- Base controlled three-component regioselective synthesis of 2-imino thiazolines and 2-thioxoimidazolin-4-ones
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Base-controlled regioselective synthesis of 2-imino thiazolines and 2-thioxoimidazolin-4-ones was achieved to use a one-pot reaction between chiral amino esters, isothiocyanates, and α-bromoketones/alkyl halides. This three-component coupling reaction in acetonitrile provides 2-imino thiazolines, whereas the formation of 2-thioxoimidazolin-4-ones was observed under basic conditions at ambient temperature. The corresponding products were obtained in good to excellent yield with broad substrate scope. Isolation of thiourea and thiohydantoin intermediates disclosed the course of the reaction mechanism.
- Barve, Indrajeet J.,Chang, Wong-Jin,Lin, Yen-Tzu,Thikekar, Tushar Ulhas,Sun, Chung-Ming
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- Asymmetric Synthesis of Adjacent Tri- and Tetrasubstituted Carbon Stereocenters: Organocatalytic Aldol Reaction of an Hydantoin Surrogate with Azaarene 2-Carbaldehydes
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A bifunctional amine/squaramide catalyst promoted direct aldol addition of an hydantoin surrogate to pyridine 2-carbaldehyde N-oxides to afford adducts bearing two vicinal tertiary/quaternary carbons in high diastereo- and enantioselectivity (d.r. up to >20:1; ee up to 98 %) is reported. Acid hydrolysis of adducts followed by reduction of the N-oxide group yields enantiopure carbinol-tethered quaternary hydantoin-azaarene conjugates with densely functionalized skeletons. DFT studies of the potential energy surface (B3LYP/6–31+G(d)+CPCM (dichloromethane)) of the reaction correlate the activity of different catalysts and support an intramolecular hydrogen-bond-assisted activation of the squaramide moiety in the transition state of the catalytic reaction.
- Izquierdo, June,Demurget, Noémie,Landa, Aitor,Brinck, Tore,Mercero, Jose M.,Dinér, Peter,Oiarbide, Mikel,Palomo, Claudio
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supporting information
p. 12431 - 12438
(2019/09/17)
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- Enantioselective Synthesis of 5,5-Disubstituted Hydantoins by Br?nsted Base/H-Bond Catalyst Assisted Michael Reactions of a Design Template
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A new method for the enantioselective synthesis of 5,5-disubstituted (quaternary) hydantoins was developed on the basis of an organocatalytic Michael reaction approach involving the use of 2-benzylthio-3,5-dihydroimidazol-4-ones as key hydantoin surrogates. The method is general with respect to the substitution pattern at the hydantoin N1 (alkyl, aryl, acyl), N3 (aryl), and C5 (linear/branched alkyl, aryl) positions and affords essentially single diastereomeric products with enantioselectivities higher than 95 % ee in most cases. Among the bifunctional Br?nsted base/H-bond catalysts examined, a known squaramide–tertiary amine catalyst and a newly prepared squaramide–tertiary amine catalyst provide the highest selectivity so far with either nitroolefins or vinyl ketones as the acceptor components. Kinetic measurements support a first-order rate dependence on both reaction partners, the donor template and the Michael acceptor, whereas competitive 1H NMR spectroscopy experiments reveal the high ability of the template for catalyst binding.
- Izquierdo, Joseba,Etxabe, Julen,Du?abeitia, Eider,Landa, Aitor,Oiarbide, Mikel,Palomo, Claudio
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supporting information
p. 7217 - 7227
(2018/05/04)
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- Microwave assisted synthesis of 1,3,4-oxadiazole/thiohydantoin hybrid derivatives via dehydrative cycliztion of semicarbazide
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A series of compounds containing both 1,3,4-oxadiazole and thiohydantoin were synthesized as a promising scaffold for application in medicinal chemistry. The key step of the synthesis is a microwave-assisted cyclization of semicarbazides possessing a thiohydantoin moiety at one of the acyl termini using POCl3 as a dehydrating reagent. A wide range of semicarbazides were prepared through the substitution of hydrazides with an N-acylated thiohydantoin derived from the cyclization of the corresponding isothiocyanate with an amino acid and subsequent N-acylation of the resultant thiohydrantion. Consequently, the 58 number of 1,3,4-oxadiazole derivatives having a thiohydantoin substituent were prepared in good overall yields. Thiohydantoin 134-Oxadiazole Semicarbazide Microwave Amino acid Acknowledgments. This research was conducted under the Industrial Infrastructure Program for Fundamental Technologies and Institute for Advancement of Technology through the Inter-ER Cooperation Projects (R0002016) which are funded by the Ministry of Trade, Industry & Energy, Korea to YDG and Open Translational Research Center for Innovative Drug (2012M3A9C1053532) which are funded by National Research Foundation of Korea.
- Yang, Seung-Ju,Lee, Jae-Min,Lee, Gee-Hyung,Kim, NaYeon,Kim, Yong-Sang,Gong, Young-Dae
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p. 3609 - 3617
(2015/02/05)
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- An efficient method for synthesis of thiohydantoins with α-amino esters under microwave irradiation
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An efficient and simple way for synthesis of thiohydantoins is reported. In the absence of any additional catalysts, a series of thiohydantoins were synthesized with amino esters and isothiocyanates in aqueous medium under microwave irradiation. Excellent isolated yields (up to 98 %) were obtained under mild conditions.
- Zhao, Yanmei,Wang, Zhouyu,Jiang, Zhenju,Feng, Hualin,Liu, Li,Wang, Ju
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p. 1171 - 1173
(2014/06/09)
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- Highly efficient dehydrogenation of 5-benzyl-3-phenyl-2-thioxoimidazolidin- 4-one: Microwave versus flash vacuum pyrolysis conditions
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5-Benzyl-3-phenyl-2-thioxoimidazolidin-4-one underwent thermal dehydrogenation to afford 5-benzylidene-2-thioxoimidaxolidin-4-one under microwave and flash vacuum pyrolysis conditions. A high predominance of the Z-isomer over the E-isomer of the imidazolidinone product was achieved. By using DFT and NBO calculations, the mechanism of the dehydrogenation and the selectivity were also explored. In this article we report the dehydrogenation reaction of a benzylthioxoimidazolidinone derivative by using two unconventional and solvent-free methodologies: flash vacuum pyrolysis and microwave-induced pyrolysis. DFT calculations were performed to understand the dehydrogenation mechanism and to explain the high selectivity achieved towards the formation of the Z-isomer.
- Pepino, Ana J.,Pelaez, Walter J.,Moyano, Elizabeth L.,Argueello, Gustavo A.
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experimental part
p. 3424 - 3430
(2012/08/08)
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- Microwave-assisted synthesis of 3,5-disubstituted thiohydantoins using functional ionic liquid as soluble support
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A new approach for the syntheses of 3,5-disubstituted thiohydantoins was described using functionalized ionic liquid as soluble support. The products were obtained in good yields and purities after cyclization-cleavage from the ionic-liquid-supported under microwave irradiation, the ionic-liquid-supported species can there be purified from the reaction mixture by simple washing, and no chromatographic purification were needed during the synthesis. The Japan Institute of Heterocyclic Chemistry.
- Zhuo, Chen,Xian, Dong,Hui, Xie,Mei, Li
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p. 1121 - 1127
(2011/06/17)
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- Hydrogen bonded dimers vs. one-dimensional chains in 2-thiooxoimidazolidin- 4-one (thiohydantoin) drug derivatives
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Hydantoins have been known as medicinally active compounds since the 1940s and thiohydantoin derivatives are currently undergoing clinical trials as potent androgen receptor antagonist drugs. Control of solid state properties including the formation of drug polymorphs is important to the pharmaceutical industry, and frequently results from different H-bonded motifs. N-H thiohydantoins show formation of H-bonded arrays in the solid state. Two novel and five known thiohydantoin derivatives were synthesised via reaction of alkyl isothiocyanates with amino acid methyl esters. X-Ray crystallographic data were obtained for all seven compounds showing that four of the structures contain hydrogen bonded dimeric units linked via N-H...S interactions and three of the structures have N-H...O linked H-bonded chains. The Royal Society of Chemistry 2010.
- Jha, Sushil,Silversides, Jon D.,Boyle, Ross W.,Archibald, Stephen J.
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experimental part
p. 1730 - 1739
(2011/12/02)
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- Method for inhibition of HIV related viruses
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Treatment of AIDS, inhibition of the replication of HIV and related viruses thereof, and formulations using thiourea derivative compounds or salts thereof is disclosed. Also disclosed are novel thiourea derivative compounds.
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