- Enantioselective Reductive Cyanation and Phosphonylation of Secondary Amides by Iridium and Chiral Thiourea Sequential Catalysis
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The combination of transition-metal catalysis and organocatalysis increasingly offers chemists opportunities to realize diverse unprecedented chemical transformations. By combining iridium with chiral thiourea catalysis, direct enantioselective reductive cyanation and phosphonylation of secondary amides have been accomplished for the first time for the synthesis of enantioenriched chiral α-aminonitriles and α-aminophosphonates. The protocol is highly efficient and enantioselective, providing a novel route to the synthesis of optically active α-functionalized amines from the simple, readily available feedstocks. In addition, the reactions are scalable and the thiourea catalyst can be recycled and reused.
- Chen, Dong-Huang,Sun, Wei-Ting,Zhu, Cheng-Jie,Lu, Guang-Sheng,Wu, Dong-Ping,Wang, Ai-E,Huang, Pei-Qiang
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supporting information
p. 8827 - 8831
(2021/03/16)
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- Manganese(III) Porphyrin-Catalyzed Dehydrogenation of Alcohols to form Imines, Tertiary Amines and Quinolines
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Manganese(III) porphyrin chloride complexes have been developed for the first time as catalysts for the acceptorless dehydrogenative coupling of alcohols and amines. The reaction has been applied to the direct synthesis of imines, tertiary amines and quinolines where only hydrogen gas and/or water are formed as the by-product(s). The mechanism is believed to involve the formation of a manganese(III) alkoxide complex which degrades into the aldehyde and a manganese(III) hydride species. The latter reacts with the alcohol to form hydrogen gas and thereby regenerates the alkoxide complex.
- Azizi, Kobra,Akrami, Sedigheh,Madsen, Robert
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p. 6439 - 6446
(2019/04/26)
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- Monocyclic β-lactam and unexpected oxazinone formation: synthesis, crystal structure, docking studies and antibacterial evaluation
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Novel monocyclic β-lactam derivatives bearing aryl, phenyl and heterocyclic rings were synthesized as possible antibacterial agents. Cyclization of imines (3h, 3t) with phenylacetic acid in the presence of phosphoryl chloride and triethyl amine did not afford the expected β-lactams. Instead, highly substituted 1,3-oxazin-4-ones (4h, 4t) were isolated as the only product and confirmed by single crystal X-ray analysis of 4t. The results of antibacterial activity showed that compound 4l exhibited considerable antibacterial activity with MIC and MBC values of 62.5 μg/mL against Klebsiella pneumoniae. Cytotoxicity assay on Chinese Hamster Ovary (CHO) cell line revealed non-cytotoxic behavior of compounds 4d, 4h, 4k and 4l up to 200 μg/mL conc. Molecular docking was performed for compound 4l with penicillin binding protein-5 to identify the nature of interactions. The results of both in silico and in vitro evaluation provide the basis for compound 4l to be carried as a potential lead molecule in the drug discovery pipeline against bacterial infections.
- Aneja, Babita,Irfan, Mohammad,Hassan, Md. Imtaiyaz,Prakash, Amresh,Yadava, Umesh,Daniliuc, Constantin G.,Zafaryab, Md.,Rizvi, M. Moshahid A.,Azam, Amir,Abid, Mohammad
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p. 834 - 852
(2016/07/07)
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- A one-pot synthesis of highly substituted tetrahydropyridines from N-benzylidenemethanamines, dialkyl acetylenedicarboxylates and benzylidenemalononitriles
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A simple and efficient synthesis of highly substituted tetrahydropyridines has been develope using a one-pot, two step reactions. The synthesis of a series of N-benzylidenemethanamine from benzylamines and benzaldehydes in the presence of acetic acid, followed by cyclizatio with dialkyl acetylenedicarboxylates and benzylidenemalononitriles, gave the correspondin tetrahydropyridines in good yields.
- Mehrabi, Hossein,Mohebbi, Ahmad
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- Factors influencing the regioselectivity of the oxidation of asymmetric secondary amines with singlet oxygen
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Aerobic amine oxidation is an attractive and elegant process for the α functionalization of amines. However, there are still several mechanistic uncertainties, particularly the factors governing the regioselectivity of the oxidation of asymmetric secondary amines and the oxidation rates of mixed primary amines. Herein, it is reported that singlet-oxygen-mediated oxidation of 1° and 2° amines is sensitive to the strength of the α-C-H bond and steric factors. Estimation of the relative bond dissociation energy by natural bond order analysis or by means of one-bond C-H coupling constants allowed the regioselectivity of secondary amine oxidations to be explained and predicted. In addition, the findings were utilized to synthesize highly regioselective substrates and perform selective amine cross-couplings to produce imines.
- Ushakov, Dmitry B.,Plutschack, Matthew B.,Gilmore, Kerry,Seeberger, Peter H.
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supporting information
p. 6528 - 6534
(2015/04/22)
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- Development of novel vitamin D receptor-coactivator inhibitors
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Nuclear receptor coregulators are master regulators of transcription and selectively interact with the vitamin D receptor (VDR) to modulate cell differentiation, cell proliferation, and calcium homeostasis. Herein, we report the syntheses and evaluation of highly potent and selective VDR-coactivator inhibitors based on a recently identified 3-indolylmethanamine scaffold. The most active compound, PS121912, selectively inhibited VDR-mediated transcription among eight other nuclear receptors tested. PS121912 is also selectively disrupting the binding between VDR and the third nuclear receptor interaction domain of the coactivator SRC2. Genetic studies revealed that PS121912 behaves like a VDR antagonist by repressing 1,25-(OH)2D3 activated gene transcription. In addition, PS121912 induced apoptosis in HL-60.
- Sidhu, Preetpal S.,Nassif, Nicholas,McCallum, Megan M.,Teske, Kelly,Feleke, Belaynesh,Yuan, Nina Y.,Nandhikonda, Premchendar,Cook, James M.,Singh, Rakesh K.,Bikle, Daniel D.,Arnold, Leggy A.
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supporting information
p. 199 - 204
(2014/03/21)
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- General, green, and scalable synthesis of imines from alcohols and amines by a mild and efficient copper-catalyzed aerobic oxidative reaction in open air at room temperature
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A general, green, and scalable synthesis of the useful imines and a,b-unsaturated imines is successfully achieved by a low-loading and powerful, mild and efficient copper-catalyzed aerobic oxidative reaction of alcohols and amines in the open air at room temperature under base- and dehydrating reagent-free conditions. This practical reaction can use air as the economic and green oxidant, tolerates a wide range of substrates, can afford high yields of the target imines on a large scale, and produces water as the only by-product, and thus being the best imination method as yet using alcohols and amines directly.
- Tian, Haiwen,Yu, Xiaochun,Li, Qiang,Wang, Jianxin,Xu, Qing
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supporting information
p. 2671 - 2677,7
(2012/12/12)
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- Use of Quantitative Structure - Activity Relationship (QSAR) and ADMET prediction studies as screening methods for design of benzyl urea derivatives for anti-cancer activity
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2D and 3D quantitative structure-activity relationship studies have been carried out for establishing a correlation between the structural properties of benzyl urea derivatives and their anti-tumour activities. From this correlation, the new chemical entities were designed, and their activity and absorption, distribution, metabolism, excretion, and toxicity properties were also predicted. Finally, the most promising compounds from these screening were synthesized and biologically evaluated for their anti-cancer properties. Compound 1-(2, 4-dimethylphenyl)-3, 3-dimethyl-1-(2-nitrobenzyl) urea (7d) showed significant anti-proliferative activity (at 100 μg/mL) in human cancer cell lines-T-cell leukemia (Jurkat J6), myelogenous leukemia (K562), and breast cancer (MCF-7) compared to reference standard 5-flurouracil.
- Lokwani, Deepak,Bhandari, Shashikant,Pujari, Radha,Shastri, Padma,Shelke, Ganesh,Pawar, Vidya
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experimental part
p. 319 - 331
(2012/02/14)
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- Highly enantioselective titanium-catalyzed cyanation of imines at room temperature
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(Figure presented) A highly active and enantioselective titanium-catalyzed cyanatlon of imines at room temperature Is described. The catalyst used Is a partially hydrolyzed titanium alkoxide (PHTA) precatalyst together with a readily available N-salicyl-β-aminoalcohol ligand. Up to 98% ee was obtained with quantitative yields In 15 min of reaction time using 5 mol % of the catalyst. Various N-protecting groups such as benzyl, benzhydryl, Boc, and PMP are tolerated.
- Seayad, Abdul Majeed,Ramalingam, Balamurugan,Yoshinaga, Kazuhiko,Nagata, Takushi,Chai, Christina L. L.
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supporting information; experimental part
p. 264 - 267
(2010/03/24)
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