Facile synthesis of hydantoins and thiohydantoins in aqueous solution

Baccolini, Graziano; Boga, Carla; Delpivo, Camilla; Micheletti, Gabriele

doi:10.1016/j.tetlet.2011.02.002

Cited by 37 publications

(21 citation statements)

References 44 publications

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“…[26] While the same reaction under excess urea affords 2 a quantitatively (Scheme 1), the analogous reaction with thiourea is nontrivial, leading to a complex mixture of products, including thiohydantoin, [27] urea, 2-thioimidazole, and elemental sulfur. [26] While the same reaction under excess urea affords 2 a quantitatively (Scheme 1), the analogous reaction with thiourea is nontrivial, leading to a complex mixture of products, including thiohydantoin, [27] urea, 2-thioimidazole, and elemental sulfur.…”

Section: Synthesis Of Hetero-glycolurilsmentioning

confidence: 99%

Hetero‐Bambusurils

Reany

Mohite

Keinan

2018

Israel Journal of Chemistry

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Synthetic anion carriers are essential for studying natural ion transporters and channels and for useful applications, such as treatment of channelopathies, supramolecular architecture, anion sensing and catalysis. Driven by the hypothesis that replacement of oxygen atoms in bambusurils (BUs) by other heteroatoms could significantly modify their anion binding properties, we calculated their molecular electrostatic potential and found a general trend of anion‐affinity: S>O>NH. We confirmed these predictions experimentally by synthesizing semithio‐ and semiaza‐BUs and studying their binding and transport properties. Although all analogs are excellent anion binders, only semithio‐bambus[6]uril is an effective transmembrane transporter capable of polarizing lipid membranes through selective anion uniport. Semiaza‐BUs exhibit simultaneous accommodation of three anions, linearly positioned along the main symmetry axis, which is reminiscent of natural chloride channels in E. coli.

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Section: Synthesis Of Hetero-glycolurilsmentioning

confidence: 99%

Hetero‐Bambusurils

Reany

Mohite

Keinan

2018

Israel Journal of Chemistry

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“…The mechanism for the formation of 5-hydroxyhydantoin by photo-oxidation of pyrimidines is unclear, but the most accepted explanation is the formation of dialuric acid or alloxan by hydroxyl radical-addition, followed by loss of carbon. [25] In that case, if the 5-hydroxyhy-dantoin identified in the experiment performed by using deuterated acetylene were originated by the photo-oxidation of pyrimidines, a major proportion of deuterium-free 5-hydroxyhydantoin should be observed. However, the photooxidation of thymine leads to the formation of 5-methyl-5hydroxyhydantoin, [26] indicating that C5 in the hydantoin ring comes from C5 in the pyrimidine ring.…”

Section: Wwwchemeurjorgmentioning

confidence: 99%

A New Route for the Prebiotic Synthesis of Nucleobases and Hydantoins in Water/Ice Solutions Involving the Photochemistry of Acetylene

Menor‐Salván

Marín-Yaseli

2013

Chemistry A European J

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The origin of nucleobases and other heterocycles is a classic question in the chemistry of the origins of life. The construction of laboratory models for the abiotic synthesis of nitrogen heterocycles in plausible natural conditions also aids the understanding and prediction of chemical species in the Solar System. Here, we report a new explanation for the origin of hydantoins, purines, and pyrimidines in eutectic water/ice/urea solutions driven by ultraviolet irradiation (in the 185-254 nm range, UVC) of acetylene under anoxic conditions. An analysis of the products indicates the synthesis of hydantoin and 5-hydroxyhydantoin, the purines uric acid, xanthine, and guanine, and the pyrimidines uracil and cytosine. The synthesis occurred together with the photo-oxidation of bases in a complex process for which possible pathways are proposed. In conclusion, an acetylene-containing atmosphere could contribute to the origin of nucleobases in the presence of a urea/water system by an HCN-independent mechanism. The presence of ice has a dual role as a favorable medium for the synthesis of nucleobases and protection against degradation and as a source of free radicals for the synthesis of highly oxidized heterocycles. A mechanism for the origin of hydantoins and uracil from urea in plausible conditions for prebiotic chemistry is also proposed.

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“…Whereas the condensation reaction of urea with α‐dicarbonyl compounds proceeds quantitatively, the analogous reaction with thiourea is not trivial. For example, the reaction between thiourea and glyoxal in aqueous HCl at 75 °C leads to a complex mixture of products, including 1,4‐diaza‐3,6‐dithiabicyclo[3.3.0]octane‐2,5‐diimine ( 4 ),15,16 thiohydantoin,17 urea, 2‐thioimidazole, and elemental sulfur (Table 1, entry 6). The reported formation of 2 under these conditions was found to be incorrect 18.…”

Section: Resultsmentioning

confidence: 99%

The Synthetic Challenge of Thioglycolurils

et al. 2014

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The very high stability of cucurbiturils under harsh acidic conditions and their reported prolific chemistry over more than three decades pose a question: why has no thiocucurbituril been reported to date? Furthermore, although glycoluril is a highly stable, easily accessible precursor of all cucurbiturils, its sulfur analog represents a yet unmet synthetic challenge. The reaction between glyoxal and thiourea was found to stop at the level of dihydroxyimidazolidine‐2‐thione, which is quite unstable under various acidic conditions. In an attempt to answer these questions, several stable analogs of thioglycoluril, that is, monothioglycoluril, ditolylthioglycoluril, and its diether derivative were prepared and characterized in the hope that they could be employed as building blocks for the synthesis of thiocucurbiturils. Several side products were also obtained that highlight the complex reactivity of thiourea in these reactions. The crystal structures of the above‐mentioned thioglycolurils are dominated by networks of hydrogen‐bonding interactions. Attempts to co‐oligomerize these compounds with formaldehyde clearly suggest that it is impossible to synthesize thiocucurbiturils by the methods commonly used for the preparation of cucurbiturils. Given that thiocucurbiturils are expected to be stable molecules, alternative synthetic strategies that are different from the thermodynamically controlled approaches must be designed.

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Facile synthesis of hydantoins and thiohydantoins in aqueous solution

Cited by 37 publications

References 44 publications

Hetero‐Bambusurils

Hetero‐Bambusurils

A New Route for the Prebiotic Synthesis of Nucleobases and Hydantoins in Water/Ice Solutions Involving the Photochemistry of Acetylene

The Synthetic Challenge of Thioglycolurils

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