- Synthesis of the 1-Bromotricyclo[4.1.0.02,7]heptane Adduct with 2-Bromoethanesulfonyl Bromide and Its Transformations
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Abstract: The addition of 2-bromoethanesulfonyl bromide to1-bromotricyclo[4.1.0.02,7]heptane at theC1–C7 centralbicyclobutane bond follows a radical mechanism to give 1:1 adduct with abicyclo[3.1.1]heptane structure. Treatment of the adduct with triethylamineleads to the formation of vinyl sulfone as a result of 1,2-dehydrobromination,and its reaction with 2 equiv of sodium methoxide involves 1,2- and1,3-dehydrobromination to afford7-bromo-1-(ethenesulfonyl)tricyclo[4.1.0.02,7]heptane.The latter is capable of reacting with sodium methoxide and sodiummethanesulfonate to form nucleophilic addition products.
- Kostryukov, S. G.,Masterova, Yu. Yu.
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- Reactions of Tricyclo[4.1.0.02,7]heptane and 1-Methyltricyclo[4.1.0.02,7]heptane with 2-Bromoethanesulfonyl Bromide
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Abstract: 2-Bromoethanesulfonyl bromide reacts with tricyclo[4.1.0.02,7]heptane and 1-methyltricyclo[4.1.0.02,7]heptane according to a radical mechanism to give products of both anti and syn addition across the C1–C7 central bicyclobutane bond having a norpinane (bicyclo[3.1.1]heptane) structure. Treatment of the adducts with triethylamine leads to the formation of vinyl sulfones as a result of 1,2-dehydrobromination, and their reaction with sodium methoxide involves 1,2- and 1,3-dehydrobromination and nucleophilic addition, depending on the substrate structure and reactant ratio.
- Kostryukov, S. G.,Masterova, Yu. Yu.
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- Naphthocyanines for Use as Contrast Agents
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Cyanine dyes having optional sulfonic acid substituents on the aromatic nucleus have been developed for use as contrast agents for assisting in surgery and diagnosis, especially for simplifying the surgical removal of basal membranes of the eye, such as the internal limiting membrane (ILM), and for dyeing the lens capsule.
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Paragraph 0093
(2013/06/04)
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- Cyanine dyes as optical contrast agents for ophthalmological surgery
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Cyanine dyes were prepared as optical contrast media for supporting the surgery of the lamina limitans interna (LLI) of the retina and other structures of the human eye. Their absorption spectra were adapted both to the spectral sensitivity of the human eye and to standard illumination. The contrast could be further amplified by the application of the strong fluorescence of the dyes used. The binding of the dyes to various surfaces was studied. No toxic effects could be detected for the applied dyes.
- Langhals, Heinz,Varja, Ana,Laubichler, Peter,Kernt, Marcus,Eibl, Kirsten,Haritoglou, Christos
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experimental part
p. 3903 - 3925
(2011/07/31)
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- Synthesis and use of sulfonamide-, sulfoxide-, or sulfone-containing aminoglycoside-CoA bisubstrates as mechanistic probes for aminoglycoside N-6′-acetyltransferase
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Aminoglycoside-coenzyme A conjugates are challenging synthetic targets because of the wealth of functional groups and high polarity of the starting materials. We previously reported a one-pot synthesis of amide-linked aminoglycoside-CoA bisubstrates. These molecules are nanomolar inhibitors of aminoglycoside N-6′-acetyltransferase Ii (AAC(6′)-Ii), an important enzyme involved in bacterial resistance to aminoglycoside antibiotics. We report here the synthesis and biological activity of five new aminoglycoside-CoA bisubstrates containing sulfonamide, sulfoxide, or sulfone groups. Interestingly, the sulfonamide-linked bisubstrate, which was expected to best mimic the tetrahedral intermediate, does not show improved inhibition when compared with amide-linked bisubstrates. On the other hand, most of the sulfone- and sulfoxide-containing bisubstrates prepared are nanomolar inhibitors of AAC(6′)-Ii.
- Gao, Feng,Yan, Xuxu,Zahr, Omar,Larsen, Aaron,Vong, Kenward,Auclair, Karine
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supporting information; experimental part
p. 5518 - 5522
(2009/05/30)
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- Process for synthesizing disulfides
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This invention relates to a process for producing a substantially pure disulfide compound of Formula II as disclosed herein, such as disodium 2,2′-dithiobis ethane sulfonate, by an efficient procedure from available, relatively inexpensive raw materials.
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Page/Page column 4
(2008/06/13)
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- The mechanism of hydrolysis of 2-hydroxyethanesulfonyl chloride: the intermediacy of 1,2-oxathietane 2,2-dioxide (β-sultone)
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The hydrolysis of 2-hydroxyethanesulfonyl chloride (1) has been investigated with the aid of kinetic and product analysis studies.The results are quantitatively consistent with the mechanism of hydrolysis shown in Scheme 1, the chief features of which are (a) formation of β-sultone (2) and its rapid further reaction (the major pathway), together with (b) a minor direct hydrolysis route.The kinetics of both the β-sultone formation and the direct hydrolysis shows two terms, one first order in 1 alone, and the other first order in hydroxide as well; the rates of the first- and second-order reactions are lowered by added sodium chloride.It is suggested (a) that the unimolecular β-sultone formation involves 1 in a complex with water (as in 9) and that the water acts as a general base in the cyclization to 2, and (b) the hydroxide-promoted reaction proceeds by cyclization of the conjugate base of 1 (i.e., 10).The unimolecular direct hydrolysis is regarded as a conventional hydrolysis of a sulfonyl chloride with attack of the water with general base assistence from a second water molecule.The hydroxide-promoted direct reaction in D2O leads to no uptake of deuterium, showing taht the reaction does not go by way of the sulfene, and a reaction by way of a six-membered cyclic transition state is tentatively proposed.Evidence is presented that the chloride ion rate suppression is not primarily due to reaction of β-sultone with Cl- to give back 1; the possible origins of the effect are discussed.Key words: sulfonyl chloride, 2-hydroxyethanesulfonyl chloride, β-sultone, kinetics of sulfonyl chloride hydrolysis, mechanism of sulfonyl chloride hydrolysis
- King, James Frederick,Khemani, Kishan Chand
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p. 2162 - 2172
(2007/10/02)
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