10.1081/SCC-100107009
The research focuses on the synthesis of aryl or benzyl-(Z)-N-[2-amino-1,2dicyanovinyl]formamidines, which are significant compounds acting as intermediates in various biological processes. The study describes a method to prepare these amidines by reacting ethyl(Z)-N-(2-amino-1,2dicyanovinyl)formimidate (1) with aromatic amines at room temperature in the presence of a catalytic amount of anilinium hydrochloride. The reactants include ethyl(Z)-N-(2-amino-1,2-dicyanovinyl)formimidate and various aryl or benzylamines. The analysis of the synthesized products involved techniques such as thin-layer chromatography (TLC), 1H and 13C NMR spectroscopy, mass spectrometry, and infrared spectroscopy, which confirmed the structure and purity of the compounds. The elemental analysis results were also satisfactory, and the mass spectra showed characteristic peaks for each product. The 1H NMR spectra revealed interesting features such as the coupling of benzylic protons to the NH proton, and the infrared spectra displayed strong absorption bands characteristic of CN stretching vibrations, along with NH and C?N stretching vibrations.
10.1016/j.tetlet.2008.01.038
The research focuses on the stereomeric studies of the oxidation and alkylation of 4-thiazolidinones, which are important cores in biologically active compounds with potential anti-inflammatory, antibacterial, anticancer activities, and other therapeutic properties. The study investigates diastereoselectivity in the oxidation of various 4-thiazolidinones to sulfoxides and sulfones, and the subsequent alkylation of these compounds with benzyl bromide. The experiments involved synthesizing different 4-thiazolidinones using aldehydes, benzylamine, and mercaptoacetic acid, followed by optimizing oxidation conditions to achieve high yields without overoxidation. The diastereoselectivity of the oxidation products was analyzed using HPLC and 1H NMR, with the best conditions found using AcOOH as the oxidant. The alkylation reactions were optimized using various bases, temperatures, and reaction times, with NaH found to be the most effective base. The stereoselectivity of the alkylation products was determined by HPLC and X-ray crystallography, revealing that the sulfoxide group influences the selectivity and that the substituent at carbon 5 and the sulfoxide are in a cis conformation.
10.1080/00397910008086885
The research details a versatile approach to synthesizing protected (S)-aspartimide, (4S)-amino-2-pyrrolidinone, and (3S)-aminopyrrolidine derivatives starting from (S)-aspartic acid. The purpose of this study was to develop a unified method for these structurally related compounds, which are significant due to their presence in various bioactive compounds and their potential use as chiral ligands in asymmetric synthesis. The researchers successfully synthesized (S)-1-benzyl-3-p-toluenesulfonylamino-2,5-pyrrolidinedione, (S)-1-benzyl-3-p-toluenesulfonylaminopyrrolidine, and (S)-1-benzyl-4-p-toluenesulfonylamino-2-pyrrolidinone using a series of reactions involving tosylation, cyclization, and selective reductions. Key chemicals used in the process included (S)-aspartic acid, acetic anhydride, benzylamine, lithium aluminium hydride, sodium borohydride, and various solvents such as ethyl acetate and tetrahydrofuran (THF). The study concluded with the establishment of a useful approach to these compounds, which are valuable building blocks for several bioactive compounds, and noted that further investigation into the use of the synthesized compounds as chiral ligands for asymmetric synthesis is underway.
10.1002/ejoc.200900088
The study presents a novel and efficient method for synthesizing Vitamin E amines (tocopheramines and tocotrienamines) in enantiopure form. These compounds are significant due to their potential biological and antioxidant properties, making them valuable for applications in food additives, polymer stabilizers, and pharmaceuticals. The synthesis involves Pd-catalyzed N-arylation reactions on triflates derived from the corresponding phenols. Key chemicals used include Pd(OAc)2 and rac-BINAP as catalysts, NaOtBu or Cs2CO3 as bases, and benzylamine or benzophenone imine as nitrogen sources. The process involves converting natural tocopherols and tocotrienols into their triflate derivatives, followed by amination to introduce the nitrogen function at the 6-position of the chromane ring. The study optimizes the reaction conditions to achieve high yields and purity of the final products, demonstrating a significant improvement over previous methods. The synthesized compounds are of interest for further investigation into their antioxidant and therapeutic properties, with preliminary results showing promising antiproliferative effects on cancer cell lines.
10.1055/s-0028-1087950
The research presents the synthesis of novel chiral ionic liquids (CILs) based on L-(+)-tartaric acid, leveraging its low cost and renewability as a chiral pool source. The study's main content involves a two-step synthesis strategy: first, reacting L-tartaric acid with benzylamine to form pyrrolidindione, followed by reduction with LiAlH4 to obtain benzylpyrrolidine. Subsequent quaternization with benzyl or n-dodecyl bromide under conventional or microwave heating yielded the desired chiral pyrrolidinium salts. The synthesized compounds were characterized by their melting points, and anion exchange was performed to obtain different ionic liquids. The researchers also examined the crystallographic structures of selected compounds to understand the absence of hydrogen-bonding interactions between cations, which contributed to the reduced melting points. The chiral recognition ability of these ionic materials was evaluated through NMR spectroscopy, observing the interaction between the synthesized cations and Mosher acid anion, which indicated the formation of diastereomeric salts. This research provides a foundation for further investigation into the potential of these CILs as solvents, catalysts, or ligands in asymmetric synthesis.
10.1016/j.bmcl.2017.09.023
The research focuses on the discovery of highly potent and selective covalent inhibitors of JAK3, a key enzyme in the immune system. The study is based on the design of molecules that bind irreversibly to the JAK3 active site cysteine residue, utilizing crystal structure information and a comparative study of electrophilic warheads. Experiments involved the synthesis of compounds, such as 9a and 9b, and their evaluation for JAK3 inhibition through enzymatic assays, cellular assays, and kinome selectivity screens. Reactants used in the synthesis included intermediates like meta-nitro benzylamine and aniline, which were subjected to hydrogenolysis and acylation to produce the final compounds. The analyses used to assess the compounds' potency and selectivity included fixed time point enzymatic assays, cellular potency assays, and broad kinome selectivity screens against over 350 kinases. The results indicated that 9a was a highly potent JAK3 inhibitor with excellent selectivity, while further exploration of alternative electrophilic groups in the pyrazolopyridazine series led to the identification of 13a, which confirmed covalent interaction with Cys909 in the JAK3 active site through X-ray crystallography and kinetic evaluation.
10.1016/j.tet.2008.09.043
This research presents an efficient method for the synthesis of 5-amino?avones, an important class of natural compounds within the ?avonoid group known for their various biological activities such as antiestrogenic, antitumor, antiallergic, and antiin?ammatory properties. The authors developed a microwave-assisted SNAr (Nucleophilic Aromatic Substitution) reaction to access 5-amino?avones, which allows for the introduction of an amino group directly onto the ?avone nucleus, a less commonly reported approach. The process involves the protection of diosmetin with benzyl bromide, followed by tri?ation and amination using various amines. The study concluded that this methodology yields good results with primary and secondary non-aromatic amines and even moderate yields with anilines, without the need for palladium catalysts or hard bases. Key chemicals used in the process include diosmetin, benzyl bromide, N-phenylbistri?imide (PhNTf2), and a range of amines such as benzylamine and its derivatives, as well as primary alkylamines and cycloalkylamines. The final step involved the removal of protective benzyl groups through catalytic hydrogenation to yield the final 5-amino?avone compounds.
10.1021/acs.joc.0c00542
The research focuses on the development of an efficient method for the synthesis of seven-membered biaryl lactams through a Pd-catalyzed, native amine-directed ortho-arylation of benzylamines followed by in situ lactamization. This one-pot cascade reaction employs 2-iodobenzoates and is characterized by a broad substrate scope and good functional group tolerance. The study explores the use of ester versus carboxylic acid-functionalized coupling partners and investigates the potential for synthesizing eight-membered biaryl lactams. The researchers successfully demonstrated the versatility of the method, which includes the synthesis of various biaryl lactams and their derivatives, and potential applications in natural product synthesis, such as accessing the aza-brassinolide core. Key chemicals used in the process include Pd(OAc)2 as a catalyst, AgOAc as an additive, and a variety of benzylamines and 2-iodobenzoate esters as substrates. The conclusions highlight the robustness of the protocol, which works with α-tertiary, α-secondary, and α-primary amines, and its potential use as an entry into natural product synthesis, without the need for CO2 or other transient directing groups.
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