- Chemoselective N-acetylation of primary aliphatic amines promoted by pivalic or acetic acid using ethyl acetate as an acetyl donor
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The combination of pivalic or acetic acid as a promoter and EtOAc as a solvent and acetyl donor proved to be efficient for the chemoselective N-acetylation of primary aliphatic amines to afford the corresponding acetamides. We developed a simple and convenient approach, which requires mild reaction conditions. Competitive inter- and intramolecular reactions between aliphatic amines, alcohols, and aromatic amines were examined, and chemoselectivity was achieved by adjusting the conditions of the reaction.
- Yoshida, Tomoki,Kawamura, Shimpei,Nakata, Kenya
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supporting information
p. 1181 - 1184
(2017/03/02)
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- Chemoselective N-deacetylation under mild conditions
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A mild and efficient chemoselective N-deacetylation using the Schwartz reagent at room temperature in rapid time is described. The mild and neutral conditions enable orthogonal N-deacetylation in the presence of some of the common protecting groups (viz. Boc, Fmoc, Cbz, Ts). The deprotection conditions did not induce any epimerization at the chiral amino centre.
- Sultane, Prakash R.,Mete, Trimbak B.,Bhat, Ramakrishna G.
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supporting information
p. 261 - 264
(2014/01/06)
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- Isopropenyl acetate, a remarkable, cheap and acylating agent of amines under solvent- and catalyst-free conditions: A systematic investigation
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Isopropenyl acetate was proved to be an efficient reagent for acetylation of amine in the absence of solvent and catalyst. The corresponding acetamides were obtained in very high yields without any purification.
- Pelagalli, Romina,Chiarotto, Isabella,Feroci, Marta,Vecchio, Stefano
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supporting information; experimental part
p. 2251 - 2255
(2012/09/08)
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- Syntheses of chiral β- And γ-amino ethers, morpholines, and their homologues via nucleophilic ring-opening of chiral activated aziridines and azetidines
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Figure Persented: Lewis acid catalyzed quaternary ammonium salt mediated highly regioselective ring-opening of chiral activated aziridines and azetidines with alcohols to nonracemic β- and γ-amino ethers has been developed. The reaction mainly proceeds vi
- Ghorai, Manas K.,Shukla, Dipti,Bhattacharyya, Aditya
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p. 3740 - 3753
(2012/06/18)
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- MUSCARINIC AGONISTS
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The present invention relates to compounds of Formula (I): which are agonists of the M-1 muscarinic receptor.
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- Highly potent inhibitors of TNF-α production. Part I: Discovery of new chemical leads and their structure-activity relationships
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Discovery of new chemical leads of inhibitors for TNF-α production starting from the chemical modification of 1 is reported. Further biological studies of 1 to disclose the site of its action strongly suggested that 1 inhibits LPS-induced TNF-α expression
- Matsui, Toshiaki,Kondo, Takashi,Nishita, Yoshitaka,Itadani, Satoshi,Nakatani, Shingo,Omawari, Nagashige,Sakai, Masaru,Nakazawa, Shuichi,Ogata, Akihito,Mori, Hideaki,Terai, Kouichiro,Kamoshima, Wataru,Ohno, Hiroyuki,Obata, Takaaki,Nakai, Hisao,Toda, Masaaki
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p. 3757 - 3786
(2007/10/03)
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- (DIETHYLAMINO)SULFUR TRIFLUORIDE (DAST) AS A USEFUL REAGENT FOR THE PREPARATION OF 2-OXAZOLINES FROM 1,2-AMIDO ALCOHOLS
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Acylic 1,2-amido alcohols (6) react efficiently with a slight excess of (diethylamino)sulfur trifluoride (DAST) to afford the corresponding 2-oxazolines (10) in good yields ranging between 57-95percent.Even at the low temperature of -78 deg C, a rapid ( 1 h) and stereoselective amide cyclization is observed without formation of acylaziridine by-products.The scope of this cyclization is discussed.
- Lafargue, Pierre,Guenot, Pierre,Lellouche, Jean-Paul
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p. 947 - 958
(2007/10/02)
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- Stereoselective Aldol Reaction with Chiral Secondary Acetamides
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The deprotonated acetamides 4a - c and 5a - c are added to prochiral carbonyl compounds.The influence of the solvent, of the reaction temperature, and of the enolate gegenion on the ratio of the isomeric products 8/9, 18/19, and 26/27, respectively, are studied.The highest degree of diastereoselectivity are observed, when the titanium enolate of the acetamide 4a or the threefold deprotonated N-acetyl-α-phenylglycinol (5a) is used.The diastereomers 18a - d, formed in excess in the addition of 5a to aldehydes, are isolated in pure from by a single recrystallization, and afford the enantiomerically pure β-hydroxy carboxylic acids 3a - d.Thereby, the chiral auxiliary, α-phenylglycinol (14), is recovered.
- Devant, Ralf,Braun, Manfred
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p. 2191 - 2207
(2007/10/02)
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- On Amino Acid Antagonists,IV.-Separation and Determination of the Configurations of the Stereoisomeric N-Acetyl-2-(2'-cyclohexenyl)glycines
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The D-(+)-(1-phenylethyl)amides 5 as well as the D-(-)-O-acetyl-α-phenylglycinolamides 7 of the title compounds were separated on silica gel into the four diastereomeric compounds.All attempts failed to hydrolyze 5 and 7 to the corresponding acids.In contrast the diastereomeric D-(-)-N-acetyl-α-phenylglycinol esters 10 which were separated on silica gel were hydrolysed to the optically active acids 3a-d.The absolute configurations at C-2 in 3 were determined by correlation with the saturated glycine derivatives of known stereochemistry.The relative configurationsand hence the absolute configurations at C-1' in 3a-d were deduced from the NMR- and CD-spectra and were confirmed by X-ray analysis of 3a.Only the amino acid 3b with the (2S,1'R)-configuration exhibits biological activity.
- Santoso, Sentot,Kemmer, Thorsten,Trowitzsch, Wolfram
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p. 642 - 657
(2007/10/02)
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