1119-49-9Relevant articles and documents
Cyclic guanidine organic catalysts: What is magic about triazabicyclodecene?
Kiesewetter, Matthew K.,Scholten, Marc D.,Kirn, Nicole,Weber, Ryan L.,Hedrick, James L.,Waymouth, Robert M.
, p. 9490 - 9496 (2009)
(Chemical Equation Presented) The bicyclic guanidine 1,5,7- triazabicyclo[4.4.0]dec-5-ene (TBD) is an effective organocatalyst for the formation of amides from esters and primary amines. Mechanistic and kinetic investigations support a nucleophilic mechanism where TBD reacts reversibly with esters to generate an acyl-TBD intermediate that acylates amines to generate the amides. Comparative investigations of the analogous bicyclic guanidine 1,4,6-triazabicyclo[3.3.0]oct-4-ene (TBO) reveal it to be a much less active acylation catalyst than TBD. Theoretical and mechanistic studies imply that the higher reactivity of TBD is a consequence of both its higher basicity and nucleophilicity than TBO as well as the high reactivity of the acyl-TBD intermediate, which is sterically prevented from adopting a planar amide structure.
Lower primary alkanols and their esters in a Ritter-type reaction with nitriles. An efficient method for obtaining N-primary-alkyl amides
Lebedev, Mikhail Y.,Erman, Mark B.
, p. 1397 - 1399 (2002)
N-Primary-alkyl amides RCONHR1 were obtained by a Ritter-type reaction of nitriles RCN with lower primary alkanols R1OH or their esters in the presence of acids.
Nucleophilic substitution in carboxylic esters in oil-in-water microemulsions
Mirgorodskaya,Kudryavtseva
, p. 1261 - 1265 (2002)
In hydrolysis and aminolysis of p-nitrophenyl esters of carboxylic acids in oil-in-water microemulsions on the basis of surfactants of various nature, a complex mechanism of the effect of the medium is operative, including shift of acid-base equilibria in the nucleophile. The rate constants of the processes studied are quantitatively related to the surface potential of the microdroplet. Varied hydrophobicity of the nucleophile and substrate changes the site of the reaction act and the relative contributions of aminolysis and hydrolysis.
The Amidation of Carboxylic Acid with Amine over Hydrous Zirconium(IV) Oxide
Takahashi, Kyoko,Shibagaki, Makoto,Kuno, Hideyuki,Kawakami, Hiroshi,Matsushita, Hajime
, p. 1333 - 1334 (1989)
The reaction of a carboxylic acid or an ester with an amine to give the corresponding amide was carried out efficiently over hydrous zirconium(IV) oxide, whether in the vapor phase or in the liquid phase.
Kinetic Analysis of Ester Aminolysis Catalyzed by Nucleosides in a Nonpolar Medium. Evidence of Bifunctional Catalysis
Melander, Christian,Horne, David A.
, p. 9295 - 9297 (1997)
Kinetic analysis of ester aminolysis in benzene catalyzed by 2′,3′,5′-O-tris(tert-butyldimethylsilyl)-protected nucleosides and 2-pyridone is reported. The catalytic rate constant k3′ was determined for protected nucleosides A, C, G, U, and pseudouridine (Ψ). The relatively high value associated with C and 2-pyridone is indicative of bifunctional catalysis occurring through stabilization of the aminolysis transition state. The implications of this finding on the possible role C plays in biological catalysis during protein synthesis is hypothesized. ? Abstract published in Advance ACS Abstracts, December 1, 1997.
The mechanism of photoinduced acylation of amines by N-acyl-5,7- dinitroindoline as determined by time-resolved infrared spectroscopy
Cohen, Andrew D.,Helgen, Celine,Bochet, Christian G.,Toscano, John P.
, p. 2845 - 2848 (2005)
(Chemical Equation Presented) The photochemistry of N-acyl-5,7- dinitroindoline (1) was studied in acetonitrile using nanosecond time-resolved infrared (TRIR) spectroscopy. Upon photolysis, two nearly but not completely overlapping sets of transient IR ba
Pivotal role of intramolecular catalysis in the selective acetylation of alkyl amines
Nishida, Elvis N.,Vitto, Ramon,Peixoto, R?mulo C.R.,Nome, Faruk,Souza, Bruno S.
, (2018)
Preparation of amides by the use of esters as the "acyl donor" is less explored because they are less reactive and usually more steric demanding than conventional acid halides and anhydrides. Here, we report that 3-acetoxy-2-naphthoic acid, an aspirin analogue, can be used as a mild amine acetylating agent in ethanol at 25°C. The reaction is sensitive to steric and polar effects of the attacking amine, and the rate constants can be appropriately fitted by the Pavelich-Taft correlation. Density functional theory calculations used to study all reaction steps indicate that the o-carboxy group plays a pivotal role, guiding the attacking amine and accelerating the reaction. The reaction can be conveniently used for the acylation of a variety of primary and secondary amines.
Structure-reactivity correlation in the aminolysis of 4-fluorophenyl acetate in aqueous medium
Rajarathnam,Jeyakumar,Ananthakrishna Nadar
, p. 366 - 373 (2002)
The reaction of the title substrate with a series of amines of varying pKa, viz. ammonia, ethanolamine, glycine, 1,2-diaminopropane, 1,3-diaminopropane, n-butylamine, piperidine, hydrazine, imidazole, and hydroxylamine is subjected to a kinetic study in aqueous medium, 25°C, ionic strength 0.1 M (KCl). Pseudo-first-order rate coefficients (kobs) are found throughout under amine excess at various pH values for each amine. For amines, excluding hydrazine, ammonia, and hydroxylamine the reaction follows clean second-order kinetics and the plots of (kobs - kH) against free amine concentration are linear at constant pH. The macroscopic nucleophilic substitution rate coefficients (kN) are obtained as the slopes of these plots and found to be pH independent. For hydrazine, ammonia, and hydroxylamine, a rate dependence on more than first power of the amine is observed, accordingly, the rate constants for the assisted paths have been disseminated for these amines besides kN. The Broensted-type plot (logkN against amine pKa) is linear with a slope value of β = 1.02. The magnitude of the slope value is consistent with a stepwise mechanism through a zwitterionic tetrahedral addition intermediate whose breakdown to products is rate-determining (k2 step). A remarkable reactivity difference is observed among the diamines, the reason for which is discussed in detail.
Acylmethanesulfonamides as new acylating agents for primary amines
Coniglio, Silvia,Aramini, Andrea,Cesta, M. Candida,Colagioia, Sandro,Curti, Roberto,D'Alessandro, Fabrizio,D'Anniballe, Gaetano,D'Elia, Valerio,Nano, Giuseppe,Orlando, Valerie,Allegretti, Marcello
, p. 5375 - 5378 (2004)
A new, simple and efficient procedure for the preparation of secondary amides through internal condensation of acylmethanesulfonamides ammonium salts is described. The selective acylation of mixed primary-secondary amines could be an attractive application of the new method.
A CO2-Catalyzed Transamidation Reaction
Yang, Yang,Liu, Jian,Kamounah, Fadhil S.,Ciancaleoni, Gianluca,Lee, Ji-Woong
, p. 16867 - 16881 (2021/11/18)
Transamidation reactions are often mediated by reactive substrates in the presence of overstoichiometric activating reagents and/or transition metal catalysts. Here we report the use of CO2as a traceless catalyst: in the presence of catalytic amounts of CO2, transamidation reactions were accelerated with primary, secondary, and tertiary amide donors. Various amine nucleophiles including amino acid derivatives were tolerated, showcasing the utility of transamidation in peptide modification and polymer degradation (e.g., Nylon-6,6). In particular,N,O-dimethylhydroxyl amides (Weinreb amides) displayed a distinct reactivity in the CO2-catalyzed transamidation versus a N2atmosphere. Comparative Hammett studies and kinetic analysis were conducted to elucidate the catalytic activation mechanism of molecular CO2, which was supported by DFT calculations. We attributed the positive effect of CO2in the transamidation reaction to the stabilization of tetrahedral intermediates by covalent binding to the electrophilic CO2
