- FTIR investigation of solvent effects of N-methyl and N-tert-butyl benzamide
-
Infrared spectroscopy studies of N-methyl benzamide and N-tert-butyl benzamide in 12 organic solvents were undretaken to investigate solvent-solute interactions. The wavenumbers of carbonyl stretching vibration ν(C=O) in different solvents were correlated
- Jovi,Nikoli,Petrovi,Kordi,Crossed D Signakovi-Sekuli,Stojanovi
-
-
Read Online
- The Thermal Decomposition of N,O-Diacyl-N-t-butylhydroxylamines. IV. A Novel Acyloxyl Migration in N,O-Diacyl-N-t-butylhydroxylamines
-
Several N,O-diacyl-N-t-butylhydroxylamines were prepared, and their thermal decompositions were studied.N-Propionyl-O-benzoyl-N-t-butylhydroxylamine gave N-t-butyl-2-benzoyloxypropanamide, together with the decomposition products, N-t-butylpropanamide and benzoic acid, upon thermal decomposition in tetralin.Similar benzyloxyl migrations were found in the thermal decomposition of N-butyryl, N-valeryl, and N-(3-phenylpropionyl) derivatives.
- Uchida, Yuzuru,Kozuka, Seizi
-
-
Read Online
- Reactions of (E)-2-tert-Butyl-3-phenyloxaziridine with Lithium Amide
-
The reactions of (E)-2-tert-butyl-3-phenyloxaziridine (1a) with lithium amide bases in tetrahydrofuran have been studied.In competing rections, 1a is reduced to N-tert-butylbenzaldimine (2) and isomerized to N-tert-butylbenzamide (3).The former reaction proceeds through an intermediate which accumulates and slowly decomposes to 2; the reaction apparently occurs via an initial electron transfer from the base to the oxaziridine.The latter reaction occurs by simultaneous deprotonation and ring opening of the oxaziridine to give the anion of 3.
- Newcomb, Martin,Reeder, Robert A.
-
-
Read Online
- Borrowing and Returning Oxygen Atom in Trifluoroacetic Anhydride Transfer to Nitrones: A Versatile Route for the Synthesis of N-Trifluoroacetyl Amides
-
A method for the synthesis of N-trifluoroacetyl amides through trifluoroacetic anhydride transfer to nitrones by borrowing and returning oxygen atom is reported. The reaction appears to proceed via electrophilic trifluoroacetylation, followed by nucleophi
- Wang, Junwen,Weng, Zhiqiang
-
-
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)
-
- Remarkably Efficient Iridium Catalysts for Directed C(sp2)-H and C(sp3)-H Borylation of Diverse Classes of Substrates
-
Here we describe the discovery of a new class of C-H borylation catalysts and their use for regioselective C-H borylation of aromatic, heteroaromatic, and aliphatic systems. The new catalysts have Ir-C(thienyl) or Ir-C(furyl) anionic ligands instead of the diamine-type neutral chelating ligands used in the standard C-H borylation conditions. It is reported that the employment of these newly discovered catalysts show excellent reactivity and ortho-selectivity for diverse classes of aromatic substrates with high isolated yields. Moreover, the catalysts proved to be efficient for a wide number of aliphatic substrates for selective C(sp3)-H bond borylations. Heterocyclic molecules are selectively borylated using the inherently elevated reactivity of the C-H bonds. A number of late-stage C-H functionalization have been described using the same catalysts. Furthermore, we show that one of the catalysts could be used even in open air for the C(sp2)-H and C(sp3)-H borylations enabling the method more general. Preliminary mechanistic studies suggest that the active catalytic intermediate is the Ir(bis)boryl complex, and the attached ligand acts as bidentate ligand. Collectively, this study underlines the discovery of new class of C-H borylation catalysts that should find wide application in the context of C-H functionalization chemistry.
- Chattopadhyay, Buddhadeb,Hassan, Mirja Md Mahamudul,Hoque, Md Emdadul
-
supporting information
p. 5022 - 5037
(2021/05/04)
-
- Photochemical Activation of Aromatic Aldehydes: Synthesis of Amides, Hydroxamic Acids and Esters
-
A cheap, facile and metal-free photochemical protocol for the activation of aromatic aldehydes has been developed. Utilizing thioxanthen-9-one as the photocatalyst and cheap household lamps as the light source, a variety of aromatic aldehydes have been activated and subsequently converted in a one-pot reaction into amides, hydroxamic acids and esters in good to high yields. The applicability of this method was highlighted in the synthesis of Moclobemide, a drug against depression and social anxiety. Extended and detailed mechanistic studies have been conducted, in order to determine a plausible mechanism for the reaction.
- Nikitas, Nikolaos F.,Apostolopoulou, Mary K.,Skolia, Elpida,Tsoukaki, Anna,Kokotos, Christoforos G.
-
supporting information
p. 7915 - 7922
(2021/05/03)
-
- Insight into Regioselective Control in Aerobic Oxidative C-H/C-H Coupling for C3-Arylation of Benzothiophenes: Toward Structurally Nontraditional OLED Materials
-
The installation of (benzo)thiophene-containing biaryls via coupling reactions has become a staple in designing photoelectric materials. Undeniably, C-H/C-H cross-coupling reactions between two (hetero)aromatics would be a shortcut toward these structural fragments. While more reliable cross-coupling technologies are well-established to provide C2-arylated (benzo)thiophenes, efficient methods that arylate the C3-position remain underdeveloped. Herein we provide insight into the factors that determine regioselectivity switching for these cross-coupling reactions. X-ray crystallographic analysis gives solid evidence for the key roles of triflate in regioselective dearomatization and acetate in base-assisted anti-β-deprotonated rearomatization. The first isolation and X-ray characterization of a medium-sized dearomatized cyclometalated adduct involving both substrates provide extra insight into aerobic oxidative Ar-H/Ar-H cross-coupling reactions. The mechanistic breakthrough incubates the first example, enabling C-H/C-H-type C3-arylation of benzothiophenes. Finally, this chemistry is used to design blue-emitting thermally activated delayed fluorescence (TADF) materials with a helicene conformation that exhibit a high maximum external quantum efficiency of 25.4% in OLED.
- Bin, Zhengyang,Liao, Xingrong,Liu, Jiahui,Shen, Boming,Shi, Yang,Yan, Lipeng,Yang, Feng,Yang, Ge,Yang, Yudong,You, Jingsong,Yu, Peiyuan
-
supporting information
(2021/12/14)
-
- A case study of Pd?Pd intramolecular interaction in a benzothiazole based palladacycle; catalytic activity toward amide synthesisviaan isocyanide insertion pathway
-
An acetate bridge benzothiazolepalladacycle containing a rare metallophilic intramolecular Pd?Pd interaction was synthesized and thoroughly characterized. The synthesized benzothiazolepalladacycle directly anchored on SBA-15 to form an efficient heterogen
- Loni, Masood,Balmohammadi, Yaser,Dadgar Yeganeh, Reza,Imani, Kaveh,Notash, Behrouz,Bazgir, Ayoob
-
supporting information
p. 3290 - 3297
(2021/02/26)
-
- NaOTs-promoted transition metal-free C-N bond cleavage to form C-X (X = N, O, S) bonds
-
Multifunctional transformation of amide C-N bond cleavage is reported. The protocol applies to benzamide, thioamide, alcohols, and mercaptan under similar reaction conditions catalyzed by NaOTs. It is noteworthy that NaOTs can not only be recycled and reused for up to three cycles without significant loss in catalytic activity, but also catalyze gram-grade reactions. This study provides a novel solution with mild conditions and a simple procedure for transformation of multiple amides.
- Chen, Wei,Liu, Sicheng,Liu, Tingting,Majeed, Irfan,Ye, Xiaojing,Zeng, Zhuo,Zhang, Yuqi,Zhu, Yulin
-
p. 8566 - 8571
(2021/10/20)
-
- Weak base-promoted selective rearrangement of oxaziridines to amidesviavisible-light photoredox catalysis
-
The selective rearrangement of oxaziridines to amidesviaa single electron transfer (SET) pathway is unexplored. In this study, we present a weak base-promoted selective rearrangement of oxaziridines to amidesviavisible-light photoredox catalysis. The developed method shows excellent functional group tolerance with a broad substrate scope and good to excellent yields. Furthermore, control experiments and density functional theory (DFT) calculations are performed to gain insight into the reactivity and selectivity.
- Park, Jin,Park, Sehoon,Jang, Gwang Seok,Kim, Ran Hui,Jung, Jaehoon,Woo, Sang Kook
-
supporting information
p. 9995 - 9998
(2021/10/06)
-
- Catalyst-free synthesis of phenanthridinesviaelectrochemical coupling of 2-isocyanobiphenyls and amines
-
Catalyst free synthesis of 6-aryl phenanthridines and amides through an electrochemical reaction is reported in this study. The coupling reaction proceeds by the cathodic reduction ofin situformed diazonium ions, which are formed from anilines and an alkyl nitrite. The generated aryl radical diazonium ions coupled from isocyanides furnished the desired products in good yields. This cascade reaction was conducted in an undivided cell equipped with an RVC as the anode and Pt as the cathode usingnBu4NBF4as the electrolyte at room temperature. A series of detailed mechanistic studies have also been performed, including a radical clock experiment and cyclic voltammetry analysis.
- Malviya, Bhanwar Kumar,Singh, Karandeep,Jaiswal, Pradeep K.,Karnatak, Manvika,Verma, Ved Prakash,Badsara, Satpal Singh,Sharma, Siddharth
-
p. 6367 - 6378
(2021/04/16)
-
- 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 61-62; 65-66; 79-81
(2021/05/28)
-
- UV-Light-Induced N-Acylation of Amines with α-Diketones
-
Herein, we develop a mild method for N-acylation of primary and secondary amines with α-diketones induced by ultraviolet (UV) light. Forty-six examples with various functional groups are explored at room temperature with irradiation by three 26 W UV lamps (350-380 nm). The yield reaches 97%. The gram scale experiment product yield is 76%. Moreover, this system can be applied to the synthesis of several amino acid derivatives. Mechanistic studies show that benzoin is generated in situ from benzil under UV irradiation.
- Xu, Zhihui,Yang, Tianbao,Tang, Niu,Ou, Yifeng,Yin, Shuang-Feng,Kambe, Nobuaki,Qiu, Renhua
-
supporting information
p. 5329 - 5333
(2021/07/21)
-
- CoFe2O4?SiO2-NH-βCD-BF3 as a supramolecular nanocomposite: Synthesis, characterization and catalytic activity
-
This manuscript describes synthesis of BF3-functionlized β-cylcodextrine grafted magnetic CoFe2O4 nanaoparticles as a hybrid magnetic nano-composite (CoFe2O4?SiO2-NH-βCD-BF3). The CoFe2O4?SiO2-NH-βCD-BF3 was fabricated by grafting of 6-O-toluenesulfonyl cyclodextrin (6-Ts-βCD) to 3-aminopropyl triethoxysilane coated magnetic CoFe2O4?SiO2 nanoparticles followed by combination with BF3. The CoFe2O4?SiO2-NH-βCD-BF3was characterized by FT-IR, TGA, VSM and SEM techniques. The feasibility of using CoFe2O4?SiO2-NH-βCD-BF3 as a magnetically recoverable catalyst was confirmed in the modified-Ritter reaction. The result showed that this novel nano-composite could serve as an efficient nanoreactor bearing super-acidic sites formed by immobilized BF3 and reuse at least for 6 times without loss in activity.
- Hamadi, Hosein,Zanjani, Zohreh,Yadollahi, Mahtab
-
-
- Organophotoredox-Mediated Amide Synthesis by Coupling Alcohol and Amine through Aerobic Oxidation of Alcohol
-
The combination of an organic photocatalyst [4CzIPN (1,2,3,5-tetrakis(carbazol-9-yl)-4,6 dicyanobenzene) or 5MeOCzBN (2,3,4,5,6-pentakis(3,6-dimethoxy-9 H-carbazol-9-yl)benzonitrile)], quinuclidine, and tetra-n-butylammonium phosphate (hydrogen-bonding catalyst) was employed for amide bond formations. The hydrogen-bonded OH group activated the adjacent C?H bond of alcohols towards hydrogen atom transfer (HAT) by a radical species. The quinuclidinium radical cation, generated through single-electron oxidation of quinuclidine by the photocatalyst, employed to abstract a hydrogen atom from the α-C?H bond of alcohols selectively due to a polarity effect-produced α-hydroxyalkyl radical, which subsequently converted to the corresponding aldehyde under aerobic conditions. Then the coupling of the aldehyde and an amine formed a hemiaminal intermediate that upon photocatalytic oxidation produced the amide.
- Samanta, Samya,Shah, Sk. Sheriff,Shee, Maniklal,Singh, Amit Kumar,Singh, N. D. Pradeep,Venkatesh, Yarra
-
-
- Ionic liquid catalyzed Ritter reaction/Pd-catalyzed directed Ortho-arylation; facile access to diverse libraries of biaryl-amides from Aryl-nitriles
-
Diverse libraries of biaryl-amides bearing N-t-butyl and N-adamantyl groups were synthesized in two steps by the Ritter reaction of aryl-nitriles, using tBuOH and AdaOH as carbocation precursors, and employing [BMIM(SO3H)][OTf] (neat or with [B
- Sutar, Suraj M.,Savanur, Hemantkumar M.,Kalkhambkar, Rajesh G.,Borosky, Gabriela L.,Aridoss, Gopalakrishnan,Laali, Kenneth K.
-
supporting information
(2020/10/30)
-
- Chemoselective formation of C–N bond in wet acetonitrile using amberlyst-15(H) as a recyclable catalyst
-
An economically efficient and environmentally benign protocol for the chemoselective one-pot synthesis of diversely N-substituted amides has been developed in good yield through the reaction of benzylic secondary alcohols as well as aliphatic tertiary alcohols and alkyl/aryl nitriles. Commercially available Amberlyst-15(H) has been utilized at 80 °C as an air-stable and reusable heterogeneous inexpensive solid acid catalyst without any anhydrous and inert environment. The attractive features of the present synthetic protocol are mild reaction conditions, short reaction time, excellent chemoselectivity, high atom economy and tolerance of various sensitive moieties.
- Nandy, Sneha,Das, Asit Kumar,Bhar, Sanjay
-
supporting information
p. 3326 - 3336
(2020/08/13)
-
- Palladium-Catalyzed Para-Selective Difluoromethylation of Arene Esters
-
Highly efficient, palladium-catalyzed, para-selective difluoromethylation of arene esters has been developed using [1,1′-biphenyl]-2-dicyclohexylphosphine as the effective ligand. A wide variety of arene esters bearing various functional groups were all compatible with the reaction conditions, leading to para-difluoromethylated products in moderate to good yields. Moreover, benzoylamide and benzenesulfonamide were also well-tolerated, suggesting that this novel catalyst system has broad applications to a variety of substrates.
- Tu, Guangliang,Wang, Dongjie,Yuan, Chunchen,Zhang, Jingyu,Zhao, Yingsheng
-
p. 10740 - 10749
(2020/09/18)
-
- Tandem Photoredox Catalysis: Enabling Carbonylative Amidation of Aryl and Alkylhalides
-
We report a new visible-light-mediated carbonylative amidation of aryl, heteroaryl, and alkyl halides. A tandem catalytic cycle of [Ir(ppy)2(dtb-bpy)]+ generates a potent iridium photoreductant through a second catalytic cycle in the presence of DIPEA, which productively engages aryl bromides, iodides, and even chlorides as well as primary, secondary, and tertiary alkyl iodides. The versatile in situ generated catalyst is compatible with aliphatic and aromatic amines, shows high functional-group tolerance, and enables the late-stage amidation of complex natural products.
- Connell, Timothy U.,Forni, José A.,Micic, Nenad,Polyzos, Anastasios,Weragoda, Geethika
-
supporting information
p. 18646 - 18654
(2020/08/21)
-
- Copper-Catalyzed Radical N-Demethylation of Amides Using N-Fluorobenzenesulfonimide as an Oxidant
-
An unprecedented N-demethylation of N-methyl amides has been developed by use of N-fluorobenzenesulfonimide as an oxidant with the aid of a copper catalyst. The conversion of amides to carbinolamines involves successive single-electron transfer, hydrogen-atom transfer, and hydrolysis, and is accompanied by formation of N-(phenylsulfonyl)benzenesulfonamide. Carbinolamines spontaneously decompose to N-demethylated amides and formaldehyde, because of their inherent instability.
- Yi, Xuewen,Yi, Xuewen,Lei, Siyu,Liu, Wangsheng,Che, Fengrui,Yu, Chunzheng,Liu, Xuesong,Wang, Zonghua,Zhou, Xin,Zhang, Yuexia
-
supporting information
p. 4583 - 4587
(2020/05/05)
-
- Nickel-catalyzed aminocarbonylation of Aryl/Alkenyl/Allyl (pseudo)halides with isocyanides and H2O
-
Herein described is a nickel-catalyzed aminocarbonylation of aryl/alkenyl/allyl (pseudo)halides with isocyanides, providing aryl/alkenyl/allyl amides in 41% to 92% yields. Functional groups such as F, Cl, OMe, and heteroaromatic rings are compatible in the reaction. A Ni(0)/Ni(II) catalytic cycle is proposed based on preliminary experiments and previous literature. The reaction features readily available nickel salt, broad functional group tolerance, and simple reaction conditions.
- Li, Qiao,Cai, Yun,Jin, Hongwei,Liu, Yunkui,Zhou, Bingwei
-
supporting information
(2020/11/27)
-
- N-Acyl-glutarimides: Effect of Glutarimide Ring on the Structures of Fully Perpendicular Twisted Amides and N-C Bond Cross-Coupling
-
N-Acyl-glutarimides have emerged as the most reactive precursors for N-C(O) bond cross-coupling reactions to date, wherein the reactivity is driven by ground-state destabilization of the amide bond. Herein, we report a full study on the effect of a glutarimide ring on the structures, electronic properties, and reactivity of fully perpendicular N-acyl-glutarimide amides. Most notably, this report demonstrates the generality of deploying N-acyl-glutarimides to achieve full twist of the acyclic amide bond, and results in the discovery of N-acyl-glutarimide amide with an almost perfect twist value, τ = 89.1°. X-ray structures of five new N-acyl-glutarimides are reported. Reactivity studies in the Suzuki-Miyaura cross-coupling and transamidation reactions provide insight into the reactivity of N-acyl-glutarimides in metal-catalyzed and transition-metal-free reactions. The effect of distortion, structures, and rotational barriers around the N-C(O) axis is discussed. The ability to achieve full distortion of the amide bond significantly expands the range of reagents available for N-C(O) cross-coupling reactions.
- Bisz, Elwira,Chen, Hao,Dziuk, B?a?ej,Lalancette, Roger,Liu, Chengwei,Rahman, Md. Mahbubur,Szostak, Michal,Szostak, Roman,Wang, Qi
-
p. 5475 - 5485
(2020/05/19)
-
- 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
-
supporting information
(2020/11/13)
-
- A convenient synthesis of N-tert-butyl amides by the reaction of di-tert-butyl dicarbonate and nitriles catalyzed by Cu(OTf)2
-
The utility of Cu(OTf)2 as the catalyst for the synthesis of a series of N-tert-butyl amides in excellent isolated yields via the reaction of nitriles (alkyl, aryl, benzyl, and furyl nitriles) with di-tert-butyl dicarbonate is described. Cu(OTf)2 is a highly stable and efficient catalyst for the present Ritter reaction under solvent-free conditions at room temperature.
- Chen, Junqing,Feng, Chengliang,Ji, Min,Tang, Yuqi,Yang, Wanfeng
-
p. 602 - 608
(2020/04/27)
-
- 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)
-
- Two-step continuous flow synthesis of amide via oxidative amidation of methylarene
-
A green and efficient method for the synthesis of amides has been developed through oxidative amidation between methylarenes with amines in a two-step continuous flow system. This method integrates methylarene oxidation and amide formation into a single operation which is usually accomplished separately. Oxidation with tert-butyl hydroperoxide (TBHP) as “green” oxidant, the synthesis of amides under mild reaction conditions in continuous flow system and the utilization of methylarenes as starting material make this methodology novel and environment friendly. The practical value of this method is highlighted through the synthesis of high-profile pharmaceutical agents, acetylprocainamide.
- Fang, Zheng,Guo, Kai,He, Wei,Liu, Chengkou,Shi, Tingting,Yang, Yuhang,Yang, Zhao,Zhang, Zhimin
-
supporting information
(2020/02/28)
-
- Visible-Light Photoredox-Catalyzed Amidation of Benzylic Alcohols
-
A new photocatalyzed route to amides from alcohols and amines mediated by visible light is presented. The reaction is carried out in ethyl acetate as a solvent. Ethyl acetate can be defined a green and bio-based solvent. The starting materials such as the energy source are easily available, stable, and inexpensive. The reaction has shown to be general and high yielding.
- Gaspa, Silvia,Farina, Andrea,Tilocca, Mariella,Porcheddu, Andrea,Pisano, Luisa,Carraro, Massimo,Azzena, Ugo,De Luca, Lidia
-
p. 11679 - 11687
(2020/10/23)
-
- Oxidative amidation by Cu(ii)-guanidine acetic acid immobilized on magnetized sawdust with eggshell as a natural base
-
Copper(ii)-guanidine acetic acid complex was immobilized on the surface of magnetized raw waste sawdust (SD) as an abundant natural biopolymer and employed as an efficient and recoverable catalyst in oxidative amidation reaction, while waste eggshell (ES) powder was used as a low-cost solid base. The magnetic raw catalyst was fully characterized using FTIR, XRD, SEM, EDX, TGA, and VSM. A variety of amide derivatives were successfully synthesized in moderate to good yields using benzyl alcohol and amine salts. The application of sawdust and eggshell as two natural and abundant waste materials is the main advantage of this research. Moreover, these low-cost catalysts were recovered at least five times and utilized in reaction systems with a minimal decrease in activity.
- Arefi, Marzban,Darvishi, Atefeh,Heydari, Akbar,Kazemi Miraki, Maryam
-
p. 11777 - 11785
(2020/07/21)
-
- An efficient synthesis of N-tert-butyl amides by the reaction of tert-butyl benzoate with nitriles catalyzed by Zn(ClO4)2·6H2O
-
An efficient, mild and inexpensive synthesis of N-tert-butyl amides from the reaction of nitriles (aryl, benzyl and sec-alkyl nitriles) with tert-butyl benzoate catalyzed by the employment of 2?mol% Zn(ClO4)2·6H2O at 50?°C
- Feng, Cheng-Liang,Yan, Bin,Zhang, Min,Chen, Jun-Qing,Ji, Min
-
p. 535 - 542
(2019/02/12)
-
- An efficient transformation of methyl ethers and nitriles to amides catalyzed by Iron(III) perchlorate hydrate
-
An efficient and inexpensive synthesis of N-substituted amides from the reaction of nitriles with methyl ethers catalyzed by Fe(ClO4)3·H2O is described. Fe(ClO4)3·H2O is an economically efficient catalyst for the Ritter Reaction under solvent-free conditions. A range of methyl ethers (benzyl, sec-alkyl and tert-butyl ethers) were reacted with nitriles to provide the corresponding amides in high–excellent yields.
- Yin, Guibo,Yan, Bin,Chen, Junqing,Ji, Min
-
p. 1355 - 1363
(2019/04/30)
-
- Chemoselective Synthesis of α-Amino-α-cyanophosphonates by Reductive Gem-Cyanation-Phosphonylation of Secondary Amides
-
A novel approach to α-amino-α-cyanophosphonates has been developed. The method features a Tf2O-mediated reductive geminal cyanation/phosphonylation of secondary amides. Mild reaction conditions, high bond-forming efficiency, inexpensive readily available starting materials, and good to excellent yields with wide functional group compatibility constitute the main advantages of this method. The protocol can be run on a gram scale.
- Chen, Ting-Ting,Wang, Ai-E,Huang, Pei-Qiang
-
supporting information
p. 3808 - 3812
(2019/05/24)
-
- Tf2O-Mediated Intermolecular Coupling of Secondary Amides with Enamines or Ketones: A Versatile and Direct Access to β-Enaminones
-
Based on the Tf2O-mediated intermolecular reaction of secondary amides with enamines derived from ketones, a novel approach to β-enaminones has been developed. The reaction is widely functional group tolerant and highly chemoselective. In the presence of 4 ? molecular sieves, the method can be extended to the one-pot condensation of secondary amides with ketones for NH β-enaminones synthesis.
- Liu, Yong-Peng,Zhu, Cheng-Jie,Yu, Cun-Cun,Wang, Ai-E,Huang, Pei-Qiang
-
supporting information
p. 7169 - 7174
(2019/11/16)
-
- Selective C?N Bond Cleavage of N-Acylisatins: Towards High Performance Acylation/Arylation/Transamination Reagents
-
New multipurpose arylation/acylation/transamination reagents, N-acylisatins, have been developed by selective ‘inside-outside’ C?N bond cleavage under different catalytic conditions. As activated amides, N-acylisatins undergo Rh-catalyzed C?H arylation and Pd-catalyzed acylation by cleavage outside the C?N bond, and the desired biaryls and diaryl ketones were obtained in good to excellent yields. Generally, the combination of N-acylisatins with amines leads to a ring-opening reaction and formation of transamination products in a predictable manner through inside C?N bond cleavage. Interestingly, treatment of N-acylisatins with amines lead to unexpected outer-ring transamination products when CsF is added, which shows that CsF can favor the outside C?N bond cleavage path. Notably, this work presents a new strategy for multiple chemical transformations of a single amide to achieve various products by selective C?N bond cleavage. (Figure presented.).
- Xiong, Li,Deng, Rong,Liu, Tingting,Luo, Zhongfeng,Wang, Zijia,Zhu, Xiao-Feng,Wang, Hui,Zeng, Zhuo
-
p. 5383 - 5391
(2019/11/03)
-
- Clickable coupling of carboxylic acids and amines at room temperature mediated by SO2F2: A significant breakthrough for the construction of amides and peptide linkages
-
The construction of amide bonds and peptide linkages is one of the most fundamental transformations in all life processes and organic synthesis. The synthesis of structurally ubiquitous amide motifs is essential in the assembly of numerous important molecules such as peptides, proteins, alkaloids, pharmaceutical agents, polymers, ligands and agrochemicals. A method of SO2F2-mediated direct clickable coupling of carboxylic acids with amines was developed for the synthesis of a broad scope of amides in a simple, mild, highly efficient, robust and practical manner (>110 examples, >90% yields in most cases). The direct click reactions of acids and amines on a gram scale are also demonstrated using an extremely easy work-up and purification process of washing with 1 M aqueous HCl to provide the desired amides in greater than 99% purity and excellent yields.
- Wang, Shi-Meng,Zhao, Chuang,Zhang, Xu,Qin, Hua-Li
-
p. 4087 - 4101
(2019/04/30)
-
- Identifying Amidyl Radicals for Intermolecular C-H Functionalizations
-
Recent studies have demonstrated the capabilities of amidyl radicals to facilitate a range of intermolecular functionalizations of unactivated, aliphatic C-H bonds. Relatively little information is known regarding the important structural and electronic features of amidyl and related radicals that impart efficient reactivity. Herein, we evaluate a diverse range of nitrogen-centered radicals in unactivated, aliphatic C-H chlorinations. These studies establish the salient features of nitrogen-centered radicals critical to these reactions in order to expedite the future development of new site-selective, intermolecular C-H functionalizations.
- Tierney, Matthew M.,Crespi, Stefano,Ravelli, Davide,Alexanian, Erik J.
-
p. 12983 - 12991
(2019/10/02)
-
- Iodine-mediated aryl transfer reaction from arylhydrazine hydrochlorides to nitriles
-
An iodine-promoted, metal-, base-, and solvent-free cross-coupling reaction was developed for the synthesis of various useful secondary amides via an aryl N-addition reaction of aryl groups to cyano groups. This aryl transfer reaction proceeds with arylhydrazine hydrochlorides serving as the aryl donors. A labelling experiment shows that the N atom in the product comes from the cyano group of the nitriles, which are low in cost. A plausible radical-driven mechanism is also proposed.
- Zhang, Zhiguo,Li, Xiang,Li, Yinghua,Guo, Yan,Zhao, Xunan,Yan, Yan,Sun, Kai,Zhang, Guisheng
-
supporting information
p. 3628 - 3635
(2019/05/29)
-
- Catalyst-Free, Metal-Free, and Chemoselective Transamidation of Activated Secondary Amides
-
A simple protocol, which is catalyst-free, metal-free, and chemoselective, for transamidation of activated secondary amides in ethanol as solvent under mild conditions is reported. A wide range of amines, amino acids, amino alcohols, and the substituents, which are problematic in catalyzed transamidation, are tolerated in this methodology. The transamidation reaction was successfully extended to water as the medium as well. The present methodology appears to be better than the other catalyzed transamidations reported recently.
- Ramkumar, Rajagopal,Chandrasekaran, Srinivasan
-
p. 921 - 932
(2019/02/10)
-
- Copper-Catalyzed C(sp3)?H Amidation: Sterically Driven Primary and Secondary C?H Site-Selectivity
-
Undirected C(sp3)?H functionalization reactions often follow site-selectivity patterns that mirror the corresponding C?H bond dissociation energies (BDEs). This often results in the functionalization of weaker tertiary C?H bonds in the presence of stronger secondary and primary bonds. An important, contemporary challenge is the development of catalyst systems capable of selectively functionalizing stronger primary and secondary C?H bonds over tertiary and benzylic C?H sites. Herein, we report a Cu catalyst that exhibits a high degree of primary and secondary over tertiary C?H bond selectivity in the amidation of linear and cyclic hydrocarbons with aroyl azides ArC(O)N3. Mechanistic and DFT studies indicate that C?H amidation involves H-atom abstraction from R-H substrates by nitrene intermediates [Cu](κ2-N,O-NC(O)Ar) to provide carbon-based radicals R. and copper(II)amide intermediates [CuII]-NHC(O)Ar that subsequently capture radicals R. to form products R-NHC(O)Ar. These studies reveal important catalyst features required to achieve primary and secondary C?H amidation selectivity in the absence of directing groups.
- Bakhoda, Abolghasem (Gus),Jiang, Quan,Badiei, Yosra M.,Bertke, Jeffery A.,Cundari, Thomas R.,Warren, Timothy H.
-
p. 3421 - 3425
(2019/02/14)
-
- FeCl2·4H2O catalyzed ritter reaction with nitriles and halohydrocarbons
-
An efficient and inexpensive synthesis of N-substituted amides from the Ritter reaction of nitriles with various halohydrocarbons catalyzed by FeCl2·4H2O is described. FeCl2·4H2O economically efficiently catalyzed the Ritter reaction under solvent-free conditions. A range of halohydrocarbons (benzyl, tert-butyl and sec-alkyl halohydrocarbons) were coupled with nitriles to provide the corresponding amides in high to excellent yields.
- Feng, Cheng-Liang,Yin, Gui-Bo,Yan, Bin,Chen, Jun-Qing,Ji, Min
-
p. 345 - 353
(2019/02/12)
-
- Mn(III)-mediated radical cascade reaction of boronic acids with isocyanides: Synthesis of diimide derivatives
-
A manganese(III)-promoted oxidative radical cascade reaction of easily accessible arylboronic acids with isocyanides to construct diimide derivatives was studied. This protocol provides a new way to synthesis of acetyl diimide derivatives. New C–C, C–N and C[dbnd]O bonds were formed in one step.
- Wang, Fei,Wei, Tian-Qi,Xu, Pei,Wang, Shun-Yi,Ji, Shun-Jun
-
supporting information
p. 379 - 382
(2018/09/11)
-
- Metal-Free Transamidation of Secondary Amides by N-C Cleavage
-
Transamidation reactions represent a fundamental chemical process involving conversion of one amide functional group into another. Herein, we report a facile, highly chemoselective method for transamidation of N-tert-butoxycarbonylation (N-Boc) activated secondary amides that proceeds under exceedingly mild conditions in the absence of any additives. Because this reaction is performed in the absence of metals, oxidants, or reductants, the reaction tolerates a large number of useful functionalities. The reaction is compatible with diverse amides and nucleophilic amines, affording the transamidation products in excellent yields through direct nucleophilic addition to the amide bond. The utility of this methodology is highlighted in the synthesis of Tigan, a commercial antiemetic, directly from the amide bond. We expect that this new metal-free transamidation will have broad implications for the development of new transformations involving direct nucleophilic addition to the amide bond as a key step.
- Rahman, Md. Mahbubur,Li, Guangchen,Szostak, Michal
-
p. 12091 - 12100
(2019/10/11)
-
- Well-Defined, Air-Stable, and Readily Available Precatalysts for Suzuki and Buchwald-Hartwig Cross-coupling (Transamidation) of Amides and Esters by N-C/O-C Activation
-
A general class of well-defined, air-stable, and readily available Pd(II)-NHC precatalysts (NHC = N-heterocyclic carbene) for Suzuki and Buchwald-Hartwig cross-coupling of amides (transamidation) and esters by selective N-C/O-C cleavage is reported. Since these precatalysts are highly active and the easiest to synthesize, the study clearly suggests that [Pd(NHC)(acac)Cl] should be routinely included during the development of new cross-coupling methods. An assay for in situ screening of NHC salts in this cross-coupling manifold is presented.
- Zhou, Tongliang,Li, Guangchen,Nolan, Steven P.,Szostak, Michal
-
supporting information
p. 3304 - 3309
(2019/05/10)
-
- Fe(ClO 4) 3 ·h 2 O-Catalyzed Ritter Reaction: A Convenient Synthesis of Amides from Esters and Nitriles
-
An efficient and inexpensive synthesis of N-substituted amides from the Ritter reaction of nitriles with esters catalyzed by Fe(ClO 4) 3 ·H 2 O is described. Fe(ClO 4) 3 ·H 2 O is an economically efficient catalyst for the Ritter reaction under solvent-free conditions. Reactions of a range of esters (benzyl, sec-alkyl, and tert-butyl esters) with nitriles (primary, secondary, tertiary, and aryl nitriles) were performed to provide the corresponding amides in high to excellent yields.
- Feng, Chengliang,Yan, Bin,Yin, Guibo,Chen, Junqing,Ji, Min
-
p. 2257 - 2264
(2018/10/20)
-
- Oxidative C?H/C?H Cross-Coupling Reactions between N-Acylanilines and Benzamides Enabled by a Cp*-Free RhCl3/TFA Catalytic System
-
By making use of a dual-chelation-assisted strategy, a completely regiocontrolled oxidative C?H/C?H cross-coupling reaction between an N-acylaniline and a benzamide has been accomplished for the first time. This process constitutes a step-economic and highly efficient pathway to 2-amino-2′-carboxybiaryl scaffolds from readily available substrates. A Cp*-free RhCl3/TFA catalytic system was developed to replace the [Cp*RhCl2]2/AgSbF6 system generally used in oxidative C?H/C?H cross-coupling reactions between two (hetero)arenes (Cp=pentamethylcyclopentadienyl, TFA=trifluoroacetic acid). The RhCl3/TFA system avoids the use of the expensive Cp* ligand and AgSbF6. As an illustrative example, the procedure developed herein greatly streamlines the total synthesis of the naturally occurring benzo[c]phenanthridine alkaloid oxynitidine, which was accomplished in excellent overall yield.
- Shi, Yang,Zhang, Luoqiang,Lan, Jingbo,Zhang, Min,Zhou, Fulin,Wei, Wenlong,You, Jingsong
-
supporting information
p. 9108 - 9112
(2018/07/25)
-
- Synthesis, Reactivity, Functionalization, and ADMET Properties of Silicon-Containing Nitrogen Heterocycles
-
Silicon-containing compounds have been largely ignored in drug design and development, despite their potential to improve not only the potency but also the physicochemical and ADMET (absorption, distribution, metabolism, excretion, toxicity) properties of drug-like candidates because of the unique characteristics of silicon. This deficiency is in large part attributable to a lack of general methods for synthesizing diverse organosilicon structures. Accordingly, a new building block strategy has been developed that diverges from traditional approaches to incorporation of silicon into drug candidates. Flexible, multi-gram-scale syntheses of silicon-containing tetrahydroquinoline and tetrahydroisoquinoline building blocks are described, along with methods by which diversely functionalized silicon-containing nitrogen heterocycles can be rapidly built using common reactions optimized to accommodate the properties of silicon. Furthermore, to better clarify the liabilities and advantages of silicon incorporation, select compounds and their carbon analogues were challenged in ADMET-focused biological studies.
- Barraza, Scott J.,Denmark, Scott E.
-
supporting information
p. 6668 - 6684
(2018/06/12)
-
- Amide Effects in C?H Activation: Noncovalent Interactions with L-Shaped Ligand for meta Borylation of Aromatic Amides
-
A new concept for the meta-selective borylation of aromatic amides is described. It has been demonstrated that while esters gave para borylations, amides lead to meta borylations. For achieving high meta selectivity, an L-shaped bifunctional ligand has been employed and engages in an O???K noncovalent interaction with the oxygen atom of the moderately distorted amide carbonyl group. This interaction provides exceptional control for meta C?H activation/borylation.
- Bisht, Ranjana,Hoque, Md Emdadul,Chattopadhyay, Buddhadeb
-
supporting information
p. 15762 - 15766
(2018/11/10)
-
- Towards a Sequential One-Pot Preparation of 1,2,3-Benzotriazin-4(3H)-ones Employing a Key Cp*Co(III)-catalyzed C?H Amidation Step
-
1,2,3-benzotriazin-4(3H)-one derivatives have been recognised for their potential application as pesticides and pharmaceuticals and new methodologies for their preparation, starting from readily accessible reagents would therefore be an attractive proposition. A wide range of differently substituted benzamides are readily available, which provide an excellent substrate scaffold for the application of direct C?H functionalization protocols. In this context, herein we report the use of a Cp*Co(III) catalyst for the amidation of these benzamides, using 1,4,2-dioxazol-5-ones as amidating agent. The isolable intermediate 2-acetamido benzamide products can thereafter be converted to the desired 1,2,3-benzotriazin-4(3H)-one derivatives through the use of tert-butyl nitrite under mild conditions. It was found to be possible to perform the second step with the crude reaction mixture obtained from the initial C?H amidation step, leading to the overall development of a facile one-pot procedure for the preparation of a range of substituted 1,2,3-benzotriazin-4(3H)-one derivatives, requiring only 5 hours of reaction time, which is also applicable on a gram scale. In addition, the key Cp*Co(III)-catalyzed C?H amidation step has been studied by DFT calculations in order to fully elucidate the mechanism. (Figure presented.).
- Chirila, Paula G.,Skibinski, Lauren,Miller, Keith,Hamilton, Alex,Whiteoak, Christopher J.
-
supporting information
p. 2324 - 2332
(2018/04/30)
-
- Air-stable Bis(pentamethylcyclopentadienyl) Zirconium Perfluorooctanesulfonate as an Efficient and Recyclable Catalyst for the Synthesis of N-substituted Amides
-
Bis(pentamethylcyclopentadienyl) zirconium perfluorooctanesulfonate is an air-stable and water-tolerant Lewis acid. This complex exhibited good thermal stability and high solubility in polar organic solvents. The compound showed relatively strong acidity, with an acid strength of 0.8Ho≤3.3, and high catalytic efficiency for the synthesis of N-substituted amides via the reaction of carboxylic acids with amines, the Ritter reaction of nitriles with alcohols, and the amination of alcohols with amides. Moreover, the complex had good reusability. This catalytic system affords a simple and efficient way to synthesize N-substituted amides.
- Li, Ningbo,Wang, Lingxiao,Zhang, Liting,Zhao, Wenjie,Qiao, Jie,Xu, Xinhua,Liang, Zhiwu
-
p. 3532 - 3538
(2018/08/01)
-
- Convenient metal-free direct oxidative amidation of aldehyde using dibromoisocyanuric acid under mild conditions
-
A facile method for the direct synthesis of amides from aldehydes is described. Amide bonds were synthesized by an oxidative amidation in the presence of dibromoisocyanuric acid (DBI). Treatment of aromatic and aliphatic aldehydes with dibromoisocyanuric acid generated acyl bromide intermediates, which were employed to react with a variety of secondary and primary amines to give amides. Through this reaction method, various amides were synthesized directly from aldehydes under mild conditions in high yields and short times. This facile and efficient procedure provides potential strategy for the direct synthesis of amides from aldehydes.
- Kang, Soosung,La, Minh Thanh,Kim, Hee-Kwon
-
supporting information
p. 3541 - 3546
(2018/08/29)
-
- Synthesis of Amides from Alcohols and Amines Through a Domino Oxidative Amidation and Telescoped Transamidation Process
-
The amide bond formation is of paramount importance in organic synthesis, both within academic research and industrial development and manufacturing of pharmaceutical chemicals and other biologically active compounds. Despite this fact, as well as the ever-increasing treatment costs of side streams and other environmental concerns regarding handling and transportation of hazardous reagents, contemporary synthesis has elicited few new reactions and methods for the preparation of amides. Herein, we reveal a high yielding and expedite two-step telescoped synthetic process that comprises a domino oxidative amidation and transamidation for the creation of amides. The process utilizes alcohols and amines as reaction pairs with TEMPO and Fe ions as catalytic system and 1,3-dichloro-5,5-dimethyl hydantoin as a terminal oxidant. The oxidative amidation and transamidation process is conducted under benign reaction conditions and short reaction time (≈ 30 min.) in a two-step telescoped fashion by means of a multi-jet oscillating disk (MJOD) continuous-flow reactor platform. The disclosed process integrates alcohol oxidation and amide formation to afford target amide in yields up to 90 %. The method operates with both primary and secondary amines together, but was hampered when bulky amines and/or alcohols were used as reagent/substrate.
- Drageset, Audun,Bj?rsvik, Hans-René
-
p. 4436 - 4445
(2018/09/11)
-
- Convenient synthesis of amides by Zn(ClO4)2·6H2O catalysed Ritter reaction with nitriles and halohydrocarbons
-
A convenient and high yielding procedure for the synthesis of amides by the Ritter reaction of nitriles and halohydrocarbons in the presence of Zn(ClO4)2·6H2O as a highly stable, effective and available catalyst is described.
- Feng, Chengliang,Yin, Guibo,Yan, Bin,Chen, Junqing,Ji, Min
-
supporting information
p. 383 - 386
(2018/08/21)
-
