- Effect of ligand and bridge substitution on chiral recognition of 1-phenylethylammonium cation by an anionic binuclear Ni(II) complex
-
Chiral recognition is an important phenomenon. Identifying factors those influences recognition and resolution have significance in multiple areas. Earlier, we had reported recognition and resolution (30% ee) of 1-phenylethylammonium cation using an anion
- Das, Chandani Rani,Dutta, Tanmay,Ray, Manabendra
-
-
Read Online
- Simultaneous chirality sensing of multiple amines by 19F NMR
-
The rapid detection and differentiation of chiral compounds is important to synthetic, medicinal, and biological chemistry. Palladium complexes with chiral pincer ligands are demonstrated to have utility in determining the chirality of various amines. The binding of enantiomeric amines induces distinct 19F NMR shifts of the fluorine atoms appended on the ligand that defines a chiral environment around palladium. It is further demonstrated that this method has the ability to evaluate the enantiomeric composition and discriminate between enantiomers with chiral centers several carbons away from the binding site. The wide detection window provided by optimized chiral chemosensors allows the simultaneous identification of as many as 12 chiral amines. The extraordinary discriminating ability of this method is demonstrated by the resolution of chiral aliphatic amines that are difficult to separate using chiral chromatography.
- Zhao, Yanchuan,Swager, Timothy M.
-
-
Read Online
- A dual-catalysis anion-binding approach to the kinetic resolution of amines: Insights into the mechanism via a combined experimental and computational study
-
Racemic benzylic amines undergo kinetic resolution via benzoylation with benzoic anhydride in the presence of a dual catalyst system consisting of a readily available amide-thiourea catalyst and 4-dimethylaminopyridine (DMAP). An evaluation of various exp
- Mittal, Nisha,Lippert, Katharina M.,De, Chandra Kanta,Klauber, Eric G.,Emge, Thomas J.,Schreiner, Peter R.,Seidel, Daniel
-
-
Read Online
- Three-Component Iminolactonization Reaction via Bifunctionalization of Olefins Using Molecular Iodine and Visible Light
-
A novel three-component ?-iminolactonization reaction was developed, which relied on the C-C/C-O bond-forming bifunctionalization of olefins using molecular iodine and visible light. This strategy did not require any (heavy) metal reagents for double-bond activation because molecular iodine acted as a rare-metal-alternative reagent through visible light irradiation. In addition, the preactivation of amines and other substrates is not required. The mechanistic investigation revealed that the generated iodine radicals under visible light irradiation reacted with alkenes to form a highly reactive intermediate; then, the three-component reaction of diiodide, malonate, and amine furnished iminolactone. Of note, the developed reaction is simple and realized the diversity-oriented synthesis innovative methodology of ?-iminolactone derivatives in drug discovery chemistry.
- Itoh, Akichika,Maejima, Saki,Yamaguchi, Eiji
-
-
Read Online
- AMINE-BORANES AS BIFUNCTIONAL REAGENTS FOR DIRECT AMIDATION OF CARBOXYLIC ACIDS
-
The present invention generally relates to a process for selective and direct activation and subsequent amidation of aliphatic and aromatic carboxylic acids to afford an amide R3CONR1R2. That the process is capable of delivering gaseous or low-boiling point amines provides a major advantage over existing methodologies, which involves an intermediate of triacyloxyborane-amine complex [(R3CO2)3—B—NHR1R2]. This procedure readily produces primary, secondary, and tertiary amides, and is compatible with the chirality of the acid and amine involved. The preparation of known pharmaceutical molecules and intermediates has also been demonstrated.
- -
-
Paragraph 0008-0009; 0063-0064
(2022/03/04)
-
- Generation of Oxyphosphonium Ions by Photoredox/Cobaloxime Catalysis for Scalable Amide and Peptide Synthesis in Batch and Continuous-Flow
-
Phosphine-mediated deoxygenative nucleophilic substitutions, such as the Mitsunobu reaction, are of great importance in organic synthesis. However, the conventional protocols require stoichiometric oxidants to trigger the formation of the oxyphosphonium i
- Chen, Xiangyang,Houk, Kendall N.,Mo, Jia-Nan,Su, Junqi,Umanzor, Alexander,Zhang, Zheng,Zhao, Jiannan
-
supporting information
(2022/01/06)
-
- Design and synthesis of 3,3′-triazolyl biisoquinoline N,N’-dioxides via Hiyama cross-coupling of 4-trimethylsilyl-1,2,3-triazoles
-
A new strategy to effectively lock the conformation of substituents at the 3,3′-positions of axial-chiral biisoquinoline N,N’-dioxides was developed based on the strong dipole–dipole interaction between 1,2,3-triazole and pyridine N-oxide rings. The crystal structure and the DFT calculations of 3,3′-bis(1-benzyl-1H-1,2,3-triazole-4-yl)-1,1′-biisoquinoline N,N’-dioxide (3a) provided strong support for this strategy. Furthermore, we successfully demonstrated that readily available 4-trimethylsilyl-1,2,3-triazoles are viable nucleophiles for Hiyama cross-coupling.
- Sun, Shiyu,Reep, Carlyn,Zhang, Chenrui,Captain, Burjor,Peverati, Roberto,Takenaka, Norito
-
-
- Nickel-Catalyzed Asymmetric Synthesis of α-Arylbenzamides
-
A nickel-catalyzed asymmetric reductive hydroarylation of vinyl amides to produce enantioenriched α-arylbenzamides is reported. The use of a chiral bisimidazoline (BIm) ligand, in combination with diethoxymethylsilane and aryl halides, enables the regioselective introduction of aryl groups to the internal position of the olefin, forging a new stereogenic center α to the N atom. The use of neutral reagents and mild reaction conditions provides simple access to pharmacologically relevant motifs present in anticancer, SARS-CoV PLpro inhibitors, and KCNQ channel openers.
- Cuesta-Galisteo, Sergio,Sch?rgenhumer, Johannes,Wei, Xiaofeng,Merino, Estíbaliz,Nevado, Cristina
-
supporting information
p. 1605 - 1609
(2020/12/01)
-
- Facile Synthesis of Chiral Arylamines, Alkylamines and Amides by Enantioselective NiH-Catalyzed Hydroamination
-
Regio- and enantioselective hydroarylamination, hydroalkylamination and hydroamidation of styrenes have been developed by NiH catalysis with a simple bioxazoline ligand under mild conditions. A wide range of enantioenriched benzylic arylamines, alkylamines and amides can be easily accessed by nitroarenes, hydroxylamines and dioxazolones, respectively as amination reagents. The chiral induction in these reactions is proposed to proceed through an enantiodifferentiating syn-hydronickellation step.
- Meng, Lingpu,Yang, Jingjie,Duan, Mei,Wang, You,Zhu, Shaolin
-
supporting information
p. 23584 - 23589
(2021/09/28)
-
- Chiral separation materials based on derivatives of 6-amino-6-deoxyamylose
-
In order to develop new type of chiral separation materials, in this study, 6-amino-6-deoxyamylose was used as chiral starting material with which 10 derivatives were synthesized. The amino group in 6-amino-6-deoxyamylose was selectively acylated and then the hydroxyl groups were carbamoylated yielding amylose 6-amido-6-deoxy-2,3-bis(phenylcarbamate)s, which were employed as chiral selectors (CSs) for chiral stationary phases of high-performance liquid chromatography. The resulted 6-amido-6-deoxyamyloses and amylose 6-amido-6-deoxy-2,3-bis(phenylcarbamate)s were characterized by IR, 1H NMR, and elemental analysis. Enantioseparation evaluations indicated that most of the CSs demonstrated a moderate chiral recognition capability. The 6-nonphenyl (6-nonPh) CS of amylose 6-cyclohexylformamido-6-deoxy-2,3-bis(3,5-dimethylphenylcarbamate) showed the highest enantioselectivity towards the tested chiral analytes; the phenyl-heterogeneous (Ph-hetero) CS of amylose 6-(4-methylbenzamido)-6-deoxy-2,3-bis(3,5-dimethylphenylcarbamate) baseline separated the most chiral analytes; the phenyl-homogeneous (Ph-homo) CS of amylose 6-(3,5-dimethylbenzamido)-6-deoxy-2,3-bis(3,5-dimethylphenylcarbamate) also exhibited a good enantioseparation capability among the developed CSs. Regarding Ph-hetero CSs, the enantioselectivity depended on the combination of the substituent at 6-position and that at 2- and 3-positions; as for Ph-homo CSs, the enantioselectivity was related to the substituent at 2-, 3-, and 6-positions; with respect to 6-nonPh CSs, the retention factor of most analytes on the corresponding CSPs was lower than that on Ph-hetero and Ph-homo CSPs in the same mobile phases, indicating π–π interactions did occur during enantioseparation. Although the substituent at 6-position could not provide π–π interactions, the 6-nonPh CSs demonstrated an equivalent or even higher enantioselectivity compared with the Ph-homo and Ph-hetero CSs.
- Gao, Ya-Ya,Zhang, Yu-Hang,Zhang, Shan,Chen, Wei,Bai, Zheng-Wu
-
supporting information
p. 899 - 914
(2021/10/07)
-
- Carboxylic Acid Deoxyfluorination and One-Pot Amide Bond Formation Using Pentafluoropyridine (PFP)
-
This work describes the application of pentafluoropyridine (PFP), a cheap commercially available reagent, in the deoxyfluorination of carboxylic acids to acyl fluorides. The acyl fluorides can be formed from a range of acids under mild conditions. We also demonstrate that PFP can be utilized in a one-pot amide bond formation via in situ generation of acyl fluorides. This one-pot deoxyfluorination amide bond-forming reaction gives ready access to amides in yields of ≤94%.
- Brittain, William D. G.,Cobb, Steven L.
-
p. 5793 - 5798
(2021/08/01)
-
- Carboxyesterase polypeptides for amide coupling
-
The present invention provides engineered carboxyesterase enzymes having improved properties as compared to a naturally occurring wild-type carboxyesterase enzymes, as well as polynucleotides encoding the engineered carboxyesterase enzymes, host cells capable of expressing the engineered carboxyesterase enzymes, and methods of using the engineered carboxyesterase enzymes in amidation reactions.
- -
-
Page/Page column 63-64; 68-72; 79-81
(2021/05/28)
-
- Method for preparing amide from carboxylic acid under irradiation of blue light by taking iridium and cobalt complexes as catalysts
-
The invention relates to a method for preparing amide from carboxylic acid under the irradiation of blue light by taking iridium and cobalt complexes as catalysts, and belongs to the field of chemistry. The method comprises the following step of: by taking R substituted carboxylic acid and R1' and R2' substituted amines as raw materials, triphenylphosphine as a deoxidizing agent, [Ir(dF(CF3)ppy)2(dtbbpy)]PF6 as a photocatalyst and Co(dmgH)(dmgH2)Cl2 as a metal complex catalyst, reacting in dichloromethane in an inert atmosphere and under the irradiation of blue light to obtain an amide compound, wherein R is an aryl group, a heteroaryl group, a protected amino group, a substituted alkyl group, a substituted aryl group or a substituted protected amino group, R1' is a hydrogen group, a substituted alkyl group, a phenyl group or a substituted phenyl group, and R2' is a hydrogen group, a substituted alkyl group, a phenyl group or a substituted phenyl group.
- -
-
Paragraph 0093-0094
(2021/05/12)
-
- Zirconium Oxide-Catalyzed Direct Amidation of Unactivated Esters under Continuous-Flow Conditions
-
A sustainable and environmentally benign direct amidation reaction of unactivated esters with amines has been developed in a continuous-flow system. A commercially available amorphous zirconium oxide was found to be an efficient catalyst for this reaction. While the typical amidation of esters with amines requires a stoichiometric amount of a promoter or metal activator, the present continuous-flow method enabled the direct amidation reaction under additive-free conditions with an extensive diversity towards various functional groups. High yields of the products were obtained with a nearly equimolar proportion of starting materials to reduce byproduct formation, which renders this process applicable for use in a sequential-flow system. (Figure presented.).
- Rashed, Md. Nurnobi,Masuda, Koichiro,Ichitsuka, Tomohiro,Koumura, Nagatoshi,Sato, Kazuhiko,Kobayashi, Shū
-
p. 2529 - 2535
(2021/02/01)
-
- Regio- And Stereoselective (S N2) N -, O -, C - And S -Alkylation Using Trialkyl Phosphates
-
Bimolecular nucleophilic substitution (S N 2) is one of the most well-known fundamental reactions in organic chemistry to generate new molecules from two molecules. In principle, a nucleophile attacks from the back side of an alkylating agent having a suitable leaving group, most commonly a halide. However, alkyl halides are expensive, very harmful, toxic and not so stable, which makes them problematic for laboratory use. In contrast, trialkyl phosphates are inexpensive, readily accessible and stable at room temperature, under air, and are easy to handle, but rarely used as alkylating agents in organic synthesis. Here, we describe a mild, straightforward and powerful method for nucleophilic alkylation of various N -, O -, C - and S -nucleophiles using readily available trialkyl phosphates. The reaction proceeds smoothly in excellent yield, and quantitative yield in many cases, and covers a wide range of substrates. Further, the rare stereoselective transfer of secondary alkyl groups has been achieved with inversion of configuration of chiral centers (up to 98% ee).
- Banerjee, Amit,Hattori, Tomohiro,Yamamoto, Hisashi
-
-
- Fluorinated solvent-assisted photocatalytic aerobic oxidative amidation of alcoholsviavisible-light-mediated HKUST-1/Cs-POMoW catalysis
-
Considering the irreplaceable importance of photocatalytic functionalization reactions and the widespread attention paid to the use of metal-organic frameworks, especially their modified variants, for this purpose in recent years, different types of HKUST-1/POMoW composites were prepared through the immobilization of a series of Keggin-type polyoxometalates (POMs; POW = H3PW12O40, POMo = H3PMo12O40, and POMoW = H3PMo6W6O40) on HKUST-1 as a metal-organic framework (HKUST-1; Cu3(1,3,5-benzenetricarboxilicacid)2). Then, to produce HKUST-1/Cs-POM, the substitution of H+cations with Cs+ones as counter cations was carried out. The prepared composites were fully characterized with the PXRD (powder X-ray diffraction), FT-IR (Fourier transform infrared spectroscopy), BET and BJH (sorption of N2), TGA (thermo-gravimetric analysis), SEM (scanning electron microscopy), EDX (energy dispersive X-ray), TEM (transmission electron microscopy), UV-vis DRS (diffuse reflectance UV-vis spectroscopy), photoluminescence (PL) spectroscopy and ICP-AES (inductively coupled plasma atomic emission spectroscopy) techniques. The great importance?of the amide functional group and the attractiveness of photocatalytic oxidative functionalization?reactions led us to study the formation of this functional group using the prepared catalytic system in line with our previous research in this field. The HKUST-1/Cs-POMoW composite showed a raised photocatalytic performance compared to the discrete components, HKUST-1 and Cs-POMs, in aerobic oxidative amidation of alcohols under illumination with visible light, owing to the presence of catalytically active Cs-POMs deposited on the MOF particles. Besides, the combination of composite components mitigated the recombination rate of the electron-hole pairs, raising its photocatalytic activity. The attractiveness of fluorine solvents for oxidation reactions has led to the study of their role in the efficiency of oxidative amidation of alcohols and their significant effect on the efficiency of the process has been confirmed. The Cu-MOF/POM catalyst showed excellent stability during the reaction, and no significant decrease in its ability was observed during five consecutive cycles.
- Azarkhosh, Zahra,Heydari, Akbar,Karimi, Meghdad,Mahjoub, Alireza,Mohebali, Haleh,Sadeghi, Samira,Safarifard, Vahid
-
supporting information
p. 14024 - 14035
(2021/08/16)
-
- Direct enantioseparation of axially chiral 1,1′-biaryl-2,2′-diols using amidine-based resolving agents
-
Amidine-based optically active resolving agents for enantiomer separation of axially chiral 1,1′-biaryl-2,2′-diols have been developed. A strongly basic amidine bearing no substituents on its nitrogen atoms enables the formation of their diastereomeric salts upon being mixed with weakly acidic phenol derivatives. Enantiopure 1,1′-biaryl-2,2′-diols can be obtained in high yields after only one crystallization of their salts with the chiral amidine derived from dehydroabietic acid. X-ray crystallography revealed that the amidine moiety forms a salt with the phenol group and additional intermolecular NH/π interactions contribute to the efficient chiral recognition process.
- Hirose, Takuji,Kodama, Koichi,Takase, Fusato
-
p. 18162 - 18170
(2021/06/07)
-
- Novel chiral stationary phases based on 3,5-dimethyl phenylcarbamoylated β-cyclodextrin combining cinchona alkaloid moiety
-
Novel chiral selectors based on 3,5-dimethyl phenylcarbamoylated β-cyclodextrin connecting quinine (QN) or quinidine (QD) moiety were synthesized and immobilized on silica gel. Their chromatographic performances were investigated by comparing to the 3,5-dimethyl phenylcarbamoylated β-cyclodextrin (β-CD) chiral stationary phase (CSP) and 9-O-(tert-butylcarbamoyl)-QN-based CSP (QN-AX). Fmoc-protected amino acids, chiral drug cloprostenol (which has been successfully employed in veterinary medicine), and neutral chiral analytes were evaluated on CSPs, and the results showed that the novel CSPs characterized as both enantioseparation capabilities of CD-based CSP and QN/QD-based CSPs have broader application range than β-CD-based CSP or QN/QD-based CSPs. It was found that QN/QD moieties play a dominant role in the overall enantioseparation process of Fmoc-amino acids accompanied by the synergistic effect of β-CD moiety, which lead to the different enantioseparation of β-CD-QN-based CSP and β-CD-QD-based CSP. Furthermore, new CSPs retain extraordinary enantioseparation of cyclodextrin-based CSP for some neutral analytes on normal phase and even exhibit better enantioseparation than the corresponding β-CD-based CSP for certain samples.
- Zhu, Lunan,Zhu, Junchen,Sun, Xiaotong,Wu, Yaling,Wang, Huiying,Cheng, Lingping,Shen, Jiawei,Ke, Yanxiong
-
p. 1080 - 1090
(2020/05/25)
-
- Ruthenium Catalyzed Direct Asymmetric Reductive Amination of Simple Aliphatic Ketones Using Ammonium Iodide and Hydrogen
-
The direct conversion of ketones into chiral primary amines is a key transformation in chemistry. Here, we present a ruthenium catalyzed asymmetric reductive amination (ARA) of purely aliphatic ketones with good yields and moderate enantioselectivity: up to 99 percent yield and 74 percent ee. The strategy involves [Ru(PPh3)3H(CO)Cl] in combination with the ligand (S,S)-f-binaphane as the catalyst, NH4I as the amine source and H2 as the reductant. This is a straightforward and user-friendly process to access industrially relevant chiral aliphatic primary amines. Although the enantioselectivity with this approach is only moderate, to the extent of our knowledge, the maximum ee of 74 percent achieved with this system is the highest reported till now apart from enzyme catalysis for the direct transformation of ketones into chiral aliphatic primary amines.
- Ernst, Martin,Ghosh, Tamal,Hashmi, A. Stephen K.,Schaub, Thomas
-
supporting information
(2020/07/14)
-
- Amine-boranes as Dual-Purpose Reagents for Direct Amidation of Carboxylic Acids
-
Amine-boranes serve as dual-purpose reagents for direct amidation, activating aliphatic and aromatic carboxylic acids and, subsequently, delivering amines to provide the corresponding amides in up to 99% yields. Delivery of gaseous or low-boiling amines as their borane complexes provides a major advantage over existing methodologies. Utilizing amine-boranes containing borane incompatible functionalities allows for the preparation of functionalized amides. An intermolecular mechanism proceeding through a triacyloxyborane-amine complex is proposed.
- Choudhary, Shivani,Hamann, Henry J.,Ramachandran, P. Veeraraghavan
-
-
- Graphene oxide: A convenient metal-free carbocatalyst for facilitating amidation of esters with amines
-
Herein, we report a graphene oxide (GO) catalyzed condensation of non-activated esters and amines, that can enable diverse amides to be synthesized from abundant ethyl esters forming only volatile alcohol as a by-product. GO accelerates ester to amide conversion in the absence of any additives, unlike other catalysts. A wide range of ester and amine substrates are screened to yield the respective amides in good to excellent yields. The improved catalytic activity can be ascribed to the oxygenated functionalities present on the graphene oxide surface which forms H-bonding with the reactants accelerating the reaction. Improved yields and a wide range of functional group tolerance are some of the important features of the developed protocol.
- Patel, Khushbu P.,Gayakwad, Eknath M.,Shankarling, Ganapati S.
-
p. 2661 - 2668
(2020/02/20)
-
- PROCESS FOR PRODUCING ORGANIC COMPOUND
-
The present disclosure provides a reaction of a chlorine-containing compound using a flow reactor which is less restricted by a solvent to be used. In the present disclosure, an organic compound is produced by supplying a reaction substrate having at least one functional group which can react with chlorine and is selected from the group consisting of hydroxy group, a thiol group, an amino group, a carboxyl group, a thiocarboxyl group, and an acid amide group, and a chlorine-containing compound to a flow reactor together with a trialkyl amine having 9 to 40 carbon atoms and an organic solvent, and allowing the reaction substrate and the chlorine-containing compound to react with each other.
- -
-
Paragraph 0158
(2019/05/24)
-
- A Diaminopropane Diolefin Ru(0) Complex Catalyzes Hydrogenation and Dehydrogenation Reactions
-
New ruthenium (0) complexes with a cooperative diolefin diaminopropane (DAP) or the dehydrogenated iminopropenamide ligand (IPA) were synthesized for comparison with their diaminoethane (DAE)/ diazadiene (DAD) ruthenium analogues. These DAP/IPA complexes are efficient catalysts in dehydrogenation reactions of alkaline aqueous methanol which proceeds under mild conditions (T=70 °C) and of higher alcohols, forming the corresponding carbonate and carboxylates, respectively. The scope of the reaction includes an example of a 1,2-diol as model for biomass derived alcohols. Their catalytic applications are extended to the atom-efficient dehydrogenative coupling of alcohols and amines to amides. The reaction proceeds without any additives and is applicable to the synthesis of formamides from methanol. Moreover, DAP/IPA complexes catalyze the hydrogenation of a series of esters, lactone, ketone, activated olefin, aldehyde and imine substrates. The diaminopropane Ru catalyst exhibits higher activity compared to the dehydrogenated β-ketiminate (IPA) and previously studied DAD/DAE based catalysts. We present studies on their stoichiometric reactivity with relevance to their possible catalytic mechanisms and the isolation and full characterization of key reaction intermediates.
- Casas, Fernando,Trincado, Monica,Rodriguez-Lugo, Rafael,Baneerje, Dipshikha,Grützmacher, Hansj?rg
-
p. 5241 - 5251
(2019/11/16)
-
- Graphene Oxide: A Metal-Free Carbocatalyst for the Synthesis of Diverse Amides under Solvent-Free Conditions
-
An environmentally friendly, inexpensive, carbocatalyst, graphene oxide (GO) promoted efficient, metal-free transamidation of various carboxamides with aliphatic, cyclic, and aromatic amines is demonstrated. The protocol is equally applicable to phthalimide, urea, and thioamide determining its adaptability. The oxygenated functionalities such as carbonyl (?C=O), epoxy (?O?), carboxyl (?COOH) and hydroxyl (?OH), present on graphene oxide surface impart acidic properties to the catalyst. The graphene oxide being heterogeneous in nature, work efficiently under solvent-free reaction conditions providing desired products in good to excellent yields. The one-pot synthesis of 2,3-Dihydro-5H-benzo[b]-1,4-thiazepin-4-one moiety by GO catalyzed Aza Michael addition followed by intramolecular transamidation is also described. A plausible reaction mechanistic pathway involving H-bonding is discussed. The graphene oxide can be recycled and reused up to five cycles without much loss in catalytic activity. (Figure presented.).
- Patel, Khushbu P.,Gayakwad, Eknath M.,Patil, Vilas V.,Shankarling, Ganapati S.
-
supporting information
p. 2107 - 2116
(2019/03/26)
-
- Nickel-Catalyzed Amide Bond Formation from Methyl Esters
-
Despite being one of the most important and frequently run chemical reactions, the synthesis of amide bonds is accomplished primarily by wasteful methods that proceed by stoichiometric activation of one of the starting materials. We report a nickel-catalyzed procedure that can enable diverse amides to be synthesized from abundant methyl ester starting materials, producing only volatile alcohol as a stoichiometric waste product. In contrast to acid- and base-mediated amidations, the reaction is proposed to proceed by a neutral cross coupling-type mechanism, opening up new opportunities for direct, efficient, chemoselective synthesis.
- Ben Halima, Taoufik,Masson-Makdissi, Jeanne,Newman, Stephen G.
-
supporting information
p. 12925 - 12929
(2018/09/14)
-
- CuH-Catalyzed Asymmetric Hydroamidation of Vinylarenes
-
A CuH-catalyzed enantioselective hydroamidation reaction of vinylarenes has been developed using readily accessible 1,4,2-dioxazol-5-ones as electrophilic amidating reagents. This method provides a straightforward and efficient approach to synthesize chiral amides in good yields with high levels of enantiopurity under mild conditions. Moreover, this transformation tolerates substrates bearing a broad range of functional groups.
- Zhou, Yujing,Engl, Oliver D.,Bandar, Jeffrey S.,Chant, Emma D.,Buchwald, Stephen L.
-
p. 6672 - 6675
(2018/06/11)
-
- Resolution of racemic amines via lipase-catalyzed benzoylation: Chemoenzymatic synthesis of the pharmacologically active isomers of labetalol
-
Lipase-catalyzed benzoylation of amines was shown to be feasible, in some cases with high enantioselectivity, and the best results were obtained using immobilized lipase from Candida antarctica (Novozym 435) and methyl benzoate as acyl donor in the presence of molecular sieves. The procedure was optimized for the resolution of (±)-1-methyl-3-phenylpropylamine, a key intermediate in the synthesis of antihypertensive drug labetalol, and the enantiopure (R)-benzamide was then converted into the pharmacologically active isomers of the drug. In comparison with the reported synthesis of chiral isomers of labetalol, this chemoenzymatic route offers the advantage in the lack of any chiral stoichiometric auxiliary.
- Sanfilippo, Claudia,Paternò, Alfio Adriano,Patti, Angela
-
-
- A Practical Electrophilic Nitrogen Source for the Synthesis of Chiral Primary Amines by Copper-Catalyzed Hydroamination
-
A mild and practical method for the catalytic installation of the amino group across alkenes and alkynes has long been recognized as a significant challenge in synthetic chemistry. As the direct hydroamination of olefins using ammonia requires harsh conditions, the development of suitable electrophilic aminating reagents for formal hydroamination methods is of importance. Herein, we describe the use of 1,2-benzisoxazole as a practical electrophilic primary amine source. Using this heterocycle as a new amino group delivery agent, a mild and general protocol for the copper-hydride-catalyzed hydroamination of alkenes and alkynes to form primary amines was developed. This method provides access to a broad range of chiral α-branched primary amines and linear primary amines, as demonstrated by the efficient synthesis of the antiretroviral drug maraviroc and the formal synthesis of several other pharmaceutical agents.
- Guo, Sheng,Yang, Jeffrey C.,Buchwald, Stephen L.
-
p. 15976 - 15984
(2018/11/23)
-
- Imidazolium chloride: An efficient catalyst for transamidation of primary amines
-
A highly efficient and convenient protocol of imidazolium chloride (30 mol %) catalyzed amidation of amines with moderate to excellent yields was reported. The protocol shows broad substrate scope for aromatic, aliphatic, and heterocyclic primary amines.
- Tian, Qingqiang,Gan, Zongjie,Wang, Xuetong,Li, Dan,Luo, Wen,Wang, Huajun,Dai, Zeshu,Yuan, Jianyong
-
supporting information
(2018/09/10)
-
- Copper-amino group complexes supported on silica-coated magnetite nanoparticles: Efficient catalyst for oxidative amidation of methyl arenes
-
Magnetite nanoparticles coated with mesoporous silica, Fe3O4@SiO2, were prepared. Surface functionalization of this core-shell nanocomposite with (3-aminopropyl)trimethoxysilane (APTMS) followed by its reaction with Cu(OAc)2 was used to develop a new heterogeneous copper complex (Fe3O4@SiO2-APTMS-Cu). The structure and composition of the synthesized nanocatalyst were characterized by FTIR, SEM, VSM, TEM, XRD, and ICP analyses. The catalytic activity of the synthesized catalyst was probed in the oxidative amidation reaction of methyl arenes with amine hydrochloride salts. Various primary, secondary, and tertiary amides were prepared by this method. The magnetic properties of this catalyst lead to easy separation as well as providing significant catalyst recyclability. The catalyst is reusable 6 times without significant decrease in its catalytic activity.
- Karimi, Meghdad,Ghandi, Leila,Saberi, Dariush,Heydari, Akbar
-
supporting information
p. 3900 - 3908
(2018/03/06)
-
- Mapping the structural boundaries of quasiracemate fractional crystallization using 2-substituted diarylamides
-
Video-assisted hot stage polarized light microscopy of 55 quasienantiomeric pairs, constructed from 22 chiral diarylamides that systematically differ in topology, reveals the structural boundaries of molecular shape to supramolecular assembly.
- Tinsley, Ian C.,Spaniol, Jacqueline M.,Wheeler, Kraig A.
-
p. 4601 - 4604
(2017/04/28)
-
- Asymmetric catalysis of the carbonyl-amine condensation: Kinetic resolution of primary amines
-
A Br?nsted acid catalyzed kinetic resolution of primary amines is described that is based on the condensation between an amine and a carbonyl compound. 1,3-Diketones react with racemic α-branched amines to furnish the corresponding enantioenriched enaminone and recovered starting material. Good to excellent enantioselectivity was observed with both aromatic and aliphatic primary amines. This process represents the first small-molecule catalyzed kinetic resolution of aliphatic amines.
- Das, Sayantani,Majumdar, Nilanjana,De, Chandra Kanta,Kundu, Dipti Sankar,Dohring, Arno,Garczynski, Anika,List, Benjamin
-
supporting information
p. 1357 - 1359
(2017/02/10)
-
- Ruthenium-catalyzed oxidative decyanative cross-coupling of acetonitriles with amines in air: A general access to primary to tertiary amides under mild conditions
-
Catalyzed by Ru and in the presence of air and nucleophiles such as amines or ammonia, activation of the C-CN bond could be easily achieved under mild conditions to produce primary to tertiary amides in good to excellent yields. The use of accessible and functional-group-tolerant starting materials, a cheap, low-loading and recyclable catalyst, ligand-free conditions and excellent product yields are the advantages of the method. Moreover, compared with the Ritter reaction and hydration methods, this novel reaction has more comprehensive application scope.
- Wang, Yuguang,Wu, Zhongli,Li, Qin,Zhu, Bingchun,Yu, Lei
-
p. 3747 - 3757
(2017/09/07)
-
- Eluent tolerance and enantioseparation recovery of chiral packing materials based on chitosan bis(phenylcarbamate)-(n-octyl urea)s for high performance liquid chromatography
-
The goal of the present work was to study the influence of the swelling of chitosan derivatives on the enantioseparation and the separation performance recovery of chiral stationary phases (CSPs) based on these derivatives. Therefore, six chitosan bis(phenylcarbamate)-(n-octyl urea)s were synthesized, which were coated on macroporous 3-aminopropyl silica gel affording new CSPs. Most of the CSPs demonstrated strong enantioseparation capability for the tested chiral compounds. The swelling capacity of the chitosan bis(phenylcarbamate)-(n-octyl urea)s in ethyl acetate, acetone and tetrahydrofuran (THF) was evaluated. Among the chitosan derivatives, the chitosan bis(3,5-dichlorophenylcarbamate)-(n-octyl urea) polymer showed the highest swelling capacity in ethyl acetate and THF. The polymer-based CSPs could be utilized with pure ethyl acetate and a normal phase containing 70% THF, but was damaged by pure THF. On the other hand, the separation performance of the damaged CSP could be recovered after it was allowed to stand for a period of time. The observations are important for the development and application of polysaccharide derivative-based CSPs.
- Wang, Jing,Huang, Shao-Hua,Chen, Wei,Bai, Zheng-Wu
-
supporting information
(2016/12/02)
-
- Practical Synthesis of Amides via Copper/ABNO-Catalyzed Aerobic Oxidative Coupling of Alcohols and Amines
-
A modular Cu/ABNO catalyst system has been identified that enables efficient aerobic oxidative coupling of alcohols and amines to amides. All four permutations of benzylic/aliphatic alcohols and primary/secondary amines are viable in this reaction, enabling broad access to secondary and tertiary amides. The reactions exhibit excellent functional group compatibility and are complete within 30 min-3 h at rt. All components of the catalyst system are commercially available.
- Zultanski, Susan L.,Zhao, Jingyi,Stahl, Shannon S.
-
supporting information
p. 6416 - 6419
(2016/06/09)
-
- Green synthesis of primary, secondary, and tertiary amides through oxidative amidation of methyl groups with amine hydrochlorides over recyclable CoFe2O4 NPs
-
A practical and efficient method is developed for efficient synthesis of a wide variety of 1°, 2°, and 3° amides through amidation of methylarenes with amine hydrochloride salts, over magnetic CoFe2O4 NPs as a recyclable nanocatalyst, and aqueous tert-butyl hydroperoxide as an oxidant. This economically sound amidation reaction is operationally straightforward and provides desired amides in good to excellent yields, under mild conditions.
- Eidi, Esmaiel,Kassaee, Mohammad Zaman
-
p. 106873 - 106879
(2016/11/23)
-
- Metal-free oxidative nitration of α-carbon of carbonyls leads to one-pot synthesis of thiohydroximic acids from acetophenones
-
A metal-free nitration of the α-C-H to carbonyl in propiophenones was achieved with I2/NaNO2 in the presence of an oxidant in dimethyl sulfoxide (DMSO) as the medium. Conversely under similar conditions, reaction of acetophenones produced thiohydroximic acids via a radical-based cascade event which involves oxidative nitration of the α-carbon to a carbonyl followed by Michael addition of the thiomethyl group from DMSO and subsequent rearrangement. Besides DMSO, the scope of the reaction encompasses other symmetrical and unsymmetrical dialkylsulfoxides.
- Dighe, Shashikant U.,Mukhopadhyay, Sushobhan,Priyanka, Kumari,Batra, Sanjay
-
p. 4190 - 4193
(2016/09/09)
-
- Transamidation catalysed by a magnetically separable Fe3O4 nano catalyst under solvent-free conditions
-
An environmentally benign protocol for transamidation of carboxamides with different amines under solvent free conditions using magnetically separable nano Fe3O4 as a heterogeneous catalyst is developed. The series of aryl and alkyl amines with long chain alkyl substituents have been selectively converted into transamide products. The current protocol offers a diverse substrate scope with good yield of the product. The Fe3O4 nano catalyst has also been used for formylation of amines via transamidation of dimethyl formamide. Efficient transamidation, ease of work up, simple separation and reusability of the catalyst for up to six runs are the important highlights of this process.
- Thale, Pranila B.,Borase, Pravin N.,Shankarling, Ganapati S.
-
p. 52724 - 52728
(2016/06/14)
-
- A one-pot amidation of primary nitroalkanes
-
It has been over a half-century since Kornblum demonstrated the conversion of a primary nitroalkane to a carboxylic acid; addition of an amine results in carboxylic acid formation as well. We describe the formation of amides from terminal nitroalkanes in a two-step, one-pot reaction involving tandem halogenation/umpolung amide synthesis (UmAS).
- Schwieter, Kenneth E.,Johnston, Jeffrey N.
-
supporting information
p. 152 - 155
(2015/12/26)
-
- Copper-Catalyzed N-Benzoylation of Amines via Aerobic C-C Bond Cleavage
-
A general copper/air catalytic system for selectively oxidative C-C bond cleavage of 1,2-diarylethan-1-one has been developed, giving aromatic aldehydes and N-benzoylation products of various amines in moderate to excellent yields. This research provides an alternative approach for the N-benzoylation of amine in mild and neutral conditions.
- Fan, Wenyou,Yang, Youqing,Lei, Jianhua,Jiang, Qijian,Zhou, Wang
-
p. 8782 - 8789
(2015/09/15)
-
- Superparamagnetic Fe(OH)3@Fe3O4 nanoparticles: An efficient and recoverable catalyst for tandem oxidative amidation of alcohols with amine hydrochloride salts
-
Magnetic Fe(OH)3@Fe3O4 nanoparticles were successfully prepared and characterized. This magnetic nanocomposite was employed as an efficient, reusable, and environmentally benign heterogeneous catalyst for the direct amidation of alcohols with amine hydrochloride salts. Several derivatives of primary, secondary and tertiary amides were synthesized in moderate to good yields in the presence of this catalytic system. The catalyst was successfully recycled and reused up to six times without significant loss of its catalytic activity.
- Arefi, Marzban,Saberi, Dariush,Karimi, Meghdad,Heydari, Akbar
-
supporting information
p. 341 - 347
(2015/06/22)
-
- Catalyst and method for producing the same
-
PROBLEM TO BE SOLVED: To provide a method for producing an amide compound from a primary alcohol and at least one selected from a primary amine, a secondary amine and derivatives of those under relatively mild conditions with high selectivity and a high conversion ratio.SOLUTION: A method for producing an amide compound comprises a step of obtaining the amide compound from a primary alcohol and at least one selected from a primary amine, a secondary amine and derivatives of those, in the presence of a catalyst comprising a carrier formed by crosslinking a crosslinkable functional group of a styrene-based polymer having a side chain containing the crosslinkable functional group, and a nanosize cluster and carbon black supported on the carrier, wherein the nanosize cluster is at least one selected from a nanosize gold cluster and a nanosize cluster of gold and at least one group 8 metal selected from iron, cobalt and nickel.
- -
-
Paragraph 0073; 0075; 0093
(2016/11/07)
-
- Comprehensive Study of the Organic-Solvent-Free CDI-Mediated Acylation of Various Nucleophiles by Mechanochemistry
-
Acylation reactions are ubiquitous in the synthesis of natural products and biologically active compounds. Unfortunately, these reactions often require the use of large quantities of volatile and/or toxic solvents, either for the reaction, purification or isolation of the products. Herein we describe and discuss the possibility of completely eliminating the use of organic solvents for the synthesis, purification and isolation of products resulting from the acylation of amines and other nucleophiles. Thus, utilisation of N,N′-carbonyldiimidazole (CDI) allows efficient coupling between carboxylic acids and various nucleophiles under solvent-free mechanical agitation, and water-assisted grinding enables both the purification and isolation of pure products. Critical parameters such as the physical state and water solubility of the products, milling material, type of agitation (vibratory or planetary) as well as contamination from wear are analysed and discussed. In addition, original organic-solvent-free conditions are proposed to overcome the limitations of this approach. The calculations of various green metrics are included, highlighting the particularly low environmental impact of this strategy.
- Mtro, Thomas-Xavier,Bonnamour, Julien,Reidon, Thomas,Duprez, Anthony,Sarpoulet, Jordi,Martinez, Jean,Lamaty, Frdric
-
supporting information
p. 12787 - 12796
(2015/09/01)
-
- Zirconium-catalyzed direct amide bond formation between carboxylic esters and amines
-
Development of catalytic amide bond formation reactions from readily available starting materials remains a challenging task for modern organic chemistry. Herein, we report that unactivated carboxylic esters and amines react in the presence of 10 mol % of zirconocene dichloride (Cp2ZrCl2) in toluene at 110 °C to afford amides in very good to excellent conversions. The Zr-catalyzed reaction is amenable for the amidation of aliphatic and aromatic carboxylic esters with primary and secondary amines. The reaction proceeds with almost complete retention of configuration for chiral esters and chiral amines.
- Lenstra, Danny C.,Nguyen, D. Thao,Mecinovi?, Jasmin
-
p. 5547 - 5553
(2015/08/03)
-
- Microwave-Enhanced Asymmetric Transfer Hydrogenation of N-(tert-Butylsulfinyl)imines
-
Microwave irradiation has considerably enhanced the efficiency of the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)imines in isopropyl alcohol catalyzed by a ruthenium complex bearing the achiral ligand 2-amino-2-methylpropan-1-ol. In addition to shortening reaction times for the transfer hydrogenation processes to only 30 min, the amounts of ruthenium catalyst and isopropyl alcohol can be considerably reduced in comparison with our previous procedure assisted by conventional heating, which diminishes the environmental impact of this new protocol. This methodology can be applied to aromatic, heteroaromatic and aliphatic N-(tert-butylsulfinyl)ketimines, leading, after desulfinylation, to the expected primary amines in excellent yields and with enantiomeric excesses of up to 96 %. Microwave irradiation promotes the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)imines in 2-propanol catalysed by a ruthenium complex bearing an achiral β-amino alcohol as ligand. After desulfinylation, α-branched primary amines containing aromatic, heteroaromatic and aliphatic substituents are obtained in excellent yields and with enantiomeric excesses of up to 96 %.
- Pablo, Oscar,Guijarro, David,Yus, Miguel
-
p. 7034 - 7038
(2016/02/19)
-
- Kinetic resolution of primary amines via enantioselective N-acylation with acyl chlorides in the presence of supramolecular cyclodextrin nanocapsules
-
The non-enzymatic kinetic resolution of primary amines via enantioselective N-acylation with acyl chlorides was accomplished for the first time by using the selective sequestration of one enantiomer within a supramolecular cyclodextrin (CD) nanocapsule in nonpolar solvents. In addition, the first example of a crystalline structure for an inclusion complex between an acyl chloride and a CD derivative is reported.
- Asahara, Haruyasu,Kida, Toshiyuki,Iwamoto, Takuya,Hinoue, Tomoaki,Akashi, Mitsuru
-
p. 197 - 203
(2014/01/06)
-
- AIBN-initiated metal free amidation of aldehydes using N-chloroamines
-
An efficient and environmentally benign amidation of aldehydes with N-chloroamines has been developed using AIBN as an initiator. This methodology offers a metal free and base free approach and is endowed with mild reaction conditions, high yields, and good functional group tolerance.
- Vanjari, Rajeshwer,Guntreddi, Tirumaleswararao,Singh, Krishna Nand
-
p. 351 - 356
(2014/01/06)
-
- Transition-metal-free oxidative amidation of benzyl alcohols with amines catalyzed by NaI: A new method for the synthesis of benzamides Dedicated to the memory of Professor Ahmad Sodagar
-
A simple, inexpensive, and efficient method for the synthesis of benzamides via the reaction of benzyl alcohols and amine hydrochloride salts in the presence of NaI as a green catalyst is described. Various derivatives of benzamide were synthesized in moderate to good yields using this method.
- Karimi, Meghdad,Saberi, Dariush,Azizi, Kobra,Arefi, Marzban,Heydari, Akbar
-
p. 5351 - 5353
(2015/02/18)
-
- Direct oxidative amidation of benzyl alcohols using EDTA@Cu(II) functionalized superparamagnetic nanoparticles
-
Superparamagnetic Fe3O4@EDTA-Cu(II) nanoparticles were readily prepared and identified as an effective catalyst for the tandem transformation of benzyl alcohols and amine hydrochloride salts into the corresponding amides with tert-bu
- Azizi, Kobra,Karimi, Meghdad,Nikbakht, Fatemeh,Heydari, Akbar
-
p. 336 - 343
(2014/07/21)
-
- Oxidative amidation of aromatic aldehydes with amine hydrochloride salts catalyzed by silica-coated magnetic carbon nanotubes (MagCNTs@SiO 2)-immobilized imine-Cu(I)
-
Mesoporous silica-coated magnetic carbon nanotubes were prepared; their surface functionalization, followed by reaction with CuI, were carried out to develop a Cu-grafted functionalized mesoporous material. This system is able to catalyze oxidative amidation of aromatic aldehydes with amine hydrochloride salts, generating amide derivatives in moderate to good yields. Magnetic properties of this catalyst led to easy separation as well as providing significant recyclability.
- Saberi, Dariush,Heydari, Akbar
-
p. 101 - 108
(2014/02/14)
-