- Sulfinyl isobutyramide as an auxiliary for palladium(II)-catalyzed C-H arylation and iodination of benzylamine derivatives
-
A novel readily available bidentate 2-methylsulfinyl isobutyramide directing group has been developed for benzylamine derivatives. It promoted ortho-C-H arylation and iodination of various substrates in good to excellent yields. The auxiliary is promising to be used in organic synthesis due to its versatility and convenient preparation from inexpensive materials.
- Wang, Rui,Ding, Yongzheng,Li, Gang
-
-
Read Online
- Triphenyl borate catalyzed synthesis of amides from carboxylic acids and amines
-
Herein we report triphenyl borate as a new catalyst for synthesis of amides by catalytic condensation of carboxylic acids and amines. Our protocol is applicable for synthesis of wide range of amides furnishing excellent yields up to 92%. In addition developed method requires low catalyst loading, short time, less amount of solvent, works under air atmosphere and notably no need of azeotropic reflux using special Dean Stark apparatus or molecular sieves.
- Ghorpade, Seema A.,Sawant, Dinesh N.,Sekar, Nagaiyan
-
-
Read Online
- AMINE-BORANES AS BIFUNCTIONAL REAGENTS FOR DIRECT AMIDATION OF CARBOXYLIC ACIDS
-
The present invention generally relates to a process for selective and direct activation and subsequent amidation of aliphatic and aromatic carboxylic acids to afford an amide R3CONR1R2. That the process is capable of delivering gaseous or low-boiling point amines provides a major advantage over existing methodologies, which involves an intermediate of triacyloxyborane-amine complex [(R3CO2)3—B—NHR1R2]. This procedure readily produces primary, secondary, and tertiary amides, and is compatible with the chirality of the acid and amine involved. The preparation of known pharmaceutical molecules and intermediates has also been demonstrated.
- -
-
Paragraph 0008-0009; 0063-0064
(2022/03/04)
-
- Amide Bond Formation via the Rearrangement of Nitrile Imines Derived from N-2-Nitrophenyl Hydrazonyl Bromides
-
We report how the rearrangement of highly reactive nitrile imines derived from N-2-nitrophenyl hydrazonyl bromides can be harnessed for the facile construction of amide bonds. This amidation reaction was found to be widely applicable to the synthesis of primary, secondary, and tertiary amides and was used as the key step in the synthesis of the lipid-lowering agent bezafibrate. The orthogonality and functional group tolerance of this approach was exemplified by the N-acylation of unprotected amino acids.
- Boyle, Mhairi,Livingstone, Keith,Henry, Martyn C.,Elwood, Jessica M. L.,Lopez-Fernandez, J. Daniel,Jamieson, Craig
-
p. 334 - 338
(2022/01/20)
-
- Ammonia-borane as a Catalyst for the Direct Amidation of Carboxylic Acids
-
Ammonia-borane serves as an efficient substoichiometric (10%) precatalyst for the direct amidation of both aromatic and aliphatic carboxylic acids. In situ generation of amine-boranes precedes the amidation and, unlike the amidation with stoichiometric amine-boranes, this process is facile with 1 equiv of the acid. This methodology has high functional group tolerance and chromatography-free purification but is not amenable for esterification. The latter feature has been exploited to prepare hydroxyl- and thiol-containing amides.
- Ramachandran, P. Veeraraghavan,Hamann, Henry J.
-
supporting information
p. 2938 - 2942
(2021/05/04)
-
- Efficient and accessible silane-mediated direct amide coupling of carboxylic acids and amines
-
A straightforward method for the direct synthesis of amides from amines and carboxylic acids without exclusion of air or moisture using diphenylsilane with N-methylpyrrolidine has been developed. Various amides are made efficiently, and broad functional group compatibility is shown through a Glorius robustness study. A gram-scale synthesis demonstrates the scalability of this method. This journal is
- D'Amaral, Melissa C.,Jamkhou, Nick,Adler, Marc J.
-
supporting information
p. 288 - 295
(2021/01/28)
-
- Radical-Mediated Activation of Esters with a Copper/Selectfluor System: Synthesis of Bulky Amides and Peptides
-
Herein, we describe a new approach for the activation of esters via a radical-mediated process enabled by a copper/Selectfluor system. A variety of para-methoxybenzyl esters derived from bulky carboxylic acids and amino acids can be easily converted into the corresponding acyl fluorides, directly used in the one-pot synthesis of amides and peptides. As a proof of concept, this method was applied to the iterative formation of sterically hindered amide bonds.
- Matsumoto, Akira,Wang, Zhe,Maruoka, Keiji
-
p. 5401 - 5411
(2021/04/12)
-
- N -Heterocyclic carbene (NHC) catalyzed amidation of aldehydes with amines via the tandem N -hydroxysuccinimide ester formation
-
A facile method for the amidation of aldehydes by a cascade approach was developed. This methodology, reported for the first time, uses a N-heterocyclic carbene (NHC) as the catalyst, and N-hydroxysuccinimide (NHS) mediated synthesis of amides utilising TBHP as the oxidant. Various substituted aldehydes reacted smoothly with NHS giving the corresponding active esters in moderate to good yields, which facilely converted into amides in one pot. In addition, the drug moclobemide was synthesized to represent the practical utility of the developed methodology. This journal is
- Singh, Ashmita,Narula
-
p. 7486 - 7490
(2021/05/13)
-
- Acetyl nitrate mediated conversion of methyl ketones to diverse carboxylic acid derivatives
-
The development of a novel acetyl nitrate mediated oxidative conversion of methyl ketones to carboxylic acid derivatives is described. By analogy to the haloform reaction and supported by experimental and computational investigation we propose a mechanism for this transformation.
- Bernard, Josephine,Capilato, Joseph N.,Hoy, Erik P.,Mattiucci, Joseph,Pellegrinelli, Peter J.,Perez, Lark J.,Philippi, Shane,Schnorbus, Logan
-
supporting information
p. 5298 - 5302
(2021/06/30)
-
- Homoleptic Bis(trimethylsilyl)amides of Yttrium Complexes Catalyzed Hydroboration Reduction of Amides to Amines
-
Homoleptic lanthanide complex Y[N(TMS)2]3 is an efficient homogeneous catalyst for the hydroboration reduction of secondary amides and tertiary amides to corresponding amines. A series of amides containing different functional groups such as cyano, nitro, and vinyl groups were found to be well-tolerated. This transformation has also been nicely applied to the synthesis of indoles and piribedil. Detailed isotopic labeling experiments, control experiments, and kinetic studies provided cumulative evidence to elucidate the reaction mechanism.
- Ye, Pengqing,Shao, Yinlin,Ye, Xuanzeng,Zhang, Fangjun,Li, Renhao,Sun, Jiani,Xu, Beihang,Chen, Jiuxi
-
supporting information
p. 1306 - 1310
(2020/02/22)
-
- N-Hydroxybenzimidazole as a structurally modifiable platform forN-oxyl radicals for direct C-H functionalization reactions
-
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
-
p. 5772 - 5778
(2020/06/22)
-
- Efficient cleavage of tertiary amide bonds: Via radical-polar crossover using a copper(ii) bromide/Selectfluor hybrid system
-
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
-
p. 12323 - 12328
(2020/12/08)
-
- Amine-boranes as Dual-Purpose Reagents for Direct Amidation of Carboxylic Acids
-
Amine-boranes serve as dual-purpose reagents for direct amidation, activating aliphatic and aromatic carboxylic acids and, subsequently, delivering amines to provide the corresponding amides in up to 99% yields. Delivery of gaseous or low-boiling amines as their borane complexes provides a major advantage over existing methodologies. Utilizing amine-boranes containing borane incompatible functionalities allows for the preparation of functionalized amides. An intermolecular mechanism proceeding through a triacyloxyborane-amine complex is proposed.
- Choudhary, Shivani,Hamann, Henry J.,Ramachandran, P. Veeraraghavan
-
supporting information
(2020/11/13)
-
- Water-Tolerant and Atom Economical Amide Bond Formation by Metal-Substituted Polyoxometalate Catalysts
-
A simple, safe, and inexpensive amide bond formation directly from nonactivated carboxylic acids and free amines is presented in this work. Readily available Zr(IV)- and Hf(IV)-substituted polyoxometalates (POM) are shown to be catalysts for the amide bond formation reaction under mild conditions, low catalyst loading, and without the use of water scavengers, dry solvents, additives for facilitating the amine attack, or specialized experimental setups commonly employed to remove water. Detailed mechanistic investigations revealed the key role of POM scaffolds which act as inorganic ligands to protect Zr(IV) and Hf(IV) Lewis acidic metals against hydrolysis and preserve their catalytic activity in amide bond formation reactions. The catalysts are compatible with a range of functional groups and heterocycles useful for medicinal, agrochemical, and material chemists. The robustness of the Lewis acid-POM complexes is further supported by the catalyst reuse without loss of activity. This prolific combination of Zr(IV)/Hf(IV) and POMs inaugurates a powerful class of catalysts for the amide bond formation, which overcomes key limitations of previously established Zr(IV)/Hf(IV) salts and boron-based catalysts.
- De Azambuja, Francisco,Parac-Vogt, Tatjana N.
-
p. 10245 - 10252
(2019/11/03)
-
- A solid-supported arylboronic acid catalyst for direct amidation
-
An efficient heterogeneous amidation catalyst has been prepared by co-polymerisation of styrene, DVB with 4-styreneboronic acid, which shows wide substrate applicability and higher reactivity than the equivalent homogeneous phenylboronic acid, suggesting potential cooperative catalytic effects. The catalyst can be easily recovered and reused; suitable for use in packed bed flow reactors.
- Du, Yihao,Barber, Thomas,Lim, Sol Ee,Rzepa, Henry S.,Baxendale, Ian R.,Whiting, Andrew
-
supporting information
p. 2916 - 2919
(2019/03/27)
-
- Visible light-induced transformation of aldehydes to esters, carboxylic anhydrides and amides
-
A transition metal- and organophotocatalyst free synthesis of esters, carboxylic anhydrides and amides from aldehydes induced by visible-light has been reported. The proposed methodology can be carried out by the use of sunlight or artificial visible light as a blue LED source. The methodology has a very broad applicability and the desired products are obtained in very satisfactory yields.
- Gaspa, Silvia,Raposo, Inês,Pereira, Leonor,Mulas, Gabriele,Ricci, Pier Carlo,Porcheddu, Andrea,De Luca, Lidia
-
supporting information
p. 10711 - 10715
(2019/07/15)
-
- Tetramethyl Orthosilicate (TMOS) as a Reagent for Direct Amidation of Carboxylic Acids
-
Tetramethyl orthosilicate (TMOS) is shown to be an effective reagent for direct amidation of aliphatic and aromatic carboxylic acids with amines and anilines. The amide products are obtained in good to quantitative yields in pure form directly after workup without the need for any further purification. A silyl ester as the putative activated intermediate is observed by NMR methods. Amidations on a 1 mol scale are demonstrated with a favorable process mass intensity.
- Braddock, D. Christopher,Lickiss, Paul D.,Rowley, Ben C.,Pugh, David,Purnomo, Teresa,Santhakumar, Gajan,Fussell, Steven J.
-
supporting information
p. 950 - 953
(2018/02/23)
-
- One-Pot Reductive Allylation of Amides by Using a Combination of Titanium Hydride and an Allylzinc Reagent: Application to a Total Synthesis of (-)-Castoramine
-
A one-pot direct reductive allylation protocol has been developed for the synthesis of secondary amines by using titanium hydride and an allylzinc reagent. This protocol is applicable to a broad range of substrates, including acyclic amides, benzamides, α,β-unsaturated amides, and lactams. The stereochemical outcome obtained from the reaction with crotylzinc reagent suggested that the allylation reaction proceeds through a six-membered cyclic transition state. A total synthesis of (-)-castoramine was accomplished by following this protocol for the highly stereoselective construction of contiguous stereocenters.
- Itabashi, Suguru,Shimomura, Masashi,Sato, Manabu,Azuma, Hiroki,Okano, Kentaro,Sakata, Juri,Tokuyama, Hidetoshi
-
supporting information
p. 1786 - 1790
(2018/07/03)
-
- Ferric(III) Chloride Catalyzed Halogenation Reaction of Alcohols and Carboxylic Acids Using α,α-Dichlorodiphenylmethane
-
A new method for chlorination of alcohols and carboxylic acids, using α,α-dichlorodiphenylmethane as the chlorinating agent and FeCl3 as the catalyst, was developed. The method enables conversions of various alcohols and carboxylic acids to their corresponding alkyl and acyl chlorides in high yields under mild conditions. Particulary interesting is the observation that the respective alkyl bromides and iodides can be generated from alcohols when either LiBr or LiI are present in the reaction mixtures.
- Lee, Chang-Hee,Lee, Soo-Min,Min, Byul-Hana,Kim, Dong-Su,Jun, Chul-Ho
-
supporting information
p. 2468 - 2471
(2018/04/25)
-
- Transition-Metal- and Halogen-Free Oxidation of Benzylic sp 3 C-H Bonds to Carbonyl Groups Using Potassium Persulfate
-
Aryl carbonyl compounds including acetophenones, benzophenones, imides, and benzoic acids are prepared from benzyl substrates using potassium persulfate as oxidant with catalytic pyridine in acetonitrile under mild conditions. Neither transition metals nor halogens are involved in the reactions.
- Hu, Yixin,Zhou, Lihong,Lu, Wenjun
-
supporting information
p. 4007 - 4016
(2017/08/29)
-
- A mixed anhydride approach to the preparation of sulfinate esters and allylic sulfones: Trimethylacetic p-toluenesulfinic anhydride
-
A reagent combination of toluenesulfinic acid and trimethylacetyl chloride affords a putative trimethylacetic p-toluenesulfinic anhydride. This reagent has been used to prepare a series of sulfinate esters from primary and secondary alcohols. In addition, the reagent was used to convert Baylis-Hillman substrates into allylic sulfones. Attempts to use the reagent to convert amines to sulfinamides were unsuccessful. In contrast, the use of 2-pyrrolidinone afforded N-p-toluenesulfinyl pyrrolidinone in 64% yield. The use of a chiral 4-benzyl-1,3-oxazolidinone or 4-benzyl-1,3-oxazolidine-2-thione led to the isolation of S-p-tolyl p-toluenethiosulfonate.
- Jacobsen, Eric,Chavda, Mihir K.,Zikpi, Kokou M.,Waggoner, Stephanie L.,Passini, Daniel J.,Wolfe, Jesse A.,Larson, Robert,Beckley, Chelsea,Hamaker, Christopher G.,Hitchcock, Shawn R.
-
p. 3073 - 3077
(2017/07/17)
-
- Cleavage of 1,3-dicarbonyls through oxidative amidation
-
A mild and convenient protocol for the oxidative cleavage of 1,3-diketone compounds is described. Under metal-free conditions, the method converts the 1,3-dicarbonyls into amides when treated with (nBu4N)N3 and iodine in the presence of an amine at room temperature. Using this method, a range of 1,3-dicarbonyls with various structural motifs including sterically demanding substituents and ordinary functional groups were easily fragmented, and it is demonstrated that cyclic 1,3-dicarbonyls can be directly transformed into acyclic diamides through ring-opening. Initial mechanistic studies show that diazidation of the enol form is followed by nucleophilic substitution with the amine.
- Biallas, Phillip,H?ring, Andreas P.,Kirsch, Stefan F.
-
supporting information
p. 3184 - 3187
(2017/04/21)
-
- An Unconventional Reaction of 2,2-Diazido Acylacetates with Amines
-
We have discovered that 2,2-diazido acylacetates, a class of compounds with essentially unknown reactivity, can be coupled to amines through a new strategy that does not involve any reagents. 2,2-Diazido acetate is the unconventional leaving group under carbon–carbon bond cleavage. This reaction leads to the construction of amide bonds, tolerates various functionalities and is performed equally well in numerous solvents under experimentally simple conditions. We also demonstrate that the isolation of the 2,2-diazido acylacetate compounds can be circumvented: Acylacetates were easily fragmented when treated with (Bu4N)N3 and iodine in the presence of an amine at room temperature. By using this method, a broad range of acylacetates with various structural motifs were directly transformed into amides.
- H?ring, Andreas P.,Biallas, Phillip,Kirsch, Stefan F.
-
p. 1526 - 1539
(2017/04/01)
-
- NECROSIS INHIBITORS
-
The invention provides amides that inhibit cellular necrosis and/or human receptor interacting protein 1 kinase (RIP1), including corresponding sulfonamides, and pharmaceutically acceptable salts, hydrides and stereoisomers thereof. The compounds are employed in pharmaceutical compositions, and methods of making and use, including treating a person in need thereof with an effective amount of the compound or composition, and detecting a resultant improvement in the person's health or condition.
- -
-
Paragraph 0185; 0186; 0187
(2016/07/27)
-
- Rhodium-Catalyzed oxidative amidation of sterically hindered aldehydes and alcohols
-
A rhodium-catalyzed oxidative amidation reaction has been developed with sterically hindered aldehydes and alcohols for the synthesis of amides containing a quaternary carbon at the α position. A variety of amine nucleophiles, both aliphatic and aromatic, are employed and afford the corresponding amides in good to excellent yields. Finally, mechanistic studies are performed to gain insight into both catalytic cycles.
- Nguyen, Trang T.,Hull, Kami L.
-
p. 8214 - 8218
(2018/05/23)
-
- Zirconium-catalyzed direct amide bond formation between carboxylic esters and amines
-
Development of catalytic amide bond formation reactions from readily available starting materials remains a challenging task for modern organic chemistry. Herein, we report that unactivated carboxylic esters and amines react in the presence of 10 mol % of zirconocene dichloride (Cp2ZrCl2) in toluene at 110 °C to afford amides in very good to excellent conversions. The Zr-catalyzed reaction is amenable for the amidation of aliphatic and aromatic carboxylic esters with primary and secondary amines. The reaction proceeds with almost complete retention of configuration for chiral esters and chiral amines.
- Lenstra, Danny C.,Nguyen, D. Thao,Mecinovi?, Jasmin
-
p. 5547 - 5553
(2015/08/03)
-
- Copper(I)-Catalyzed Reductive Cross-Coupling of N-Tosylhydrazones with Amides: A Straightforward Method for the Construction of C(sp3)- N Amide Bonds from Aldehydes
-
A method for the one-pot synthesis of substituted amides from aldehydes and amides is presented. Namely, condensation of aldehydes with N-tosylhydrazide generated the N-tosylhydrazones which were then reductively cross-coupled in situ with primary or secondary amides in the presence of a copper catalyst to afford secondary or tertiary amides, respectively. The reaction proceeded efficiently for a wide range of aldehydes and amides under the optimized conditions, i.e., 10 mol% of tetrakis(acetonitrile)copper(I) tetrafluoroborate [Cu(CH3CN)4BF4], 1 mol% of tetra-n-butylammonium iodide [(n-Bu)4NI], and sodium hydroxide [NaOH] as base in tetrahydrofuran (THF) at 80 C. As a result, the method provides a straightforward route for the synthesis of substituted amides from readily available aldehydes via a transition metal-catalyzed C(sp3)- N amide bond forming reaction.
- Xu, Peng,Han, Fu-She,Wang, Yan-Hua
-
supporting information
p. 3441 - 3446
(2016/01/25)
-
- Steric and Electronic Effects in the Synthesis and Regioselective Hydrolysis of Unsymmetrical Imides
-
The AgI-promoted coupling reaction of thioamides and carboxylic acids is shown to be a useful method for the generation of unsymmetrical imides. The reaction proceeds efficiently with unhindered and electron-rich or neutral coupling partners, but not with hindered thioamides (such as thiopivalamides) or electron deficient thioamides (such as trifluorothioacetamides). Intriguingly, thioformamides are also ineffective coupling partners, despite having minimal steric or electronic influence. Hindered carboxylic acid coupling partners (such as pivalic acid) are tolerated, but electron deficient acids, such as trifluoroacetic acid, are ineffective coupling partners. Furthermore, an interplay of both steric and electronic effects is observed in the subsequent hydrolysis of unsymmetrical imides. Imides with a dimethoxybenzoyl group give high regioselectivity upon hydrolysis, favouring cleavage of the distal acyl group. Imides with a p-nitrobenzoyl or pivaloyl group give reversed selectivity, favouring cleavage of the proximal acyl group.
- Shang, Jing,Pourvali, Aysa,Cochrane, James R.,Hutton, Craig A.
-
p. 1854 - 1858
(2015/12/26)
-
- Synergistic cascade catalysis by metal nanoparticles and Lewis acids in hydrogen autotransfer
-
Of the many types of catalysis involving two or more catalysts, synergistic catalysis is of great interest because novel reactions or reaction pathways may be discovered when there is synergy between the catalysts. Herein, we describe a synergistic cascade catalysis, in which immobilized Au/Pd bimetallic nanoparticles and Lewis acids work in tandem to achieve the N-alkylation of primary amides to secondary amides with alcohols via hydrogen autotransfer. When Au/Pd nanoparticles were used with metal triflates, a significant rate acceleration was observed, and the desired secondary amides were obtained in excellent yields. The metal triflate is thought to not only facilitate the addition of primary amides to aldehydes generated in situ, but also enhance the returning of hydrogen from nanoparticles to hydrogen-accepting intermediates. This resulted in a more rapid turnover of the nanoparticle catalyst, and ultimately translated into an increase in the overall rate of the reaction. The two catalysts in this co-catalytic system work in a synergistic and cascade fashion, resulting in an efficient hydrogen autotransfer process.
- Choo, Gerald C. Y.,Miyamura, Hiroyuki,Kobayashi, Shuˉ
-
p. 1719 - 1727
(2015/08/12)
-
- C-N Coupling of Amides with Alcohols Catalyzed by N-Heterocyclic Carbene-Phosphine Iridium Complexes
-
N-Heterocyclic carbene-phosphine iridium complexes (NHC-Ir) were developed/found to be a highly reactive catalyst for N-monoalkylation of amides with alcohols via hydrogen transfer. The reaction produced the desired product in high isolated yields using a wide range of substrates with low catalyst loading and short reaction times.
- Kerdphon, Sutthichat,Quan, Xu,Parihar, Vijay Singh,Andersson, Pher G.
-
p. 11529 - 11537
(2015/12/04)
-
- Semi-catalytic reduction of secondary amides to imines and aldehydes
-
Secondary amides can be reduced by silane HSiMe2Ph into imines and aldehydes by a two-stage process involving prior conversion of amides into iminoyl chlorides followed by catalytic reduction mediated by the ruthenium complex [Cp(i-Pr3P)Ru(NCCH3)2]PF6 (1). Alkyl and aryl amides bearing halogen, ketone, and ester groups were converted with moderate to good yields under mild reaction conditions to the corresponding imines and aldehydes. This procedure does not work for substrates bearing the nitro-group and fails for heteroaromatic amides. In the case of cyano substituted amides, the cyano group is reduced to imine.
- Lee, Sun-Hwa,Nikonov, Georgii I.
-
supporting information
p. 8888 - 8893
(2014/06/09)
-
- METHOD FOR THE CATALYTIC REDUCTION OF ACID CHLORIDES AND IMIDOYL CHLORIDES
-
The present application relates to methods for the catalytic reduction of acid chlorides and/or imidoyl chlorides. The methods comprise reacting the acid chloride or imidoyl chloride with a silane reducing agent in the presence of a catalyst such as [Cp(Pri3P)Ru(NCMe)2]+[PF6]?.
- -
-
Paragraph 0122
(2014/08/19)
-
- Palladium-catalyzed β-acyloxylation of simple amide via sp3 C-H activation
-
β-Acyloxy amides are prepared in moderate to high yields by palladium-catalyzed acyloxylation of primary sp3 C-H bonds from simple amides without any special directing group. A catalytic system of Pd(OAc)2/CF3CO2H/ K2S2O8 is available to various amides with N-substituted by linear alkanes, cyclic alkanes, and electron-deficient benzyl compounds in this reaction. Acyloxylated products could be transformed easily to the corresponding β-hydroxy amides.
- Zhou, Lihong,Lu, Wenjun
-
supporting information
p. 508 - 511
(2014/04/03)
-
- XtalFluor-E, an efficient coupling reagent for amidation of carboxylic acids
-
Amides were produced from carboxylic acids and amines by using XtalFluor-E as an activator. Even poorly reactive carboxylic acids can be transformed to amides. In addition, optically active amines and/or carboxylic acids were not epimerized/racemized during the process.
- Orliac, Aurélie,Gomez Pardo, Domingo,Bombrun, Agnès,Cossy, Janine
-
supporting information
p. 902 - 905
(2013/03/29)
-
- Direct synthesis of amides from carboxylic acids and amines using B(OCH2CF3)3
-
B(OCH2CF3)3, prepared from readily available B2O3 and 2,2,2-trifluoroethanol, is as an effective reagent for the direct amidation of a variety of carboxylic acids with a broad range of amines. In most cases, the amide products can be purified by a simple filtration procedure using commercially available resins, with no need for aqueous workup or chromatography. The amidation of N-protected amino acids with both primary and secondary amines proceeds effectively, with very low levels of racemization. B(OCH2CF3)3 can also be used for the formylation of a range of amines in good to excellent yield, via transamidation of dimethylformamide.
- Lanigan, Rachel M.,Starkov, Pavel,Sheppard, Tom D.
-
p. 4512 - 4523
(2013/06/05)
-
- Taking the F out of FLP: Simple lewis acid-base pairs for mild reductions with neutral boranes via borenium ion catalysis
-
Discrete three-coordinate borenium salts 1c and 1d are accessed by cooperative Lewis acid-base pair-mediated heterolytic splitting of the B-H bond in pinacolborane by B(C6F5)3DABCO and Ph 3C+/DABCO, respectively. The resulting salts are competent catalysts in the reduction of a broad range of imines and can be generated in situ. Moreover, a mechanistic framework for borenium catalysis based on experimental evidence is proposed. The reaction is suggested to proceed by borenium activation of the imine substrate followed by counterintuitive hydride delivery from HBPin (with the assistance of DABCO) rather than from the HB(C6F5)3- anion, contrary to typical mechanisms of reduction in FLP systems.
- Eisenberger, Patrick,Bailey, Adrian M.,Crudden, Cathleen M.
-
supporting information
p. 17384 - 17387
(2013/01/15)
-
- Dehydrogenative amide synthesis: Azide as a nitrogen source
-
A new atom-economical strategy to amide linkage from an azide and alcohol liberating hydrogen and nitrogen was developed with an in situ generated ruthenium catalytic system. The reaction has broad substrate generality including diols for the synthesis of cyclic imides.
- Fu, Zhenqian,Lee, Jeongbin,Kang, Byungjoon,Hong, Soon Hyeok
-
supporting information
p. 6028 - 6031
(2013/02/22)
-
- Phosphine-based redox catalysis in the direct traceless staudinger ligation of carboxylic acids and azides
-
Redox catalysis: Aryl amides, imides, lactams, and dipeptides are obtained through a direct Staudinger ligation mediated by phosphine-based redox catalysis (see scheme). Mechanistic studies indicate the involvement of a phosphonium carboxylate intermediate that leads to a 1,3-acyl migration and thus results in C-N bond formation. Copyright
- Kosal, Andrew D.,Wilson, Erin E.,Ashfeld, Brandon L.
-
supporting information
p. 12036 - 12040
(2013/01/16)
-
- Transamidation of primary amides with amines catalyzed by zirconocene dichloride
-
Zirconocene dichloride (Cp2ZrCl2) has been shown to be an effective catalyst for the transamidation of primary amides with amines in cyclohexane at 80°C in 5-24 hours. For favourable substrates, the reaction can be performed at temperatures as low as 30°C.
- Atkinson, Benjamin N.,Chhatwal, A. Rosie,Lomax, Helen V.,Walton, James W.,Williams, Jonathan M. J.
-
supporting information
p. 11626 - 11628,3
(2012/12/12)
-
- Transamidation of primary amides with amines catalyzed by zirconocene dichloride
-
Zirconocene dichloride (Cp2ZrCl2) has been shown to be an effective catalyst for the transamidation of primary amides with amines in cyclohexane at 80°C in 5-24 hours. For favourable substrates, the reaction can be performed at temperatures as low as 30°C.
- Atkinson, Benjamin N.,Chhatwal, A. Rosie,Lomax, Helen V.,Walton, James W.,Williams, Jonathan M. J.
-
supporting information
p. 11626 - 11628
(2013/01/15)
-
- N -acyl DBN tetraphenylborate salts as N -acylating agents
-
Air-stable and crystalline N-acyl DBN tetraphenylborate salts have been synthesized from 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) and the corresponding acyl chloride in the presence of sodium tetraphenylborate. The salts have been shown to be effective N-acylating agents, reacting with primary amines, secondary amines, and sulfonamides to form the corresponding N-acylated products in good yields. The DBN hydrotetraphenylborate byproduct can be conveniently removed by filtration, providing pure N-acylated products without the need for further purification. The N-acyl DBN tetraphenylborate salts are attractive alternatives to acyl halides as they can be stored in air without decomposition, avoid the production of free acid during acylation reactions, and can be used under more forcing thermal conditions.
- Taylor, James E.,Jones, Matthew D.,Williams, Jonathan M. J.,Bull, Steven D.
-
experimental part
p. 2808 - 2818
(2012/04/23)
-
- An efficient protocol for the amidation of carboxylic acids promoted by trimethyl phosphite and iodine
-
A practical, one-pot protocol is described for the conversion of carboxylic acids into amides through carboxyl activation by the reagent combination of trimethyl phosphite and iodine. This method integrates several advantages: (1) it allows amines to be chemoselectively acylated with excellent results in the presence of sulfur and oxygen nucleophiles; (2) the method shows wide generality in respect of solvent, base, and substrate; (3) the reagents used are widely available and much less expensive than common coupling reagents, and (4) the process is remarkably convenient, permitting extraction, recrystallization, and column chromatography as optional work-up procedures. The chemoselectivity and generality of the method, the low cost, and wide availability of reagents combined with the ease of use make it a very favorable process.
- Luo, Qun-Li,Lv, Lina,Li, Yu,Tan, Jian-Ping,Nan, Wenhui,Hui, Qun
-
supporting information; experimental part
p. 6916 - 6922
(2012/01/06)
-
- Borate esters as convenient reagents for direct amidation of carboxylic acids and transamidation of primary amides
-
Simple borates serve as effective promoters for amide bond formation with a variety of carboxylic acids and amines. With trimethyl or tris(2,2,2- trifluoroethyl) borate, amides are obtained in good to excellent yield and high purity after a simple work-up procedure. Tris(2,2,2-trifluoroethyl) borate can also be used for the straightforward conversion of primary amides to secondary amides via transamidation. The Royal Society of Chemistry 2011.
- Starkov, Pavel,Sheppard, Tom D.
-
supporting information; experimental part
p. 1320 - 1323
(2011/04/23)
-
- Highly regioselective carbonylation of unactivated C(sp3)-H bonds by ruthenium carbonyl
-
The regioselective carbonylation of unactivated C(sp3)-H bonds of aliphatic amides was achieved using Ru3(CO)12 as a catalyst. The presence of a 2-pyridinylmethylamine moiety in the amide is crucial for a successful reaction. The reaction shows a preference for C-H bonds of methyl groups as opposed to methylene C-H bonds and tolerates a variety of functional groups. The stoichiometric reaction of an amide with Ru 3(CO)12 gave a dinuclear ruthenium complex in which the 2-pyridinylmethylamino moiety was coordinated to the ruthenium center in an N,N manner.
- Hasegawa, Nao,Charra, Valentine,Inoue, Satoshi,Fukumoto, Yoshiya,Chatani, Naoto
-
supporting information; experimental part
p. 8070 - 8073
(2011/07/08)
-
- Palladium(II) acetate as catalyst for the N-alkylation of aromatic amines, sulfonamides, and related nitrogenated compounds with alcohols by a hydrogen autotransfer process
-
Palladium(II) acetate is a versatile, inexpensive, and simple catalyst for the selective N-monoalkylation of amino derivatives with poor nucleophilic character, such as aromatic and heteroaromatic amines as well as carboxamides, sulfonamides, and phosphazenes, using, in all cases, primary alcohols as the initial source of the electrophile, through a hydrogen autotransfer process. The regioselectivity of the benzothiazol-2-amine alkylation is contrary to that found using halogenated electrophiles.
- Martinez-Asencio, Ana,Yus, Miguel,Ramon, Diego J.
-
experimental part
p. 3730 - 3740
(2011/12/21)
-
- Cross-coupling of mesylated phenol derivatives with potassium ammonio-and amidomethyltrifluoroborates
-
A large array of aryl and heteroaryl mesylates have been successfully employed as electrophiles in a Csp2-Csp3 Suzuki-Miyaura cross-coupling with potassium ammonio-and amidomethyltrifluoroborates to afford the corresponding products
- Molander, Gary A.,Beaumard, Floriane
-
supporting information; experimental part
p. 1242 - 1245
(2011/05/03)
-
- PROCESS OF FORMING AN AMIDE
-
A process is provided for the synthesis of an amide. A primary or secondary amine and a primary alcohol, with the amine and the alcohol being either moieties of different reactants or moieties of the same molecule, are contacted in the presence of a Ruthenium (II) catalyst. The Ruthenium (II) catalyst is free of a phosphine ligand. The process is also carried out in the absence of a phosphine. Providing the Ruthenium (II) catalyst includes providing an N-heterocyclic carbene.
- -
-
Page/Page column 20-23; 25
(2011/04/19)
-
- Nucleophilic acyl substitution via aromatic cation activation of carboxylic acids: Rapid generation of acid chlorides under mild conditions
-
The first example of aromatic cation-activated nucleophilic acyl substitution has been achieved. The conversion of carboxylic acids to their corresponding acid chlorides occurs rapidly in the presence of 3,3-dichlorocyclopropenes via the intermediacy of cyclopropenium carboxylate complexes. The effect of cyclopropene substituents on the rate of conversion is examined. The addition of tertiary amine base is found to dramatically accelerate reaction, and conditions were developed for the preparation of acid sensitive acid chlorides. Preparative scale peptide couplings of two N-Boc amino acids were achieved with this method.
- Hardee, David J.,Kovalchuke, Lyudmila,Lambert, Tristan H.
-
supporting information; experimental part
p. 5002 - 5003
(2010/06/13)
-
- Direct reaction of aryl iodides with activated aluminium powder and reactions of the derived aryl sesquiiodides
-
High temperature (110-120 °C) direct reaction of ArI (Ar = Ph, 1-C 10H7, 3-Tol) with aluminium powder in the presence of HgCl2 (1 mol%) or liquid gallium metal (10mol%) leads to quantitative conversion to the aryl sesquiiodides Al2Ar3I3. The latter, highly Lewis acidic, compounds are effective in opening of cyclic ethers and direct ester to amide conversions. Georg Thieme Verlag Stuttgart.
- Tang, Xiaoping,Rawson, Daniel,Woodward, Simon
-
experimental part
p. 636 - 638
(2010/09/18)
-
- Direct amide synthesis from either alcohols or aldehydes with amines: Activity of Ru(II) hydride and Ru(0) complexes
-
An in situ generated catalyst from readily available RuH 2(PPh3)4, an N-heterocyclic carbene (NHC) precursor, NaH, and acetonitrile was developed. The catalyst showed high activity for the amide synthesis directly from either alcohols or aldehydes with amines. When a mixture of an alcohol and an aldehyde was reacted with an amine, both of the corresponding amides were obtained with good yields. Homogeneous Ru(0) complexes such as (4-1,5-cyclooctadiene)(6-1,3,5- cyclooctatriene)ruthenium [Ru(cod)(cot)] and Ru3(CO)12 were also active in the amidation of an alcohol or an aldehyde with the help of an in situ generated NHC ligand.
- Muthaiah, Senthilkumar,Ghosh, Subhash Chandra,Jee, Joo-Eun,Chen, Cheng,Zhang, Jian,Hong, Soon Hyeok
-
experimental part
p. 3002 - 3006
(2010/07/05)
-