18494-52-5Relevant articles and documents
IrIII-Catalyzed direct syntheses of amides and esters using nitriles as acid equivalents: A photochemical pathway
Talukdar, Ranadeep
supporting information, p. 5303 - 5308 (2020/04/17)
An unprecedented IrIII[df(CF3)ppy]2(dtbbpy)PF6-catalyzed simple photochemical process for direct addition of amines and alcohols to the relatively less reactive nitrile triple bond is described herein. Various amides and esters are synthesized as the reaction products, with nitriles being the acid equivalents. A mini-library of different types of amides and esters is made using this mild and efficient process, which uses only 1 mol% of photocatalyst under visible light irradiation (λ = 445 nm). The reaction strategy is also efficient for gram-scale synthesis.
Catalytic direct amidations in: Tert -butyl acetate using B(OCH2CF3)3
Coomber, Charlotte E.,Laserna, Victor,Martin, Liam T.,Smith, Peter D.,Hailes, Helen C.,Porter, Michael J.,Sheppard, Tom D.
supporting information, p. 6465 - 6469 (2019/07/09)
Catalytic direct amidation reactions have been the focus of considerable recent research effort, due to the widespread use of amide formation processes in pharmaceutical synthesis. However, the vast majority of catalytic amidations are performed in non-polar solvents (aromatic hydrocarbons, ethers) which are typically undesirable from a sustainability perspective, and are often poor at solubilising polar carboxylic acid and amine substrates. As a consequence, most catalytic amidation protocols are unsuccessful when applied to polar and/or functionalised substrates of the kind commonly used in medicinal chemistry. In this paper we report a practical and useful catalytic direct amidation reaction using tert-butyl acetate as the reaction solvent. The use of an ester solvent offers improvements in terms of safety and sustainability, but also leads to an improved reaction scope with regard to polar substrates and less nucleophilic anilines, both of which are important components of amides used in medicinal chemistry. An amidation reaction was scaled up to 100 mmol and proceeded with excellent yield and efficiency, with a measured process mass intensity of 8.
Cross-Dehydrogenating Coupling of Aldehydes with Amines/R-OTBS Ethers by Visible-Light Photoredox Catalysis: Synthesis of Amides, Esters, and Ureas
Pandey, Ganesh,Koley, Suvajit,Talukdar, Ranadeep,Sahani, Pramod Kumar
supporting information, p. 5861 - 5865 (2018/09/21)
A straightforward synthesis of amides, ureas, and esters is reported by visible-light cross-dehydrogenating coupling (CDC) of aldehydes (or amine carbaldehydes) and amines/R-OTBS ethers by photoredox catalysis. The reaction is found to be general and high yielding. A plausible mechanistic pathway has been proposed for these transformations and is supported by appropriate controlled experiments.
MANGANESE BASED COMPLEXES AND USES THEREOF FOR HOMOGENEOUS CATALYSIS
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, (2017/09/05)
The present invention relates to novel manganese complexes and their use, inter alia, for homogeneous catalysis in (1) the preparation of imine by dehydrogenative coupling of an alcohol and amine; (2) C-C coupling in Michael addition reaction using nitriles as Michael donors; (3) dehydrogenative coupling of alcohols to give esters and hydrogen gas (4) hydrogenation of esters to form alcohols (including hydrogenation of cyclic esters (lactones) or cyclic di-esters (di- lactones), or polyesters); (5) hydrogenation of amides (including cyclic dipeptides, lactams, diamide, polypeptides and polyamides) to alcohols and amines (or diamine); (6) hydrogenation of organic carbonates (including polycarbonates) to alcohols or hydrogenation of carbamates (including polycarbamates) or urea derivatives to alcohols and amines; (7) dehydrogenation of secondary alcohols to ketones; (8) amidation of esters (i.e., synthesis of amides from esters and amines); (9) acylation of alcohols using esters; (10) coupling of alcohols with water and a base to form carboxylic acids; and (11) preparation of amino acids or their salts by coupling of amino alcohols with water and a base. (12) preparation of amides (including formamides, cyclic dipeptides, diamide, lactams, polypeptides and polyamides) by dehydrogenative coupling of alcohols and amines; (13) preparation of imides from diols.
Selective α-Oxyamination and Hydroxylation of Aliphatic Amides
Li, Xinwei,Lin, Fengguirong,Huang, Kaimeng,Wei, Jialiang,Li, Xinyao,Wang, Xiaoyang,Geng, Xiaoyu,Jiao, Ning
supporting information, p. 12307 - 12311 (2017/09/11)
Compared to the α-functionalization of aldehydes, ketones, even esters, the direct α-modification of amides is still a challenge because of the low acidity of α-CH groups. The α-functionalization of N?H (primary and secondary) amides, containing both an unactived α-C?H bond and a competitively active N?H bond, remains elusive. Shown herein is the general and efficient oxidative α-oxyamination and hydroxylation of aliphatic amides including secondary N?H amides. This transition-metal-free chemistry with high chemoselectivity provides an efficient approach to α-hydroxy amides. This oxidative protocol significantly enables the selective functionalization of inert α-C?H bonds with the complete preservation of active N?H bond.
Low-Pressure Radical11C-Aminocarbonylation of Alkyl Iodides through Thermal Initiation
Chow, Shiao Y.,Odell, Luke R.,Eriksson, Jonas
, p. 5980 - 5989 (2016/12/26)
A radical11C-aminocarbonylation protocol characterized by excellent substrate compatibility was developed to transform alkyl iodides into11C-labelled amides, including the 11β-HSD1 inhibitor [carbonyl-11C]adamantan-1-yl(piperidin-1-yl)methanone. This protocol serves as a complementary extension of palladium-mediated11C-aminocarbonylation, which is limited to the preparation of11C-labelled compounds lacking beta-hydrogen atoms. The use of AIBN as a radical initiator and a low-pressure xenon–[11C]CO delivery unit represents a simple and convenient alternative to previous radical11C-carbonylation methodologies burdened with the need for a proprietary high pressure reactor connected to a light source.
Colloid and nano-sized catalysts in organic synthesis: X. Synthesis of carboxamides by direct amidation of carboxylic acids and transamidation catalyzed by colloid copper
Mokhov,Popov, Yu. V.,Budko
, p. 820 - 826 (2015/06/08)
Abstract It was found that in the presence of colloid copper the direct amidation of some carboxylic acids with primary and secondary amines in benzene with azeotropic distillation of water became possible. The catalyst was proven to be suitable also for transamidation reaction of a number of carboxylic acid amides under mild conditions in solvent-free conditions.
Palladium-catalyzed aminocarbonylation of N-chloroamines with boronic acids
Li, Wanfang,Wu, Xiao-Feng
supporting information, p. 7374 - 7378 (2015/05/27)
Abstract Aryl (pseudo)halide-based (C-X) carbonylation reactions have been extensively studied during the past few decades. From both academic and synthetic points of view, the carbonylative transformation of N-X bonds represents an interesting and attractive area of investigation. In light of this, the first carbonylative cross-coupling between N-chloroamines and organoboronic acids has been developed. This new type of aminocarbonylation proceeds at mild temperatures (45-55 °C) with 2 mol % Pd/C (10 wt %) as the ligand-free catalyst. Not only arylboronic acids, but also alkenyl- and alkylboronic acids can be applied as the substrates and bromide and iodide substituents in the substrates are well tolerated. Initial mechanistic investigations have also been performed. Umpolung aminocarbonylation: The first palladium-catalyzed carbonylative cross-coupling between N-chloroamines and organoboronic acids has been realized. Various amides were isolated in moderate to excellent yields from reactions under mild temperatures with ligand-free Pd/C as the catalyst. Not only arylboronic acids, but also alkenyl- and alkylboronic acids are applied as the substrates and bromide and iodide substituents in the substrates are well tolerated.
Synthesis of amides from esters and amines with liberation of H2 under neutral conditions
Gnanaprakasam, Boopathy,Milstein, David
supporting information; experimental part, p. 1682 - 1685 (2011/04/22)
Efficient synthesis of amides directly from esters and amines is achieved under mild, neutral conditions with the liberation of molecular hydrogen. Both primary and secondary amines can be utilized. This unprecedented, general, environmentally benign reaction is homogeneously catalyzed under neutral conditions by a dearomatized ruthenium-pincer PNN complex and proceeds in toluene under an inert atmosphere with a high turnover number (up to 1000). PNP analogues do not catalyze this transformation, underlining the crucial importance of the amine arm of the pincer ligand. A mechanism is proposed involving metal-ligand cooperation via aromatization-dearomatization of the pyridine moiety and hemilability of the amine arm.
Preparation and Characterization of 1,5-Diacyl-2,4-dioxohexahydro-1,3,5-triazines with Higher Acyl Groups
Hofmann, Joerg,Just, Gerhard,Pritzkow, Wilhelm
, p. 67 - 71 (2007/10/02)
The title compounds were prepared from 2,4-dioxohexahydro-triazine (DHT) and the corresponding acid chlorides in the presence of sulphuric acid.They are active acylating agents against piperidine in dioxane as the solvent.Only the diacyl derivatives of DHT with acyl chain lengths up to C6 react with aqueous solutions of sodium perborate forming the corresponding peroxy acids.
