- Facile and odorless one-pot process for the synthesis of N-substituted thioamides via TsCl-mediated Beckmann rearrangement of ketoximes
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A facile and odorless one-pot thionation process for the synthesis of N-substituted thioamides using chemically stable and inexpensive thiourea reagent via the Beckmann rearrangement of ketoximes, has been described. Georg Thieme Verlag Stuttgart · New York.
- Liu, Li-Feng,An, Na,Pi, Hong-Jun,Ying, Jun,Du, Wenting,Deng, Wei-Ping
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- Ketoximes to N-substituted thioamides via PSCl3 mediated Beckmann rearrangement
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N-Substituted thioamides were accessed from ketoximes by utilising PSCl3 as a uniquely capable reagent to induce Beckmann rearrangement as well as to capture the intermediate nitrilium ion. The Royal Society of Chemistry 2009.
- Pathak, Uma,Pandey, Lokesh Kumar,Mathur, Sweta,Suryanarayana
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- Contribution of Solvents to Geometrical Preference in the Z/ E Equilibrium of N-Phenylthioacetamide
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We studied the Z/E preference of N-phenylthioacetamide (thioacetanilide) derivatives in various solvents by means of 1H NMR spectroscopy, as well as molecular dynamics (MD) and other computational analyses. Our experimental results indicate that the Z/E isomer preference of secondary (NH)thioamides of N-phenylthioacetamides shows substantial solvent dependency, whereas the corresponding amides do not show solvent dependency of the Z/E isomer ratios. Detailed study of the solvent effects based on molecular dynamics simulations revealed that there are two main modes of hydrogen (H)-bond formation between solvent and (NH)thioacetamide, which influence the Z/E isomer preference of (NH)thioamides. DFT calculations of NH-thioamide in the presence of one or two explicit solvent molecules in the continuum solvent model can effectively mimic the solvation by multiple solvent molecules surrounding the thioamide in MD simulations and shed light on the precise nature of the interactions between thioamide and solvent. Orbital interaction analysis showed that, counterintuitively, the Z/E preference of NH-thioacetamides is mainly determined by steric repulsion, while that of sterically congested N-methylthioacetamides is mainly determined by thioamide conjugation.
- Chan, Erika S.,Hyodo, Tadashi,Ikeda, Hirotaka,Inagaki, Satoshi,Ohwada, Tomohiko,Otani, Yuko,Song, Shuyi,Tang, Yulan,Vu, Kim Anh L.,Yamaguchi, Kentaro
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- Evaluation of dipole moment and electrophilicity on the nature of click-type coupling reaction between thioamide and sulfonyl azide
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A cooperated experimental and computational investigation on sulfonyl amidine formation from thioamides and sulfonyl azides is described. The data support a non-concerted two-step pathway for the coupling reaction and also indicate that dipole moment of t
- Aswad, Muhammad,Chiba, Junya,Tomohiro, Takenori,Hatanaka, Yasumaru
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supporting information
p. 1313 - 1316
(2018/03/26)
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- Enaminones via ruthenium-catalyzed coupling of thioamides and α-diazocarbonyl compounds
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Enaminones can be prepared via the Rh2(OAc)4- catalyzed coupling of α-diazocarbonyl compounds with thioamides. However, rhodium is the most expensive and least abundant among the dominant precious metals used for catalysis. Furthermore, a very limited substrate scope is known for the intermolecular rhodium catalyzed coupling reaction. Therefore, there is a need to find a more economical catalyst substitute with a broad substrate scope. In this paper, we describe the use of Ru(II) catalysts for the synthesis of enaminones. The reaction can be performed efficiently with the Grubbs first-generation catalyst or [(Ph)3P]3RuCl2 in a sealed tube. Both catalysts are much less expensive than Rh 2(OAc)4. Secondary and tertiary thioamides, when reacted with α-diazodiesters, α-diazoketoesters, α-diazodiketones, and α-diazomonoketones give enaminones. Primary thioamides give thiazole derivatives when reacted with α-diazomonoketones. However, with other diazo compounds, primary thioamides also give enaminones. All enaminones are obtained in good yields and with good diastereoselectivity. Accordingly, the method described in this paper is an efficient and economical alternative to the Rh2(OAc)4-catalyzed coupling process.
- Koduri, Naga D.,Wang, Zhiguo,Cannell, Garrett,Cooley, Kate,Lemma, Tsebaot Mesfin,Miao, Kun,Nguyen, Michael,Frohock, Bram,Castaneda, Maria,Scott, Halee,Albinescu, Dragos,Hussaini, Syed R.
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p. 7405 - 7414
(2014/09/17)
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- Lawesson's reagent for direct thionation of hydroxamic acids: Substituent effects on LR reactivity
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To explore the generality and scope of direct thionation of hydroxamic acids (HAs), the reaction of various structurally diverse HAs with Lawesson's reagent was investigated. The yield of thiohydroxamic acid (THAs) is poor when HAs possess bulky acyl and/or N-substituents, acidic α-hydrogen atoms, or an N-phenyl ring. THAs yields were correlated with Brown sigma parameter. The relative rates of two subsequent processes kT2 and kR2 were also measured. Correlation was also found for methine proton chemical shifts of N-isopropyl benzothiohydroxamic acids.
- Przychodzen, Witold
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p. 676 - 684
(2007/10/03)
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