| 1. |
- Chinthakindi, Praveen Kumar, et al.
(författare)
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Sulfonimidamides in Medicinal and Agricultural Chemistry
- 2017
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851. ; 56:15, s. 4100-4109
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis and evaluation of structural analogues and isosteres are of central importance in medicinal and agricultural chemistry. The sulfonamide functional group represents one of the most important amide isosteres in contemporary drug design, and about 500 such compounds have overcome both the pharmacological and regulatory hurdles that precede studies in humans. The mono aza analogues of sulfonamides, that is, sulfonimidamides, are rapidly gaining popularity as a novel functional group among synthetic chemists involved in the design of biologically active compounds for both pharmaceutical and agrochemical applications. Herein, we review these recent developments to showcase the promise of this functional group.
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| 2. |
- Dong, Hai, et al.
(författare)
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Control of the ambident reactivity of the nitrite ion
- 2013
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Ingår i: Organic and biomolecular chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 11:4, s. 648-653
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Tidskriftsartikel (refereegranskat)abstract
- In previous studies, it was reported that a neighbouring equatorial ester group is essential for a good yield of nitrite-mediated triflate inversion, whereas with neighbouring benzyl ether groups or axial ester groups, mixtures are generally produced. In the present study, the origin of this difference was addressed. The ambident reactivity of the nitrite ion has been found to be the cause of the complex product formation observed, which can be controlled by a neighbouring equatorial ester group. Both N-attack and O-attack occur in the absence of the ester group, whereas O-attack is favoured in its presence. A neighbouring group assistance mechanism is proposed, in addition to steric effects, based on secondary interactions between the neighbouring ester group and the incoming nucleophile. High-level quantum mechanical calculations were carried out in order to delineate this effect. The theoretical results are in excellent agreement with experiments, and suggest a catalytic role for the neighbouring equatorial ester group.
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| 3. |
- Dong, Hai, et al.
(författare)
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Control of the ambident reactivity of the nitrite ion.
- 2013
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Ingår i: Organic and Biomolecular Chemistry. - 1477-0539 .- 1477-0520. ; 11:4, s. 648-653
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Tidskriftsartikel (refereegranskat)abstract
- In previous studies, it was reported that a neighboring equatorial ester group is essential for a good yield of nitrite-mediated triflate inversion, whereas with neighboring benzyl ether groups or axial ester groups, mixts. are generally produced. The origin of this difference was addressed. The ambident reactivity of the nitrite ion is the cause of the complex product formation obsd., which can be controlled by a neighboring equatorial ester group. Both N-attack and O-attack occur in the absence of the ester group, whereas O-attack is favored in its presence. A neighboring group assistance mechanism is proposed, in addn. to steric effects, based on secondary interactions between the neighboring ester group and the incoming nucleophile. High-level quantum mech. calcns. were carried out to delineate this effect. The theor. results are in excellent agreement with expts., and suggest a catalytic role for the neighboring equatorial ester group. [on SciFinder(R)]
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| 4. |
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| 5. |
- Norberg, Oscar, et al.
(författare)
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Synthesis and binding affinity analysis of alpha 1-2-and alpha 1-6-O/S-linked dimannosides for the elucidation of sulfur in glycosidic bonds using quartz crystal microbalance sensors
- 2017
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Ingår i: Carbohydrate Research. - : ELSEVIER SCI LTD. - 0008-6215 .- 1873-426X. ; 452, s. 35-42
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Forskningsöversikt (refereegranskat)abstract
- The role of sulfur in glycosidic bonds has been evaluated using quartz crystal microbalance methodology. Synthetic routes towards alpha 1-2- and alpha 1-6-linked dimannosides with S-or O-glycosidic bonds have been developed, and the recognition properties assessed in competition binding assays with the cognate lectin concanavalin A. Mannose-presenting QCM sensors were produced using photoinitiated, nitrenemediated immobilization methods, and the subsequent binding study was performed in an automated flow-through instrumentation, and correlated with data from isothermal titration calorimetry. The recorded Kd-values corresponded well with reported binding affinities for the O-linked dimannosides with affinities for the alpha 1-2-linked dimannosides in the lower micromolar range. The S-linked analogs showed slightly disparate effects, where the alpha 1-6-linked analog showed weaker affinity than the O-linked dimannoside, as well as positive apparent cooperativity, whereas the alpha 1-2-analog displayed very similar binding compared to the O-linked structure.
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