- Ammonia-borane as a Catalyst for the Direct Amidation of Carboxylic Acids
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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.
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supporting information
p. 2938 - 2942
(2021/05/04)
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- Direct amidation of non-activated carboxylic acid and amine derivatives catalyzed by TiCp2Cl2
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This paper described a mild and efficient direct amidation of non-activated carboxylic acid and amine derivatives catalyzed by TiCp2Cl2. Arylacetic acid derivatives reacted with different amines to afford the corresponding amides in good to excellent yield except of aniline. Aryl formic acids failed to react with aniline but smoothly reacted with aliphatic amines and benzylamine in moderate to good yield, fatty acids reacting with benzyl and aliphatic amines give amides in good to excellent yield. Chiral amino acids derivatives were transformed into amides without racemization in moderate yield. The possible mechanism of direct amidation catalyzed by TiCp2Cl2 was discussed. This catalytic method is very suitable for the amidation of low sterically hindered arylacetic acid, fatty acids with different low sterically hindered amines except aniline, as well as the amidation of aryl formic acid with benzyl and aliphatic amines.
- Wang, Hui,Dong, Wei,Hou, Zhipeng,Cheng, Lidan,Li, Xiufen,Huang, Longjiang
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- Solvent-free iron(III) chloride-catalyzed direct amidation of esters
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Amide functional groups are prominent in a broad range of organic compounds with diverse beneficial applications. In this work, we report the synthesis of these functional groups via an iron(iii) chloride-catalyzed direct amidation of esters. The reactions are conducted under solvent-free conditions and found to be compatible with a range of amine and ester substrates generating the desired amides in short reaction times and good to excellent yields at a catalyst loading of 15 mol%.
- Mkhonazi, Blessing D.,Shandu, Malibongwe,Tshinavhe, Ronewa,Simelane, Sandile B.,Moshapo, Paseka T.
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supporting information
(2020/03/17)
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- Direct amide coupling of non-activated carboxylic acids and amines catalysed by zirconium(IV) chloride
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Amidst the green: A green, mild and effective protocol for the direct formation of secondary and tertiary amides from non-activated carboxylic acids and amines in good to excellent yields by employing ZrCl4 as the catalyst is presented (see scheme). The amide coupling protocol proved to be suitable for scaled up syntheses, and the mild reaction conditions conserve the enantiopurity of chiral starting materials. Copyright
- Lundberg, Helena,Tinnis, Fredrik,Adolfsson, Hans
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supporting information; experimental part
p. 3822 - 3826
(2012/05/20)
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- Titanium(IV) isopropoxide as an efficient catalyst for direct amidation of nonactivated carboxylic acids
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Secondary and tertiary amides are formed in high yields, in an efficient and environmentally benign titanium(IV) isopropoxide catalyzed direct amidation of carboxylic acids with primary and secondary amines. Georg Thieme Verlag Stuttgart ? New York.
- Lundberg, Helena,Tinnis, Fredrik,Adolfsson, Hans
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supporting information
p. 2201 - 2204
(2012/10/30)
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- Solvent-free protocol for amide bond formation via trapping of nascent phosphazenes with carboxylic acids
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A solvent-free synthesis of amides via the coupling of phosphazenes with carboxylic acids is reported. Increasing the rate of heating either by microwave irradiation or conventional heating results in multifold increase in the rate of amide bond formation. Synthesis of a library of amides including a potent antitumour candidate has been accomplished.
- Sathishkumar, Murugan,Shanmugavelan, Poovan,Nagarajan, Sangaraiah,Maheswari, Murugesan,Dinesh, Murugan,Ponnuswamy, Alagusundaram
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supporting information; experimental part
p. 2830 - 2833
(2011/06/23)
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- Silica gel-mediated amide bond formation: An environmentally benign method for liquid-phase synthesis and cytotoxic activities of amides
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An efficient, functional group tolerable, and environmentally benign process for the synthesis of amides was developed. No activation reagents or scavengers are required in this process. Purification of desired compounds is easy, rapid, and cost-effective. This protocol provides an alternative for the combinatorial liquid-phase synthesis of amide libraries for drug discovery. By this method, a number of amides were prepared and evaluated in vitro against a panel of human tumor cell lines. Cinnamic amide IV-4 was found to be the most potent compound synthesized against four human tumor cell lines.
- Yang, Xiao-Dong,Zeng, Xiang-Hui,Zhao, Yuan-Hong,Wang, Xue-Quan,Pan, Zhi-Qiang,Li, Liang,Zhang, Hong-Bin
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scheme or table
p. 307 - 310
(2010/11/18)
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- Oxyacetamide compounds useful for stimulating or inducing the growth and/or retarding the loss of keratin fibers
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Oxyacetamide compounds that are inhibitors of type-1 15-hydroxyprostaglandin dehydrogenase (15-PGDH) and which have the formula (I), or salts and/or solvates thereof: are useful for inducing and/or stimulating the growth of human keratin fibers, e.g., human head hair and/or eyelashes, and/or for retarding the loss and/or increasing the density thereof and/or for caring for and/or making up such keratin fibers.
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Page/Page column 18
(2008/06/13)
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- PS-IIDQ: a supported coupling reagent for efficient and general amide bond formation
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Polystyrene-IIDQ, a polymer-supported coupling reagent, was synthesized in three steps from Merrifield resin in 86% overall conversion. This reagent efficiently coupled carboxylic acids to amines in good yields and high purities, required no pre-activation step, and was tolerant of the order of reagent addition. PS-IIDQ was observed to be more efficient than polymer-supported carbodiimides (PS-EDC and PS-DCC) and gave higher yields than HATU for general amide bond formation, including the coupling of anilines and hindered substrates. When evaluated with five carboxylic acids and nine amines (including anilines and secondary amines) PS-IIDQ gave an average isolated yield of 73%.
- Valeur, Eric,Bradley, Mark
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p. 8855 - 8871
(2008/02/11)
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- USE OF-OXYACETAMIDE COMPOUNDS FOR PROMOTING AND/OR INDUCING AND/OR STIMULATING THE PIGMENTATION OF KERATIN MATERIALS AND/OR FOR LIMITING THEIR DEPIGMENTATION AND/OR BLEACHING
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The present invention relates to the cosmetic use of at least one 2-oxyacetamide compound of formula (I) below, or a salt and/or solvate thereof, as an agent for promoting and/or inducing and/or stimulating the pigmentation of keratin materials and/or as an agent for preventing and/or limiting the depigmentation and/or bleaching of keratin materials and more particularly of human keratin fibres such as the hair, beard hair, moustache hair, the eyelashes and the eyebrows . The present invention more particularly relates to the cosmetic use of at least one 2-oxyacetamide compound of formula (I) , or a salt and/or solvate thereof , as an agent for preventing and/or limiting the canities of the said human keratin fibres.
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Page/Page column 45
(2010/11/25)
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- Synthesis of nitrogen-containing phenoxyacetic acid derivatives
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Nitrogen-containing phenoxyacetic acid derivatives were synthesized by reactions of substituted phenoxyacetic acids with amines, urea, and ethyl carbamate.
- Yamansarova,Kukovinets,Zainullin,Galin,Abdullin
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p. 546 - 550
(2007/10/03)
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- Facile stereoselective synthesis of 1,3-disubstituted-4-trichloromethyl azetidin-2-ones
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The highly stereoselective synthesis of 1,3-disubstituted-4-trichloromethyl azetidin-2-ones by the [2+2] cycloaddition of ketenes with imines derived from chloral is described. The highly stereoselective synthesis of 1,3-disubstituted-4-trichloromethyl azetidin-2-ones by the [2+2] cycloaddition of ketenes with imines derived from chloral is described.
- Govande,Deshmukh
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p. 6563 - 6566
(2007/10/03)
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- A novel solid-phase chlorinating reagent for the synthesis of acyl chlorides
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Cyanuric chloride was loaded onto a modified Wang resin, which was successfully used to convert carboxylic acids to their corresponding acyl chlorides. The formation of acyl chlorides were confirmed by condensation with various amines or alcohols to form the corresponding amides or esters.
- Luo, Guanglin,Xu, Li,Poindexter, Graham S.
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p. 8909 - 8912
(2007/10/03)
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- Efficient procedure for the preparation of amides using polymer-bound reagents
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An effective method for the conversion of acids into amides is presented. The two-step procedure includes the preparation of acid chloride intermediates using Pol-Ph3P and subsequent treatment of these intermediates with amines and polymer-bound base. The amides were accessible in high yields and purities without further purification.
- Buchstaller,Ebert,Anlauf
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p. 1001 - 1005
(2007/10/03)
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- Kinetics of Aminolysis of Phenyl Phenoxyacetates with Benzylamines in Acetonitrile
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Kinetic studies are carried out on the reactions of benzylamines with phenyl phenoxyacetates in acetonitrile.Based on (i) the large magnitude of various selectivity parameters, ρx, ρz and ρxz, (ii) the normal kinetic isotope effects (kH/kD > 1.0) involving deuterated benzylamine nucleophiles and (iii) the low entalpies and entropies of activation, it was cocncluded that the reactions proceed by a stepwise mechanism with rate-limiting breakdown of the tetrahedral zwitterionic intermadiate.There are, however, two pathways in the rate-limiting breakdown step of the intermediate, the uncatalysed and base-catalysed.The latter path is characterized by the larger ρxz and kH/kD values, and lower activation parameters than those the uncatalyzed path.
- Koh, Han Joong,Kim, Tae Hyoung,Lee, Bon-Su,Lee, Ikchoon
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p. 2741 - 2751
(2007/10/03)
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- Electrochemical generation and reactions of acyloxytriphenylphosphonium ions
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Constant-current electrolysis, in an undivided cell, of Ph3P in the presence of a carboxylic acid in CH2Cl2 containing 2,6-lutidinium perchlorate as the supporting electrolyte was shown to generate the corresponding acyloxyphosphonium ion, Ph3P+-OCOR, which was converted in situ to esters, amides, and β-lactams under mild conditions.
- Ohmori, Hidenobu,Maeda, Hatsuo,Kikuoka, Masayuki,Maki, Toshihide,Masui, Masaichiro
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p. 767 - 776
(2007/10/02)
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