- Secondary amide-based linkers for solid phase organic synthesis
-
The electron rich benzaldehyde derivatives 4-hydroxybenzaldehyde and 2-methoxy-4-hydroxybenzaldehyde have been investigated for use as linkers for solid phase organic synthesis. Reductive amination of these aldehydes attached to ArgoGel resins with a model primary amine gave the corresponding benzylic secondary amines. These compounds were then converted to the corresponding ureas, sulfonamides, aryl amides, and alkyl amides by derivatization with an appropriate electrophile. The desired secondary amide derivative was then cleaved from the support by treatment with trifluoroacetic acid to provide essentially quantitative yields of products in high purity.
- Swayze, Eric E.
-
-
Read Online
- 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)
-
- Nickel-catalyzed reductive amidation of aryl-triazine ethers
-
The reaction of activated phenolic compounds, 2,4,6-triaryloxy-1,3,5-triazine (aryl-triazine ethers), with various isocyanates or carbodiimides in the presence of a nickel pre-catalyst resulted in the synthesis of aryl amides in good to excellent yields.
- Heravi, Majid M.,Panahi, Farhad,Iranpoor, Nasser
-
supporting information
p. 1992 - 1995
(2020/02/22)
-
- An efficient, one-pot transamidation of 8-aminoquinoline amides activated by tertiary-butyloxycarbonyl
-
The efficient, one-pot access to the transamidation of 8-aminoquinoline (8-AQ), notorious for its harsh removal conditions, has been widely employed as an auxiliary in C–H functionalization reactions due to its strong directing ability. In this study, the facile and mild Boc protection of the corresponding 8-AQ amide was critical to activate the amide C(acyl)–N bond by twisting its geometry to lower the amidic resonance energy. Both aryl and alkyl amines proceeded transamidation in one-pot, user-friendly conditions with excellent yields.
- Wu, Wengang,Yi, Jun,Xu, Huipeng,Li, Shuangjun,Yuan, Rongxin
-
-
- Amide Boc de-protection method
-
The invention discloses an amide Boc de-protection method. The amide Boc de-protection method includes carrying out reaction on Boc protected amide III and amine IV under the condition of the presenceof palladium catalysts to generate new amide V. 8-aminoquinoline can be used as a guide group to be applied to chemical reaction, a process for synthesizing the new amide by means of de-protection isprovided, protecting groups can be easily removed by means of palladium catalysis, the new amide can be generated, and the reaction is high in efficiency. The amide Boc de-protection method has the advantages of environmental friendliness, recyclability and the like.
- -
-
Paragraph 0035; 0129; 0130; 0131
(2018/09/13)
-
- 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
-
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.
-
p. 8241 - 8251
(2016/11/23)
-
- An attractive route to transamidation catalysis: Facile synthesis of new o-aryloxide-N-heterocyclic carbene ruthenium(II) complexes containing trans triphenylphosphine donors
-
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
-
-
- A general continuous flow method for palladium catalysed carbonylation reactions using single and multiple tube-in-tube gas-liquid microreactors
-
A series of continuous flow chemistry processes that facilitate the palladium-catalysed carbonylation of aryl and vinyl iodides and aryl bromides with a range of alkoxy, hydroxy and amino nucleophiles is reported. Harnessing a semipermeable Teflon AF-2400 Tube-in-Tube assembly, these reactors permit the controlled transport of carbon monoxide into solution at elevated pressure to generate homogeneous flow streams, avoiding some potential issues associated with segmented flow gas-liquid reactors. As the volume of pressurised gas contained within the device is low, the hazards associated with this are potentially mitigated relative to comparable batch processes. We also show how the incorporation of a second in-line gas-flow reactor allows for the sequential introduction of two gases (carbon monoxide and a gaseous nucleophile) into the reaction stream. A Teflon AF-2400 Tube-in-Tube reactor facilitates the use of carbon monoxide in continuous-flow C-C bond forming reactions providing esters, amides, carboxylic acids, lactones and lactams. Two reactors can be used in series to permit the sequential addition of two reactive gases (CO and Me2NH) into the flow stream.
- Gross, Ulrike,Koos, Peter,O'brien, Matthew,Polyzos, Anastasios,Ley, Steven V.
-
supporting information
p. 6418 - 6430
(2016/02/18)
-
- Synthesis of amides via copper-catalyzed amidation of aryl halides using isocyanides
-
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.
-
p. 4981 - 4982
(2015/01/09)
-
- Efficient copper(II)-catalyzed transamidation of non-activated primary carboxamides and ureas with amines
-
Amid(e) them all: Primary carboxamides and ureas react with aromatic and aliphatic amines in the presence of a copper catalyst to give a wide range of functionalized amides (see scheme). Copyright
- Zhang, Min,Imm, Sebastian,Baehn, Sebastian,Neubert, Lorenz,Neumann, Helfried,Beller, Matthias
-
supporting information; experimental part
p. 3905 - 3909
(2012/06/04)
-
- Pd(ii)-catalyzed decarboxylative cross-coupling of oxamic acids with potassium phenyltrifluoroborates under mild conditions
-
A novel Pd-catalyzed decarboxylative cross-coupling of oxamic acids with potassium phenyltrifluoroborates has been realized under mild reaction conditions. This method provides an efficient access to N-mono- or N,N-disubstituted benzamides and benzoates.
- Li, Mingzong,Wang, Cong,Fang, Ping,Ge, Haibo
-
supporting information; experimental part
p. 6587 - 6589
(2011/06/25)
-
- Novel sparteine-mediated enantio-dichotomic formal synthesis of (R)-(-)- and (S)-(+)-curcuphenol
-
High and opposite enantiodiscriminations were observed between tertiary amides and secondary amides in the sparteine-mediated lateral metalation-allylation of 2-ethyl-m-toluamide derivatives (2a, 2e). The results described above have been applied for the formal synthesis of both enantiomers of curcuphenol. The brief mechanistic studies suggested that stereoinformation was introduced after the deprotonation step.
- Kimachi,Takemoto
-
p. 2700 - 2704
(2007/10/03)
-
- One-pot reduction of carboxylic acids via O-acylisoureas
-
A simple one-pot reduction of aliphatic carboxylic acids to primary alcohols, by treatment with dicyclohexylcarbodiimide followed by lithium borohydride, is reported. The same methodology applied to aromatic carboxylic acids is shown to give a mixture of the alcohols with N- cyclohexylcarboxamides.
- Herbert, John M.,Hewson, Alan T.,Peace, James E.
-
p. 823 - 832
(2007/10/03)
-