The conversions of isothiazolium salts into thiophenecarboxylic ester derivatives

1984 ◽  
Vol 62 (8) ◽  
pp. 1580-1584 ◽  
Author(s):  
David M. McKinnon ◽  
K. Ann Duncan ◽  
Lesley M. Millar

Several 3-aminothiophene-2-carboxylic ester derivatives are made by reaction of potassium 3-ethoxy-3-oxopropanoate with isothiazolium salts or by reaction with 2-ethoxy-2-oxoethylidenedimethylsulfurane. In the latter case deaminated products are also isolated. These products are consistent with initial nucleophilic attack on the sulfur atom of the isothiazolium salt. In one case a pyrrole derivative is formed by a novel rearrangement of an intermediate aziridine derivative. Some further derivatives of 3-benzylaminobenzo[b]thiophene are described.

1973 ◽  
Vol 51 (18) ◽  
pp. 3081-3086 ◽  
Author(s):  
David M. Mckinnon ◽  
Mohamed E. Hassan

A variety of isothiazolium salts has been prepared and allowed to react with sodium benzoylacetate. 2-Benzoylthiophenes are obtained, suggesting that the position of initial nucleophilic attack is at the sulfur atom of the heterocyclic cation. Reaction with hydrogen sulfide gave acyclic reduction products, or 1,2-dithiole derivatives, depending on the type of substituent on nitrogen in the isothiazolium salts.


2021 ◽  
Author(s):  
Min Shi ◽  
Hao-Zhao Wei ◽  
Yin Wei

An unprecedented reaction pattern of functionalized methylenecyclopropanes (MCPs) has been disclosed in this paper, in which the nucleophilic attack of anionic species onto partially polarity-reversed MCP unit can be realized...


Author(s):  
Elena Chirkina ◽  
Leonid Krivdin ◽  
Nikolay Korchevin

The theoretical mechanism of the interaction of 1,3-dichloropropene with 1,2- ethanedithiol in the system "hydrazine hydrate-KOH" has been proposed by the method of B3LYP / 6- 311 ++ G (d, p) in the framework of the theory of the electron-density functional according to which the reaction proceeds successively in several stages, including the nucleophilic substitution of the chlorine atom present in the sp3-hybridized carbon atom with a sulfur atom to form a mono-substitution product that undergoes a prototropic allylic rearrangement that migrates the double bond to the sulfur atom, followed by closure in the dithiolane cycle due to the nucleophilic attack of the sulfide anion of the second thiol group of the reagent per carbon atom located in the γ-position with respect to the second chlorine atom.


Author(s):  
Elena Chirkina ◽  
Leonid Krivdin ◽  
Nikolay Korchevin

The theoretical mechanism of the interaction of 1,3-dichloropropene with 1,2-ethanedithiol in the system "hydrazine hydrate-KOH" has been proposed by the method of B3LYP / 6-311 ++ G (d, p) in the framework of the theory of the electron-density functional according to which the reaction proceeds successively in several stages, including the nucleophilic substitution of the chlorine atom present in the sp3-hybridized carbon atom with a sulfur atom to form a mono-substitution product that undergoes a prototropic allylic rearrangement that migrates the double bond to the sulfur atom, followed by closure in the dithiolane cycle due to the nucleophilic attack of the sulfide anion of the second thiol group of the reagent per carbon atom located in the γ-position with respect to the second chlorine atom.


1977 ◽  
Vol 55 (7) ◽  
pp. 1123-1128 ◽  
Author(s):  
David M. McKinnon ◽  
Mohammed E. R. Hassan ◽  
Mohinder Chauhan

Isothiazolium salts react with a number of carbanions by attack on sulfur. Thiophene derivatives, formed by ring opening and recyclization, are often products but with cyclopentadiene, pseudoazulene products are obtained. 3-Amino-2-acylthiophenes, prepared by suitable nucleophilic attack, are synthetic precursors of thieno[2,3-c]isothiazolium salts


2003 ◽  
Vol 5 (21) ◽  
pp. 3791-3794 ◽  
Author(s):  
Susana Mantecón ◽  
Juan J. Vaquero ◽  
Julio Alvarez-Builla ◽  
María Luz de la Puente ◽  
Juan F. Espinosa ◽  
...  

1996 ◽  
Vol 30 (3) ◽  
pp. 194-196 ◽  
Author(s):  
N. I. Romanenko ◽  
I. V. Fedulova ◽  
B. A. Priimenko ◽  
N. A. Klyuev ◽  
T. A. Pereverzeva ◽  
...  

Azoles are one of a cyclic  derivatives  of chemical  heterocyclic chemical and organic compounds including g a five member di unsaturated ring structure composed of  bi  nitrogen atoms at position (3 and 4) and one sulfur atom at position (1).


mBio ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Liqiong Liu ◽  
Susu Jiang ◽  
Mai Xing ◽  
Chao Chen ◽  
Chongde Lai ◽  
...  

ABSTRACT DNA phosphorothioate (PT) modification, in which the nonbridging oxygen in the sugar-phosphate backbone is substituted by sulfur, is catalyzed by DndABCDE or SspABCD in a double-stranded or single-stranded manner, respectively. In Dnd and Ssp systems, mobilization of sulfur in PT formation starts with the activation of the sulfur atom of cysteine catalyzed by the DndA and SspA cysteine desulfurases, respectively. Despite playing the same biochemical role, SspA cannot be functionally replaced by DndA, indicating its unique physiological properties. In this study, we solved the crystal structure of Vibrio cyclitrophicus SspA in complex with its natural substrate, cysteine, and cofactor, pyridoxal phosphate (PLP), at a resolution of 1.80 Å. Our solved structure revealed the molecular mechanism that SspA employs to recognize its cysteine substrate and PLP cofactor, suggesting a common binding mode shared by cysteine desulfurases. In addition, although the distance between the catalytic Cys314 and the substrate cysteine is 8.9 Å, which is too far for direct interaction, our structural modeling and biochemical analysis revealed a conformational change in the active site region toward the cysteine substrate to move them close to each other to facilitate the nucleophilic attack. Finally, the pulldown analysis showed that SspA could form a complex with SspD, an ATP pyrophosphatase, suggesting that SspD might potentially accept the activated sulfur atom directly from SspA, providing further insights into the biochemical pathway of Ssp-mediated PT modification. IMPORTANCE Apart from its roles in Fe-S cluster assembly, tRNA thiolation, and sulfur-containing cofactor biosynthesis, cysteine desulfurase serves as a sulfur donor in the DNA PT modification, in which a sulfur atom substitutes a nonbridging oxygen in the DNA phosphodiester backbone. The initial sulfur mobilization from l-cysteine is catalyzed by the SspA cysteine desulfurase in the SspABCD-mediated DNA PT modification system. By determining the crystal structure of SspA, the study presents the molecular mechanism that SspA employs to recognize its cysteine substrate and PLP cofactor. To overcome the long distance (8.9 Å) between the catalytic Cys314 and the cysteine substrate, a conformational change occurs to bring Cys314 to the vicinity of the substrate, allowing for nucleophilic attack.


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