,Ordu?a, Jose Maria,Pérez-Castells, Javier
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p. 30398 - 30406
(2021/10/20)
-
- Metal-free Photocatalytic Intermolecular anti-Markovnikov Hydroamination of Unactivated Alkenes
-
The development of photocatalytic intermolecular hydroamination reaction between N-aminated dihydropyridines and unactivated alkenes is reported. Metal-free co-catalysts, rhodamine 6G and thiophenol, in presence of visible light are used to initiate the process. The transformation shows a broad substrate scope, both alkenes and amidyl radical can act as coupling partners. The radical strategy provides excellent anti-Markovnikov selectivity and regioselectivity in diene substrates.
- Li, Juncheng,Wang, Ting,Zhao, Gaoyuan
-
supporting information
p. 2650 - 2654
(2021/06/25)
-
- A case study of Pd?Pd intramolecular interaction in a benzothiazole based palladacycle; catalytic activity toward amide synthesisviaan isocyanide insertion pathway
-
An acetate bridge benzothiazolepalladacycle containing a rare metallophilic intramolecular Pd?Pd interaction was synthesized and thoroughly characterized. The synthesized benzothiazolepalladacycle directly anchored on SBA-15 to form an efficient heterogen
- Loni, Masood,Balmohammadi, Yaser,Dadgar Yeganeh, Reza,Imani, Kaveh,Notash, Behrouz,Bazgir, Ayoob
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supporting information
p. 3290 - 3297
(2021/02/26)
-
- Oxidative Amidation of Amines in Tandem with Transamidation: A Route to Amides Using Visible-Light Energy
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A methodology is reported for preparing amides using amines as an acyl source. The protocol involves the visible-light-promoted oxidative amidation of amines with pyrazole to synthesize N-acyl pyrazoles followed by transamidation. By combining photoredox catalysis with oxoammonium cations in the presence of sodium persulfate as a terminal oxidant, the N-acyl pyrazoles could be prepared efficiently and effectively using blue LEDs. The transamidation step was performed without the need to purify the N-acyl pyrazole intermediate, and a range of amides were generated in good to excellent yields.
- Nandi, Jyoti,Vaughan, Matthew Z.,Sandoval, Arturo León,Paolillo, Joshua M.,Leadbeater, Nicholas E.
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p. 9219 - 9229
(2020/08/14)
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- Cobalt-catalyzed aminocarbonylation of (hetero)aryl halides promoted by visible light
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The catalytic aminocarbonylation of (hetero)aryl halides is widely applied in the synthesis of amides but relies heavily on the use of precious metal catalysis. Herein, we report an aminocarbonylation of (hetero)aryl halides using a simple cobalt catalyst under visible light irradiation. The reaction extends to the use of (hetero)aryl chlorides and is successful with a broad range of amine nucleophiles. Mechanistic investigations are consistent with a reaction proceeding via intermolecular charge transfer involving a donor-acceptor complex of the substrate and cobaltate catalyst.
- Alexanian, Erik J.,Veatch, Alexander M.
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p. 7210 - 7213
(2020/07/23)
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- 2,2-Diazido-1,2-diarylethanones: Synthesis and Reactivity with Primary Amines
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We describe the synthesis and reactivity of a new class of diazidated compounds: the 2,2-diazido-1,2-diarylethanones. The diazides are easily accessible from 1,2-diarylethanones through a mild and simple protocol for the direct oxidative diazidation, using iodine and sodium azide in DMSO at room temperature. In studies towards their reactivity with amine nucleophiles under basic conditions, the diazides are shown to undergo a controlled fragmentation reaction that provides a straightforward access to the corresponding amides. In stark contrast to our previous results on the amine-triggered fragmentation of diazidated compounds, aromatic nitriles are found to be by-products of synthetic value. The net reaction consisting of diazidation and subsequent fragmentation, thus, provides a simple way to convert 1,2-diarylethanones into both aromatic amides and nitriles.
- Holzschneider, Kristina,H?ring, Andreas P.,Kirsch, Stefan F.
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p. 2824 - 2831
(2019/04/30)
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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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p. 845 - 850
(2019/01/30)
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- Integration of co2 reduction with subsequent carbonylation: Towards extending chemical utilization of co2
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Currently, it still remains a challenge to amplify the spectrum of chemical fixation of CO2, although enormous progress has been achieved in this field. In view of the widespread applications of CO in a myriad of industrial carbonylation processes, an alternative strategy is proposed in which CO2 reduction to CO is combined with carbonylation with CO generated ex situ, which affords efficiently pharmaceutically and agrochemically attractive molecules. As such, CO2 in this study was efficiently reduced by triphenysilane using CsF to CO in a sealed two-chamber reactor. Subsequently, palladium-catalyzed aminocar-bonylation, carbonylative Sonogashira coupling of aryl iodides, and rhodium(I)-mediated Pauson–Khand-type reaction proceeded smoothly to yield amides, alkynones, and bicyclic cy-clopentenones, respectively. Furthermore, the formed alkynones can further be successfully converted to a series of heterocycles, for example, pyrazoles, 3a-hydroxyisoxazolo[3,2-a]isoindol-8-(3aH)-one derivatives and pyrimidines in moderate yields. The striking features of this protocol include operational simplicity, high efficiency, and relatively broad application scope, which represents an alternative avenue for CO2 transformation.
- Lang, Xian-Dong,He, Liang-Nian
-
-
- A Visible-Light-Driven, Metal-free Route to Aromatic Amides via Radical Arylation of Isonitriles
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The photochemical metal-free carboamidation of aryl radicals has been exploited for the preparation of aromatic amides, including hetero- and polyaromatic derivatives, under visible light irradiation of arylazo sulfones in the presence of isocyanides in aqueous acetonitrile. The process was useful for the smooth preparation of the antidepressant moclobemide. (Figure presented.).
- Malacarne, Marco,Protti, Stefano,Fagnoni, Maurizio
-
supporting information
p. 3826 - 3830
(2017/11/15)
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- Nickel-catalyzed aminocarbonylation of aryl halides using carbamoylsilane as an amide source
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The nickel-catalyzed aminocarbonylation of aryl halides using carbamoylsilane as an amide source is developed. The procedure can prepare both tertiary and secondary amides, and is applicable to various carbamoylsilanes and aryl halides containing differen
- Wen, Xue-Ping,Han, Yu-Ling,Chen, Jian-Xin
-
p. 45107 - 45112
(2017/10/13)
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- Synthesis of Secondary Aromatic Amides via Pd-Catalyzed Aminocarbonylation of Aryl Halides Using Carbamoylsilane as an Amide Source
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Using N-methoxymethyl-N-organylcarbamoyl(trimethyl)silanes as secondary amides source, the direct transformation of aryl halides into the corresponding secondary aromatic amides via palladium-catalyzed aminocarbonylation is described. The reactions tolerated a broad range of functional groups on the aryl ring except big steric hindrance of substituent. The types and the relative position of substituents on the aryl ring impact the coupling efficiency.
- Tong, Wenting,Cao, Pei,Liu, Yanhong,Chen, Jianxin
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p. 11603 - 11608
(2017/11/10)
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- Atom economical synthesis of: N -alkylbenzamides via the iron(III) sulfate catalyzed rearrangement of 2-alkyl-3-aryloxaziridines in water and in the presence of a surfactant
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A green and mild synthetic route to N-alkylbenzamides involves eco-friendly one pot synthesis of 2-alkyl-3-aryloxaziridines from N-alkylamines and benzaldehydes followed by iron(iii) sulfate catalyzed rearrangement to the corresponding amides in water as the solvent and in the presence of sodium dodecyl sulfate as the surfactant. This green approach affords N-alkylbenzamides in high overall yields under simple and minimum manipulation.
- Kra?em, Jamil,Ollevier, Thierry
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supporting information
p. 1263 - 1267
(2017/08/15)
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- A high-efficient method for the amidation of carboxylic acids promoted by triphenylphosphine oxide and oxalyl chloride
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A effective amidation reaction of carboxylic acids with various amines promoted by triphenylphosphine oxide and oxalyl chloride under mild and neutral conditions has been developed. The feature of this procedure was the using and recycling of triphenylphosphine oxide at room temperature in 0.5?h. Furthermore a plausible mechanism also be deduced with the help of 31P NMR spectroscopy.
- Jiang, Lixue,Yu, Jing,Niu, Fanfan,Zhang, Derundong,Sun, Xiaoling
-
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- Appel reaction of carboxylic acids with tribromoisocyanuric acid/triphenylphosphine: A mild and acid-free preparation of esters and amides
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A facile and efficient method for esterification and amidation of carboxylic acids under neutral conditions has been developed. Esters and amides can be prepared by reacting a carboxylic acid (1 mmol) with tribromoisocyanuric acid (0.37 mmol) and triphenylphosphine (1 mmol) in dichloromethane at room temperature, followed by addition of an alcohol or an amine, respectively.
- Da Cunha Sindra, Haryadylla,De Mattos, Marcio C.S.
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p. 1129 - 1136
(2016/07/06)
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- Nickel-Catalyzed Reductive Addition of Aryl/Benzyl Halides and Pseudohalides to Carbodiimides for the Synthesis of Amides
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A Nickel-catalyzed reductive process is described for the direct amidation of benzyl and aryl halides using carbodiimides as the amidating agent. Moreover, aryl and benzyl C–O electrophiles such as triflate, acetate, tosylate, trityl ether, and pivalate were converted into amides using this method. The in-situ-generated Ni0acts as a catalyst for the reaction at room temperature for benzylic substrates, and 70 °C for aryl electrophiles. This new nickel-catalyzed reductive coupling protocol provides a general and operationally simple method for the synthesis of diverse amides using carbodiimides. Amides bearing bulky substituents can be synthesized by this strategy in high yield, which demonstrates its effectiveness in amide synthesis.
- Panahi, Farhad,Jamedi, Fereshteh,Iranpoor, Nasser
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p. 780 - 788
(2017/01/18)
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- TfOH catalyzed One-Pot Schmidt–Ritter reaction for the synthesis of amides through N-acylimides
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A One-Pot tandem Schmidt–Ritter process for the synthesis of amides has been developed using the super acid as catalyst. The in situ generated aryl/aliphatic nitriles from the reaction of aldehydes and sodium azide in the presence of TfOH and AcOH (Schmidt reaction) react with suitable alcohol (Ritter reaction) to give the amides. For the first time we observed that during the Schmidt process N-acylimides were generated along with nitriles, interestingly these N-acylimides also participated in the Ritter reaction.
- Singh, Garima,Dada, Ravikrishna,Yaragorla, Srinivasarao
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supporting information
p. 4424 - 4427
(2016/09/13)
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- Design and synthesis of ruthenium(II) OCO pincer type NHC complexes and their catalytic role towards the synthesis of amides
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The present contribution describes the synthesis and characterization of a family of robust ruthenium complexes, supported by a tridentate pincer ligand of the type bis-phenolate-N-heterocyclic carbene [ tBu(OCO) 2-] (NHC). Ruthenium(II) complexes (1-3) bearing bis-phenolate-N-heterocyclic carbene ligand were synthesized in good yields by the reaction of imidazolinium proligand (HL) with metal precursors [RuHCl(CO)(EPh3)2(B)] (E = P or As; B = PPh3, AsPh3 or Py) by transmetalation from the corresponding silver carbene complex. All the Ru(II)-NHC complexes have been characterized by elemental analyses, spectroscopic methods as well as ESI mass spectrometry. Based on the spectral results, an octahedral geometry was assigned for all the complexes. The tridentate nature of the tBu(OCO) 2- ligand as well as some level of steric protection provided by the t Bu groups may rationalize the excellent stability of the Ru-Ccarbene bond in the present systems. Moreover, for the explorations of catalytic potential of the synthesized compounds, all the three [Ru-NHC] complexes (1-3) were tested as catalysts for amidation of alcohols with amines. Notably, the complex 1 was found to be very efficient and versatile catalyst towards amidation of a wide range of alcohols with amines. [Figure not available: see fulltext.].
- Nirmala, Muthukumaran,Viswanathamurthi, Periasamy
-
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- Amidation via ligand-free direct oxidative C(sp3)-H/N[sbnd]H coupling with Cu-CPO-27 metal-organic framework as a recyclable heterogeneous catalyst
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A copper-based metal-organic framework Cu-CPO-27 was synthesized, and used as a recyclable catalyst for the amidation of unactivated alkanes by benzamides via direct oxidative C(sp3)-H/N[sbnd]H coupling under ligand-free conditions. Using a catalytic amount of the Cu-CPO-27 for the transformation, high yields of N-cyclohexyl benzamides were achieved. The Cu-CPO-27 was more catalytically active than other Cu-MOFs such as Cu3(BTC)2, Cu(BDC), Cu(EDB), Cu2(BPDC)2(BPY), Cu2(BDC)2(DABCO), and Cu2(EDB)2(BPY). The Cu-CPO-27 also exhibited advantages as compared to several copper-based salts, including Cu(OAc)2, CuCl2, CuBr, CuI, CuCl, Cu(NO3)2, and CuSO4. The Cu-CPO-27 catalyst could be reused several times for the amidation transformation while its catalytic activity was not decreased significantly. To the best of our knowledge, the amidation of unactivated alkanes by benzamides via direct oxidative C(sp3)-H/N[sbnd]H coupling was not previously performed under heterogeneous catalysis conditions.
- Hoang, Thanh T.,Nguyen, Hanh T.H.,Le, Tien T.,Le, Dung T.,Truong, Thanh,Phan, Nam T.S.
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p. 8241 - 8251
(2016/11/23)
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- A microwave-assisted highly practical chemoselective esterification and amidation of carboxylic acids
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The ubiquitousness of esters and amide functionalities makes their coupling reaction one of the most sought-after organic transformations. Herein, we have described an efficient microwave-assisted synthesis of esters and amides. Soluble triphenylphosphine, in conjugation with molecular iodine, gave the desired products without the requirement for a base/catalyst. In addition, a solid-phase synthetic route is incorporated for the said conversion, which has added advantages over solution-phase pathways, such as low moisture sensitivity, easy handling, isolation of the product by simple filtration, and reusability. In short, our method is simple, mild, green, and highly chemoselective in nature.
- Pathak, Gunindra,Das, Diparjun,Rokhum, Lalthazuala
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p. 93729 - 93740
(2016/10/21)
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- Significance of reagent addition sequence in the amidation of carboxylic acids mediated by PPh3 and I2
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The outcome of the amidation reaction mediated by PPh3-I2 was found to be highly dependent on the addition sequence of the reagents. When triethylamine was subjected to a mixture containing PPh3, I2, and a carboxylic acid, acid anhydride was generated almost instantly, before treatment with an amine, presumably via an attack of carboxylate ion onto the acyl function of an acyloxyphosphonium salt. Nevertheless, when a PPh3-I2 mixture was treated with an amine, then a carboxylic acid, prior to adding the base, amide was rapidly formed in high yield with high chemoselectivity, most likely through an intermediate O,N-pentacoordinate phosphorane species as confirmed by ESI-MS technique.
- Wangngae, Sirilak,Duangkamol, Chuthamat,Pattarawarapan, Mookda,Phakhodee, Wong
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p. 25789 - 25793
(2015/10/20)
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- Direct oxidative amidation between methylarenes and amines in water
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An environmentally friendly direct oxidative amidation between methylarenes and free amines was developed. The aromatic amide could be prepared efficiently from raw chemicals by employing TBHP as a "green" oxidant with co-catalysis of TBAI and FeCl3 in water.
- Wang, Tao,Yuan, Lin,Zhao, Zhenguang,Shao, Ailong,Gao, Meng,Huang, Yangfei,Xiong, Fei,Zhang, Huali,Zhao, Junfeng
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supporting information
p. 2741 - 2744
(2015/05/27)
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- Copper-catalyzed oxidative C(sp3)-H/N-H coupling of sulfoximines and amides with simple alkanes via a radical process
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A copper-catalyzed oxidative C(sp3)-H/N-H coupling of sulfoximines with simple alkanes was developed. This protocol involved C(sp3)-N bond formation via a radical pathway and tolerated a series of functional groups, such as chloro, m
- Teng, Fan,Sun, Song,Jiang, Yan,Yu, Jin-Tao,Cheng, Jiang
-
supporting information
p. 5902 - 5905
(2015/03/30)
-
- Synthesis of amides via copper-catalyzed amidation of aryl halides using isocyanides
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An efficient method for intermolecular CC cross-coupling reactions between isocyanides and aryl halides, catalyzed by copper(I) oxide, is developed. This transformation serves as a direct method for the preparation of benzamides in aqueous DMSO, in moderate to good yields.
- Yavari, Issa,Ghazanfarpour-Darjani, Majid,Bayat, Mohammad J.
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p. 4981 - 4982
(2015/01/09)
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- Amide synthesis from alcohols and amines catalyzed by a RuII-N-heterocyclic carbene (NHC)-carbonyl complex
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Treatment of [Ru2(CO)4(CH3CN)6](BF4)2 with 3-methyl-1-(pyridin-2-yl)-imidazolium bromide in the presence of tetrabutylammonium bromide at room temperature in dichloromethane affords a RuII-N-heterocyclic carbene-carbonyl complex [Ru(py-NHC)(CO)2Br2] (1). Catalyst 1 displays diverse substrate scope for phosphine-free acceptorless coupling between alcohols and amines to amides at low catalyst loading. A RuII-dihydride/Ru0 sequence is proposed in the catalytic cycle.
- Saha, Biswajit,Sengupta, Gargi,Sarbajna, Abir,Dutta, Indranil,Bera, Jitendra K.
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p. 124 - 130
(2014/12/11)
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- Ni-catalyzed direct reductive amidation via C-O bond cleavage
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A novel Ni-catalyzed reductive amidation of C(sp2)-O and C(sp3)-O electrophiles with isocyanates is described. This umpolung reaction allows for an unconventional preparation of benzamides using simple starting materials and easy-to-handle Ni catalysts.
- Correa, Arkaitz,Martin, Ruben
-
supporting information
p. 7253 - 7256
(2014/06/09)
-
- Photoinduced, copper-catalyzed alkylation of amides with unactivated secondary alkyl halides at room temperature
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The development of a mild and general method for the alkylation of amides with relatively unreactive alkyl halides (i.e., poor substrates for S N2 reactions) is an ongoing challenge in organic synthesis. We describe herein a versatile transition-metal-catalyzed approach: in particular, a photoinduced, copper-catalyzed monoalkylation of primary amides. A broad array of alkyl and aryl amides (as well as a lactam and a 2-oxazolidinone) couple with unactivated secondary (and hindered primary) alkyl bromides and iodides using a single set of comparatively simple and mild conditions: inexpensive CuI as the catalyst, no separate added ligand, and C-N bond formation at room temperature. The method is compatible with a variety of functional groups, such as an olefin, a carbamate, a thiophene, and a pyridine, and it has been applied to the synthesis of an opioid receptor antagonist. A range of mechanistic observations, including reactivity and stereochemical studies, are consistent with a coupling pathway that includes photoexcitation of a copper-amidate complex, followed by electron transfer to form an alkyl radical.
- Do, Hien-Quang,Bachman, Shoshana,Bissember, Alex C.,Peters, Jonas C.,Fu, Gregory C.
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supporting information
p. 2162 - 2167
(2014/03/21)
-
- Copper-catalyzed intermolecular amidation and imidation of unactivated alkanes
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We report a set of rare copper-catalyzed reactions of alkanes with simple amides, sulfonamides, and imides (i.e., benzamides, tosylamides, carbamates, and phthalimide) to form the corresponding N-alkyl products. The reactions lead to functionalization at secondary C-H bonds over tertiary C-H bonds and even occur at primary C-H bonds. [(phen)Cu(phth)] (1-phth) and [(phen)Cu(phth)2] (1-phth2), which are potential intermediates in the reaction, have been isolated and fully characterized. The stoichiometric reactions of 1-phth and 1-phth2 with alkanes, alkyl radicals, and radical probes were investigated to elucidate the mechanism of the amidation. The catalytic and stoichiometric reactions require both copper and tBuOOtBu for the generation of N-alkyl product. Neither 1-phth nor 1-phth2 reacted with excess cyclohexane at 100 C without tBuOOtBu. However, the reactions of 1-phth and 1-phth2 with tBuOOtBu afforded N-cyclohexylphthalimide (Cy-phth), N-methylphthalimide, and tert-butoxycyclohexane (Cy-OtBu) in approximate ratios of 70:20:30, respectively. Reactions with radical traps support the intermediacy of a tert-butoxy radical, which forms an alkyl radical intermediate. The intermediacy of an alkyl radical was evidenced by the catalytic reaction of cyclohexane with benzamide in the presence of CBr4, which formed exclusively bromocyclohexane. Furthermore, stoichiometric reactions of [(phen)Cu(phth)2] with tBuOOtBu and (Ph(Me)2CO) 2 at 100 C without cyclohexane afforded N-methylphthalimide (Me-phth) from β-Me scission of the alkoxy radicals to form a methyl radical. Separate reactions of cyclohexane and d12-cyclohexane with benzamide showed that the turnover-limiting step in the catalytic reaction is the C-H cleavage of cyclohexane by a tert-butoxy radical. These mechanistic data imply that the tert-butoxy radical reacts with the C-H bonds of alkanes, and the subsequent alkyl radical combines with 1-phth2 to form the corresponding N-alkyl imide product.
- Tran, Ba L.,Li, Bijie,Driess, Matthias,Hartwig, John F.
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supporting information
p. 2555 - 2563
(2014/03/21)
-
- Three-component metal-free arylation of isocyanides
-
Mumm's the word: The title reaction can be performed by the addition of isocyanides to benzenediazonium salts in the presence of sodium or potassium carboxylates. The reaction involves nitrilium intermediates which may be trapped by water or carboxylic ac
- Basavanag, Unnamatla M. V.,Dos Santos, Aurelie,El Kaim, Laurent,Gamez-Montano, Rocio,Grimaud, Laurence
-
supporting information
p. 7194 - 7197
(2013/07/26)
-
- Facile preparation of amides from carboxylic acids and amines with ion-supported Ph3P
-
Ion-supported Ph3P, 4-(diphenylphosphino)benzyltrimethylammonium bromide (IS-Ph3P), could be used for the facile amidation of a wide range of carboxylic acids with amines in the presence of bromotrichloromethane to provide the corresponding amides in good yields. In the present reaction, the desired amides were obtained in good yields with high purity by simple extraction of the reaction mixture with diethyl ether or chloroform and subsequent removal of the solvent from the extract. Moreover, ion-supported Ph3PO (IS-Ph3PO), which was a co-product derived from IS-Ph3P in the present reductive condensation, was recovered in high yield and could be reduced to IS-Ph3P for reuse in the same amidation of carboxylic acid.
- Kawagoe, Yuhsuke,Moriyama, Katsuhiko,Togo, Hideo
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p. 3971 - 3977
(2013/06/27)
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- Controlled and chemoselective reduction of secondary amides
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This communication describes a metal-free methodology involving an efficient and controlled reduction of secondary amides to imines, aldehydes, and amines in good to excellent yields under ambient pressure and temperature. The process includes a chemoselective activation of a secondary amide with triflic anhydride in the presence of 2-fluoropyridine. The electrophilic activated amide can then be reduced to the corresponding iminium using triethylsilane, a cheap, rather inert, and commercially available reagent. Imines can be isolated after a basic workup or readily transformed to the aldehydes following an acidic workup. The amine moiety can be accessed via a sequential reductive amination by the addition of silane and Hantzsch ester hydride in a one-pot reaction. Moreover, this reduction tolerates various functional groups that are usually reactive under reductive conditions and is very selective to secondary amides.
- Pelletier, Guillaume,Bechara, William S.,Charette, Andre B.
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supporting information; experimental part
p. 12817 - 12819
(2010/11/05)
-
- Hexabromoacetone as tribromoacetylating agent of alcohols and amines and as mediator in the conversion of carboxylic acids into amides in the presence of triphenylphosphine
-
Hexabromoacetone has been used as an alternative tribromoacetylating agent of primary alcohols and amines and as mediator in the conversion of carboxylic acids into amides in the presence of triphenylphosphine. The reactions have been performed under mild conditions with moderate to good yields. All the products have been adequately characterized by their physical and spectroscopic properties.
- Menezes, Fabrício G.,Kolling, Rosane,Bortoluzzi, Adaílton J.,Gallardo, Hugo,Zucco, César
-
body text
p. 2559 - 2561
(2009/08/09)
-
- Alkoxy- and amidocarbonylation of functionalised aryl and heteroaryl halides catalysed by a Bedford palladacycle and dppf: A comparison with the primary Pd(II) precursors (PhCN)2PdCl2 and Pd(OAc) 2
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The versatility of a Bedford-type palladacycle 1, namely [{Pd(-Cl){κ2-P,C-P(OC6H2-2,4- tBu2)(OC6H3-2,4-tBu 2)2}}2], as a primary Pd source, in combination with the ligand bis-1,1′-(diphenylphosphino)ferrocene (dppf) has been established in carbonylation reactions of aryl and heteroaryl bromides with methanol, piperidine and related nucleophiles. Palladacycle 1 has been compared with other primary Pd sources, e.g. (PhCN)2PdCl2 and Pd(OAc)2. The efficacy of the carbonylation processes appear to be linked to the [Pd] concentration, substrate: catalyst ratio, CO pressure and reaction temperature. In amidocarbonylation, double carbonylation is observed for certain organohalides. In the case of 2,5-dibromopyridine, regioselective amination (Hartwig-Buchwald type) also occurs as a side-reaction. This journal is The Royal Society of Chemistry.
- Fairlamb, Ian J. S.,Grant, Stephanie,McCormack, Peter,Whittall, John
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p. 859 - 865
(2007/10/03)
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- Radical mediated-direct conversion of aldehydes into acid bromides
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A method of preparing acid bromides directly from aldehydes with Br3CCO2Et under radical conditions was developed. Aromatic aldehydes with electron-donating group were found to be more reactive than aromatic aldehydes with electron-w
- Kang, Dong Ho,Joo, Tae Young,Chavasiri, Warinthorn,Jang, Doo Ok
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p. 285 - 287
(2007/10/03)
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- A mild and efficient reaction for conversion of carboxylic acids into acid bromides with ethyl tribromoacetate/triphenylphosphine under acid-free conditions
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Acid bromides were prepared efficiently from carboxylic acids with readily available ethyl tribromoacetate and triphenylphosphine at room temperature under neutral conditions. The present process is applicable to the preparation of various acid bromides from aromatic and aliphatic carboxylic acids. Aromatic carboxylic acids were found to be more reactive than aliphatic carboxylic acids under reaction conditions.
- Kang, Dong Ho,Joo, Tae Young,Lee, Eun Hwa,Chaysripongkul, Skaydaw,Chavasiri, Warinthorn,Jang, Doo Ok
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p. 5693 - 5696
(2007/10/03)
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- Indium-mediated mild and facile method for the synthesis of amides
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Indium-mediated coupling reactions of acyl chlorides and amines for the synthesis of amide bonds are described. The reaction afforded high yields of the desired amides under mild and neutral conditions, and it was applicable also to the preparation of peptides without epimerization.
- Cho, Dae Hyan,Jang, Doo Ok
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p. 2285 - 2287
(2007/10/03)
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- A novel approach for the one-pot preparation of α-amino amides by pd-catalyzed double carbohydroamination
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A new domino reaction sequence, a palladium-catalyzed double carbohydroamination, which involves double carbonylation, amine condensation, and hydrogenation from an aryl iodide(1), a primary amine (2), and synthetic gas has been realized as a novel synthetic means for the one-pot synthesis of α-amino amides (3).
- Lin, Yong-Shou,Alper, Howard
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p. 779 - 781
(2007/10/03)
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- Acid-catalysed N-alkyl heterolysis of tertiary pyridinecarboxamides and benzamides under mild conditions
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Tertiary pyridinecarboxamides 1-9 and related benzamides 10-18 bearing a tert-butyl substituent were found to undergo alkyl-nitrogen heterolysis under unusually mild conditions. Accordingly, the corresponding secondary amides 19-33 have been isolated in high yields as the sole reaction product. Through a kinetic study based on pH-rate profiles and activation parameters, we have shown that the alkyl-nitrogen fission involved an initial protonation of the amide group that would concern the oxygen atom.
- Auzeil, Nicolas,Largeron, Martine,Fleury, Maurice-Bernard
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p. 1703 - 1709
(2007/10/03)
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- A mild and efficient procedure for the preparation of acid chlorides from carboxylic acids
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Various carboxylic acids are converted into the corresponding acid chlorides by treatment with trichloroacetonitrile and triphenylphosphine in methylene chloride at room temperature. Aryl acids show higher reactivity than alkyl acids under the conditions.
- Jang, Doo Ok,Park, Doo Jin,Joonggon, Kim
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p. 5323 - 5326
(2007/10/03)
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