7244-67-9Relevant academic research and scientific papers
Transamidation and Decarbonylation of N-Phthaloyl-Amino Acid Amides Enabled by Palladium-Catalyzed Selective C–N Bond Cleavage
Zhang, Hao-Yu,Tao, Xuan-Wen,Yi, Li-Na,Zhao, Zhi-Gang,Yang, Qiang
, p. 231 - 242 (2022/01/11)
Amides are important functional synthons that have been widely used in the construction of peptides, natural products, and drugs. The C–N bond cleavage provides the direct method for amide conversion. However, amides, especially secondary amides, tend to
Green Esterification of Carboxylic Acids Promoted by tert-Butyl Nitrite
Cheng, Xionglve,Jiang, Gangzhong,Li, Xingxing,Tao, Suyan,Wan, Xiaobing,Zhao, Yanwei,Zheng, Yonggao
supporting information, p. 2713 - 2718 (2021/06/25)
In this work, the green esterification of carboxylic acids promoted by tert-butyl nitrite has been well developed. This transformation is compatible with a broad range of substrates and exhibits excellent functional group tolerance. Various drugs and substituted amino acids are applicable to this reaction under near neutral conditions, with good to excellent yields.
Amide Synthesis by Nickel/Photoredox-Catalyzed Direct Carbamoylation of (Hetero)Aryl Bromides
Alandini, Nurtalya,Buzzetti, Luca,Candish, Lisa,Collins, Karl D.,Favi, Gianfranco,Melchiorre, Paolo,Schulte, Tim
supporting information, p. 5248 - 5253 (2020/03/03)
Herein, we report a one-electron strategy for catalytic amide synthesis that enables the direct carbamoylation of (hetero)aryl bromides. This radical cross-coupling approach, which is based on the combination of nickel and photoredox catalysis, proceeds at ambient temperature and uses readily available dihydropyridines as precursors of carbamoyl radicals. The method's mild reaction conditions make it tolerant of sensitive-functional-group-containing substrates and allow the installation of an amide scaffold within biologically relevant heterocycles. In addition, we installed amide functionalities bearing electron-poor and sterically hindered amine moieties, which would be difficult to prepare with classical dehydrative condensation methods.
Electrochemical anion pool synthesis of amides with concurrent benzyl ester synthesis
Mevan Dissanayake,Melville, Alex D.,Vannucci, Aaron K.
supporting information, p. 3165 - 3171 (2019/06/18)
An electrosynthesis method for amide bond formation has been developed in an attempt to increase the atom economy for this class of reactions. This "anion pool" method electrochemically generates strong nucleophiles from amine substrates. The amine nucleophiles then react with acid anhydrides to generate amides, and the by-product from this reaction undergoes further chemical transformations to generate pharmaceutically relevant benzoic esters. These one-pot reactions are operationally simple, are performed at room temperature, and avoid rare transition metals and added bases. The amide synthesis is amenable to primary and secondary amines and a variety of anhydrides with yields up to 90% obtained. Atom economy and process mass index (PMI) values calculated for this procedure indicate that this process can be considered greener compared to traditional amide synthesis routes used by industry. Furthermore, this electrochemical approach showed unique selectivity when substrates that contained two inequivalent amine moieties were examined.
Formation of Non-Natural α,α-Disubstituted Amino Esters via Catalytic Michael Addition
Teegardin, Kip A.,Gotcher, Lacey,Weaver, Jimmie D.
supporting information, p. 7239 - 7244 (2018/11/25)
The enolate monoanion of amino esters is explored, and the first catalytic Michael addition of α-amino esters is demonstrated. These studies indicate that the acidity of the αC-H is the primary factor determining reactivity. Thus, polyfluorophenylglycine amino esters yield novel α-amino esters in the presence of a catalytic amount of a guanidine-derived base and Michael acceptors. Reactivity requires an acidic N-H, which is accomplished using common protecting groups such as N-Bz, N-Boc, and N-Cbz. Calculations and labeling experiments provide insight into the governing principles in which a key C-to-N proton transfer occurs, resulting in an expansion of the scope to include a number of natural amino esters. The study culminates with a late-stage functionalization of peptidic γ-secretase inhibitor, DAPT.
Microwave-Assisted Ruthenium-Catalysed ortho-C?H Functionalization of N-Benzoyl α-Amino Ester Derivatives
Sharma, Nandini,Bahadur, Vijay,Sharma, Upendra K.,Saha, Debasmita,Li, Zhenghua,Kumar, Yogesh,Colaers, Jona,Singh, Brajendra K,Van der Eycken, Erik V.
supporting information, p. 3083 - 3089 (2018/08/24)
A microwave-assisted highly efficient intermolecular C?H functionalization sequence has been developed to access substituted isoquinolones using α-amino acid esters as a directing group. This methodology enables a wide range of N-benzoyl α-amino ester derivatives to react via a Ru-catalysed C?H bond activation sequence, to form isoquinolones with moderate to excellent yields. As an additional advantage, our strategy proved to be widely applicable and also enabled the reaction of alkenes to provide access to alkenylated benzamides. The methodology was also extended towards the synthesis of isoquinoline alkaloids derivatives viz. oxyavicine and a dipeptide. The developed protocol is simple and cheap, avoids tedious workup procedures and works efficiently under MW irradiation. (Figure presented.).
Synthesis of Hydrazones from Amino Acids and their Antimicrobial and Cytotoxic Activities
Abid, Obaid-Ur-Rahman,Khatoon, Ghamama,Arfan, Muhammad,Sajid, Imran,Langer, Peter,Rehman, Wajid,Rahim, Fazal,Yasir, Muhammad,Waqar, Muhammad,Haleem, Kashif Syed
, p. 1079 - 1087 (2017/09/26)
Hydrazones 6a–6n were synthesized from different amino acids with various aldehydes under reflux in methanol/ethanol. The structures of synthesized compounds were ascertained by elemental analysis and spectroscopic techniques. A comparative study of the antimicrobial activity and cytotoxicity was carried out of the N-protected amino acids, their esters, hydrazides, and the respective hydrazones, providing good results in cytotoxicity studies.
Regiodivergent Enantioselective γ-Additions of Oxazolones to 2,3-Butadienoates Catalyzed by Phosphines: Synthesis of α,α-Disubstituted α-Amino Acids and N,O-Acetal Derivatives
Wang, Tianli,Yu, Zhaoyuan,Hoon, Ding Long,Phee, Claire Yan,Lan, Yu,Lu, Yixin
, p. 265 - 271 (2016/01/25)
Phosphine-catalyzed regiodivergent enantioselective C-2- and C-4-selective γ-additions of oxazolones to 2,3-butadienoates have been developed. The C-4-selective γ-addition of oxazolones occurred in a highly enantioselective manner when 2-aryl-4-alkyloxazol-5-(4H)-ones were employed as pronucleophiles. With the employment of 2-alkyl-4-aryloxazol-5-(4H)-ones as the donor, C-2-selective γ-addition of oxazolones took place in a highly enantioselective manner. The C-4-selective adducts provided rapid access to optically enriched α,α-disubstituted α-amino acid derivatives, and the C-2-selective products led to facile synthesis of chiral N,O-acetals and γ-lactols. Theoretical studies via DFT calculations suggested that the origin of the observed regioselectivity was due to the distortion energy that resulted from the interaction between the nucleophilic oxazolide and the electrophilic phosphonium intermediate.
Light-enabled synthesis of anhydrides and amides
Mccallum, Terry,Barriault, Louis
, p. 2874 - 2878 (2015/03/30)
Recently, we have demonstrated that the photogeneration of Vilsmeier-Haack reagents is possible using only dimethylformamide (DMF) and tetrabromomethane (CBr4) in the bromination of alcohols. Extending these findings to carboxylic acid substrates has produced a mild and facile approach to the in situ formation of symmetric anhydrides, which were conveniently converted to amide derivatives in a one-pot process. The efficient protocols discussed herein are marked by use of UVA LEDs (365 nm), which have reduced the reaction times and come with a low setup cost.
N-heterocyclic carbene-catalyzed oxidative amidation of aldehydes with amines
Alanthadka, Anitha,Maheswari, C. Uma
supporting information, p. 1199 - 1203 (2015/04/22)
The N-heterocyclic carbene (NHC)-catalyzed oxidative amidation of aromatic aldehydes with amines in the presence of N-bromosuccinimide (NBS) as an oxidant has been developed for the synthesis of amides. This amidation strategy is tolerant to both the electronic and the steric nature of the aryl aldehydes employed. The present methodology was extended to chiral amino acid derivatives to generate the corresponding amides in good yields and excellent ee values (>98%).
