1125-70-8Relevant academic research and scientific papers
Copper(II) acetate-catalyzed one-pot conversion of aldehydes into primary amides through a Beckmann-type rearrangement
Martínez-Asencio, Ana,Yus, Miguel,Ramón, Diego J.
, p. 3948 - 3951 (2012)
Copper(II) acetate is a versatile catalyst for the direct transformation of any type of aldehydes into primary amides by stoichiometric reaction with hydroxylamine in water. The catalyst could be recovered 10 times without losing its activity, just by a simple organic layer extraction of the product. The catalyst and the protocol avoid the use of any type of expensive and difficult to handle organic ligand, as well as bases, showing excellent yields, under mild reaction conditions. The great purity of the crude product permits its purification by a simple recrystallization process. The whole protocol fulfils the principle of green chemistry and sustainability, minimizing the use of organic solvents and any type of wastes.
Hydration of Aliphatic Nitriles Catalyzed by an Osmium Polyhydride: Evidence for an Alternative Mechanism
Babón, Juan C.,Esteruelas, Miguel A.,López, Ana M.,O?ate, Enrique
, p. 7284 - 7296 (2021/05/29)
The hexahydride OsH6(PiPr3)2 competently catalyzes the hydration of aliphatic nitriles to amides. The main metal species under the catalytic conditions are the trihydride osmium(IV) amidate derivatives OsH3{κ2-N,O-[HNC(O)R]}(PiPr3)2, which have been isolated and fully characterized for R = iPr and tBu. The rate of hydration is proportional to the concentrations of the catalyst precursor, nitrile, and water. When these experimental findings and density functional theory calculations are combined, the mechanism of catalysis has been established. Complexes OsH3{κ2-N,O-[HNC(O)R]}(PiPr3)2 dissociate the carbonyl group of the chelate to afford κ1-N-amidate derivatives, which coordinate the nitrile. The subsequent attack of an external water molecule to both the C(sp) atom of the nitrile and the N atom of the amidate affords the amide and regenerates the κ1-N-amidate catalysts. The attack is concerted and takes place through a cyclic six-membered transition state, which involves Cnitrile···O-H···Namidate interactions. Before the attack, the free carbonyl group of the κ1-N-amidate ligand fixes the water molecule in the vicinity of the C(sp) atom of the nitrile.
A CO2-mediated base catalysis approach for the hydration of triple bonds in ionic liquids
Han, Buxing,Ke, Zhengang,Li, Ruipeng,Liu, Zhimin,Tang, Minhao,Wang, Yuepeng,Zeng, Wei,Zhang, Fengtao,Zhao, Yanfei
supporting information, p. 9870 - 9875 (2021/12/27)
Herein, we report a CO2-mediated base catalysis approach for the activation of triple bonds in ionic liquids (ILs) with anions that can chemically capture CO2 (e.g., azolate, phenolate, and acetate), which can achieve hydration of triple bonds to carbonyl chemicals. It is discovered that the anion-complexed CO2 could abstract one proton from proton resources (e.g., IL cation) and transfer it to the CN or CC bonds via a six-membered ring transition state, thus realizing their hydration. In particular, tetrabutylphosphonium 2-hydroxypyridine shows high efficiency for hydration of nitriles and CC bond-containing compounds under a CO2 atmosphere, affording a series of carbonyl compounds in excellent yields. This catalytic protocol is simple, green, and highly efficient and opens a new way to access carbonyl compounds via triple bond hydration under mild and metal-free conditions.
Base-controlled chemoselectivity: direct coupling of alcohols and acetonitriles to synthesise α-alkylated arylacetonitriles or acetamides
Bai, Liang,Ge, Min-Tong,Li, Chen,Qiu, Yuan-Rui,Wang, Ying,Xia, Ai-Bao,Xu, Dan-Qian
supporting information, p. 15200 - 15204 (2021/09/06)
We achieved chemoselective synthesis of α-alkylated arylacetonitriles and acetamides by combining Ir complex-catalysed direct coupling of alcohols and nitriles by a simple adjustment of the base. Methanol and ethanol performed well as the alkylating reagents. This method of acetonitrile alkylation provided a novel approach for carbon chain extension.
C(sp3)-H methylation enabled by peroxide photosensitization and Ni-mediated radical coupling
Vasilopoulos, Aristidis,Krska, Shane W.,Stahl, Shannon S.
, p. 398 - 403 (2021/05/06)
The “magic methyl” effect describes the change in potency, selectivity, and/or metabolic stability of a drug candidate associated with addition of a single methyl group. We report a synthetic method that enables direct methylation of C(sp3)-H bonds in diverse drug-like molecules and pharmaceutical building blocks. Visible light-initiated triplet energy transfer promotes homolysis of the O-O bond in di-tert-butyl or dicumyl peroxide under mild conditions. The resulting alkoxyl radicals undergo divergent reactivity, either hydrogen-atom transfer from a substrate C-H bond or generation of a methyl radical via b-methyl scission. The relative rates of these steps may be tuned by varying the reaction conditions or peroxide substituents to optimize the yield of methylated product arising from nickel-mediated cross-coupling of substrate and methyl radicals.
Preparation method of acyl primary amine
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Paragraph 0003; 0020-0023, (2021/12/08)
The invention discloses a preparation method of acyl primary amine. The preparation method of the acyl primary amine comprises the following step: in the presence of a catalyst, carrying out a heating reaction on terminal olefin, carbon monoxide and ammonium chloride to obtain the acyl primary amine, wherein the catalyst is at least one selected from Pd(tBu3P)2, Pd(Ph3P)2, Pd(dppp)2 and Pd(dFppb)2, the structural formula of the terminal olefin is R-CH=CH2, and R is any group. Under the action of the specific catalyst, the linear or branched acyl primary amine can be synthesized in a high regioselectivity manner, and the defect of an acylamine compound synthesis reaction in the aspect of regioselectivity in the prior art is overcome.
One-pot method for the synthesis of 1-aryl-2-aminoalkanol derivatives from the corresponding amides or nitriles
Bobal, Pavel,Otevrel, Jan,Svestka, David
, p. 25029 - 25045 (2020/07/14)
We have identified a novel one-pot method for the synthesis of β-amino alcohols, which is based on C-H bond hydroxylation at the benzylic α-carbon atom with a subsequent nitrile or amide functional group reduction. This cascade process uses molecular oxygen as an oxidant and sodium bis(2-methoxyethoxy)aluminum hydride as a reductant. The substrate scope was examined on 30 entries and, although the respective products were provided in moderate yields only, the above simple protocol may serve as a direct and powerful entry to the sterically congested 1,2-amino alcohols that are difficult to prepare by other routes. The plausible mechanistic rationale for the observed results is given and the reaction was applied to a synthesis of a potentially bioactive target. This journal is
Hydration of nitriles using a metal-ligand cooperative ruthenium pincer catalyst
Guo, Beibei,Otten, Edwin,De Vries, Johannes G.
, p. 10647 - 10652 (2019/12/02)
Nitrile hydration provides access to amides that are important structural elements in organic chemistry. Here we report catalytic nitrile hydration using ruthenium catalysts based on a pincer scaffold with a dearomatized pyridine backbone. These complexes catalyze the nucleophilic addition of H2O to a wide variety of aliphatic and (hetero)aromatic nitriles in tBuOH as solvent. Reactions occur under mild conditions (room temperature) in the absence of additives. A mechanism for nitrile hydration is proposed that is initiated by metal-ligand cooperative binding of the nitrile.
Ruthenium-Catalyzed Synthesis of N-Methylated Amides using Methanol
Paul, Bhaskar,Panja, Dibyajyoti,Kundu, Sabuj
supporting information, p. 5843 - 5847 (2019/08/26)
An efficient synthesis of N-methylated amides using methanol in the presence of a ruthenium(II) catalyst is realized. Notably, applying this process, tandem C-methylation and N-methylation were achieved to synthesize α-methyl N-methylated amides. In addition, several kinetic studies and control experiments with the plausible intermediates were performed to understand this novel protocol. Furthermore, detailed computational studies were carried out to understand the mechanism of this transformation.
Palladium-catalyzed regiodivergent hydroaminocarbonylation of alkenes to primary amides with ammonium chloride
Gao, Bao,Zhang, Guoying,Zhou, Xibing,Huang, Hanmin
, p. 380 - 386 (2018/01/12)
Palladium-catalyzed hydroaminocarbonylation of alkenes for the synthesis of primary amides has long been an elusive aim. Here, we report an efficient catalytic system which enables inexpensive NH4Cl to be utilized as a practical alternative to gaseous ammonia for the palladium-catalyzed alkene-hydroaminocarbonylation reaction. Through appropriate choice of the palladium precursors and ligands, either branched or linear primary amides can be obtained in good yields with good to excellent regioselectivities. Primary mechanistic studies were conducted and disclosed that electrophilic acylpalladium species were capable of capturing the NH2-moiety from ammonium salts to form amides in the presence of CO with NMP as a base.
