99-15-0Relevant articles and documents
Minisci-Type Alkylation of N-Heteroarenes by N-(Acyloxy)phthalimide Esters Mediated by a Hantzsch Ester and Blue LED Light
Kyne, Sara Helen,Li, Jiacheng,Siang Tan, Suan,Wai Hong Chan, Philip
supporting information, (2022/01/11)
A synthetic method that enables the Hantzsch ester-mediated Minisci-type C2-alkylation of quinolines, isoquinolines and pyridines by N-(acyloxy)phthalimide esters (NHPI) under blue LED (light emitting diode) light (456 nm) is described. Achieved under mild reaction conditions at room temperature, the metal-free synthetic protocol was shown to be applicable to primary, secondary and tertiary NHPIs to give the alkylated N-heterocyclic products in yields of 21–99%. On introducing a chiral phosphoric acid, an asymmetric version of the reaction was also realised and provided product enantiomeric excess (ee) values of 53–99%. The reaction mechanism was delineated to involve excitation of an electron-donor acceptor (EDA) complex, formed from weak electrostatic interactions between the Hantzsch ester and NHPI, which generates the posited radical species of the redox active ester that undergoes addition to the N-heterocycle.
Reactivity of α-Amino Acids in the Reaction with Esters in Aqueous–1,4-Dioxane Media
Kochetova,Kustova,Kuritsyn
, p. 80 - 85 (2018/03/09)
The kinetics of the reaction of a series of α-amino acids with 4-nitrophenyl acetate, 4-nitrophenyl benzoate, and 2,4,6-trinitrophenyl benzoate in aqueous 1,4-dioxane medium has been studied. Kinetics of the reactions involving 4-nitrophenyl acetate and 2,4,6-trinitrophenyl benzoate has complied with the Br?nsted dependence and revealed linear correlation between rate constant logarithm and the energy difference of the frontier orbitals of α-amino acids anions.
Regioselective synthesis of tetrasubstituted pyrroles by 1,3-dipolar cycloaddition and spontaneous decarboxylation
Kim, Yongju,Kim, Jonghoon,Park, Seung Bum
supporting information; experimental part, p. 17 - 20 (2009/08/07)
We developed a novel regioselective synthesis of tetrasubstituted pyrroles via the classic 1,3-dipolar cycloaddition of α,β-unsaturated benzofuran-3(2H)-one and azlactones (1) followed by spontaneous decarboxylation. The complete regiochemical control of tetrasubstituted pyrroles was confirmed by the orthogonal synthesis of complementary regioisomers (7a and 7b) simply by using different azlactones (1a and 1b, respectively).
Microwave-assisted synthesis of amide under solvent-free conditions
Wang, Xiao-Jian,Yang, Qian,Liu, Fei,You, Qi-Dong
, p. 1028 - 1035 (2008/09/18)
An efficient and environmentally friendly synthetic method for the synthesis of primary amides under microwave irradiation was described, in which the primary amine was directly reacted with acid without any catalytic agents. The reaction took place in 8-12-min, which was much shorter than the traditional synthetic methods, with almost quantitative yields. The influential factor of the reaction was discussed. The tautomerization between the carboxylic acid group and the H atom in α-carbon of L-amino acid was observed, presumably a dehydrated intermediate forming from this tautomerized isomer. Copyright Taylor & Francis Group, LLC.
A study of amidocarbonylation reactions catalyzed by Pd/HZSM-5
Ke, Wu Yang,Xuan, Zhen Jiang
, p. 806 - 809 (2007/10/03)
A HZSM-5-supported palladium catalyst, which was prepared by the conventional impregnation method, was utilized in amidocarbonylation reactions. Several important parameters were optimized to give moderate to excellent yields. The catalyst recycling of Pd/HZSM-5, for the first time, was achieved for at least four run times without depreciation of catalytic activity. The studies of TEM images revealed that agglomeration of the palladium species of Pd/ HZSM-5 catalyst was avoided after reaction, which was quite different from the case of Pd/C catalyst.
Palladium-catalyzed amidocarbonylation improved by recyclable ionic liquids
Zhu, Bingchun,Jiang, Xuanzhen
, p. 2795 - 2798 (2008/02/11)
Two types of ionic liquids (halide anion ionic liquids and Brensted acidic ionic liquids) were first applied to improve the palladium-catalyzed amidocarbonylation. Both the palladium catalyst and the ionic liquids could be recycled at least five times without significant loss in catalytic activity. Georg Thieme Verlag Stuttgart.
METHOD OF AMIDOCARBONYLATION REACTION
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Page/Page column 11, (2008/06/13)
A novel method of an amidocarbonylation reaction among an aldehyde compound, an amide compound, and carbon monoxide, which comprises using a palladium-supporting crosslinked-polymer composition containing palladium clusters having a major-axis length of 20 nm or shorter to conduct the amidocarbonylation reaction. Thus, an N-acyl-±-amino acid can be more efficiently and selectively synthesized in a clean reaction system. Also provided is a catalyst for use in the method.
Platinum-catalyzed amidocarbonylation
Sagae, Takahiro,Sugiura, Masaharu,Hagio, Hiroyuki,Kobayashi, Shu
, p. 160 - 161 (2007/10/03)
The first example of platinum-catalyzed amidocarbonylation of aldehydes with amides and carbon monoxide is described. In contrast to precedent palladium catalysis, a remarkable ligand acceleration by phosphines was observed. Furthermore, an optically active N-acetyl amino acid was partially epimerized under the platinum-catalyzed conditions, while faster racemization was observed under the palladium catalysis.
Rhodium-catalysed racemisation of N-acyl α-amino acids
Hateley, Martin J.,Schichl, Daniel A.,Kreuzfeld, Hans-J?rn,Beller, Matthias
, p. 3821 - 3824 (2007/10/03)
The first transition metal-catalysed racemisation of N-acyl α-amino acids, which is of importance for kinetic resolution processes, is described. Enantiomerically pure N-acyl α-amino acids were efficiently racemised under mild conditions using various rhodium complexes as catalysts, e.g. [Rh(cod)Cl]2, in the presence of phosphines. (C) 2000 Elsevier Science Ltd.
A new improved palladium-catalyzed amidocarbonylation
Beller, Matthias,Moradi, Wahed A.,Eckert, Markus,Neumann, Helfried
, p. 4523 - 4526 (2007/10/03)
A new and improved variant of the palladium-catalyzed amidocarbonylation to yield N-acyl-α-amino acids is described. Using Pd/C as catalyst the products were prepared in good to excellent yields (up to 98 %). Advantages of the Pd/C-catalyst with regard to former catalyst systems are demonstrated by the preparation of N-substituted non-natural amino acids which are of current interest as structural units of peptoids.
