20826-48-6Relevant academic research and scientific papers
Effect of ligand and bridge substitution on chiral recognition of 1-phenylethylammonium cation by an anionic binuclear Ni(II) complex
Das, Chandani Rani,Dutta, Tanmay,Ray, Manabendra
, p. 367 - 376 (2019)
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
Simultaneous chirality sensing of multiple amines by 19F NMR
Zhao, Yanchuan,Swager, Timothy M.
, p. 3221 - 3224 (2015)
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.
A dual-catalysis anion-binding approach to the kinetic resolution of amines: Insights into the mechanism via a combined experimental and computational study
Mittal, Nisha,Lippert, Katharina M.,De, Chandra Kanta,Klauber, Eric G.,Emge, Thomas J.,Schreiner, Peter R.,Seidel, Daniel
, p. 5748 - 5758 (2015)
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
Three-Component Iminolactonization Reaction via Bifunctionalization of Olefins Using Molecular Iodine and Visible Light
Itoh, Akichika,Maejima, Saki,Yamaguchi, Eiji
, p. 10709 - 10718 (2020)
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.
AMINE-BORANES AS BIFUNCTIONAL REAGENTS FOR DIRECT AMIDATION OF CARBOXYLIC ACIDS
-
Paragraph 0008-0009; 0063-0064, (2022/03/04)
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.
Generation of Oxyphosphonium Ions by Photoredox/Cobaloxime Catalysis for Scalable Amide and Peptide Synthesis in Batch and Continuous-Flow
Chen, Xiangyang,Houk, Kendall N.,Mo, Jia-Nan,Su, Junqi,Umanzor, Alexander,Zhang, Zheng,Zhao, Jiannan
supporting information, (2022/01/06)
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
Chiral separation materials based on derivatives of 6-amino-6-deoxyamylose
Gao, Ya-Ya,Zhang, Yu-Hang,Zhang, Shan,Chen, Wei,Bai, Zheng-Wu
supporting information, p. 899 - 914 (2021/10/07)
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.
Direct enantioseparation of axially chiral 1,1′-biaryl-2,2′-diols using amidine-based resolving agents
Hirose, Takuji,Kodama, Koichi,Takase, Fusato
, p. 18162 - 18170 (2021/06/07)
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.
Design and synthesis of 3,3′-triazolyl biisoquinoline N,N’-dioxides via Hiyama cross-coupling of 4-trimethylsilyl-1,2,3-triazoles
Sun, Shiyu,Reep, Carlyn,Zhang, Chenrui,Captain, Burjor,Peverati, Roberto,Takenaka, Norito
, (2021/09/16)
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.
Carboxyesterase polypeptides for amide coupling
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Page/Page column 63-64; 68-72; 79-81, (2021/05/28)
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.
