- Photocatalytic Intramolecular C-H Amination Using N-Oxyureas as Nitrene Precursors
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Nitrenes are remarkable high-energy chemical species that enable direct C-N bond formation, typically via controlled reactions of metal-stabilized nitrenes. Here, in contrast, the combined use of photocatalysis with careful engineering of the precursor enabled C-H amination forming imidazolidinones and related nitrogen heterocycles from readily accessible hydroxylamine precursors. Preliminary mechanistic results are consistent with the formation of free carbamoyl triplet nitrenes as reactive intermediates.
- Ivanovich, Ryan A.,Polat, Dilan E.,Beauchemin, André M.
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supporting information
p. 6360 - 6364
(2020/09/02)
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- 11,13-MODIFIED SAXITOXINS FOR THE TREATMENT OF PAIN
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Provided herein are compounds, pharmaceutical compositions comprising the compounds, methods of preparing the compounds, and methods of using the compounds and compositions in treating conditions associated with voltage-gated sodium channel function where the compounds are 11,13-modified saxitoxins according to Formula (I): where R4, R4a, R7, R7a, and X2 are as described herein.
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Paragraph 00200; 00269-00270
(2018/10/25)
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- α-Ureidoalkylation of thiosemicarbazide and aminoguanidine
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Optimum conditions for the targeted synthesis of 5,7-dialkyl-3- thioxoperhydroimid-azo[4,5-e][1,2,4]triazin-6-ones, 4,5-bis(3- thiosemicarbazido(guanidinoamino))imidazolidin-2-ones, and 1,3-dialkyl-4- (guanidinoimino)imidazolidin-2-ones by α-ureidoalkylation of thiosemicarbazide or aminoguanidine were found. A novel conglomerate in the series of imidazolidin-2-one derivatives was detected: 4,5-bis(guanidinoamino)- 1,3-dimethylimid-azolidin-2-one dihydrochloride dihydrate. Springer Science+Business Media, Inc. 2006.
- Sigachev,Kravchenko,Belyakov,Lebedev,Makhova
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p. 865 - 872
(2007/10/03)
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- Synthesis of new chiral mono-, di-, tri-, and tetraalkylglycolurils
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Two general procedures were developed for the synthesis of chiral N-mono-, N, N′-di-, N, N′ N″-tri-, and N, N′, N″, N′″-tetraalkylglycolurils based on the reactions of 4,5-dihydroxy-imidazolidin-2-ones or glyoxal with one or two moles of alkylureas, respectively, by acid catalysis. The reactions of N-monoalkyl- and N, N′-dialkylureas with glyoxal proceed regioselectively. The mechanism of these reactions was suggested and partly confirmed by quantum-chemical calculations and experimental data. The enantiomeric separation of some chiral glycolurils by chiral-phase HPLC was carried out for the first time.
- Kravchenko,Sigachev,Maksareva,Gazieva,Trunova,Lozhkin,Pivina,Il'in,Lyssenko,Nelyubina,Davankov,Lebedev,Makhova,Tartakovsky
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p. 691 - 704
(2007/10/03)
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