- Efficient Synthesis of N-Sulfonyl β -Arylmethylalaninates from Serine via Ring Opening of N-Sulfonyl Aziridine-2-carboxylate
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We report the efficient synthesis of N-sulfonyl β-arylalanines methyl ester through regioselective ring opening of N-protected aziridines by variety of heteroaryl C-nucleophiles. We have optimized synthesis of N-protected aziridines with versatile protecting groups to afford 4a-c, 6a, and 6b with moderate to good yields using sulfuryl chloride, triethyl amine, and toluene at -50 °C. The present work reports on the studies related to electronic effect of nitrogen substituent on aziridination from the inexpensive starting material DL-serine. The present investigation also reports the efficient synthesis of N-sulfonyl β-arylmethylalaninates (7a-e and 8a-e) by regioselective nucleophilic ring opening of N-sulfonamido-protected aziridines using various aryl moieties such as C-nucleophiles and Lewis acids (InCl3, FeCl3, Cu(OTf)2) as catalysts and some trials by ring opening using Grignard reagent. GRAPHICAL ABSTRACT.
- Chaudhari, Prashant,Bari, Sanjay
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supporting information
p. 401 - 412
(2015/10/29)
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- Efficient regioselective ring opening of activated aziridine-2-carboxylates with [18F]fluoride
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Aziridines can undergo a range of ring-opening reactions with nucleophiles. The regio- and stereochemistry of the products depend on the substituents on the aziridine. Aziridine ring-opening reactions have rarely been used in radiosynthesis. Herein we rep
- Schjoeth-Eskesen, Christina,Hansen, Paul Robert,Kjaer, Andreas,Gillings, Nic
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- Primary amino acid derivatives: Compounds with anticonvulsant and neuropathic pain protection activities
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Pharmacological management remains the primary method to treat epilepsy and neuropathic pain. We have advanced a novel class of anticonvulsants termed functionalized amino acids (FAAs). In this study, we examine FAA derivatives from which the terminal acetyl moiety was removed and termed these compounds primary amino acid derivatives (PAADs). Twenty-seven PAADs were prepared; the central C(2) R-substituent was varied, including C(2) stereochemistry, and the compounds were tested in rodent models of seizures and neuropathic pain. C(2)-Hydrocarbon N-benzylamide PAADs were potent anticonvulsants and excellent anticonvulsant activity (mice, ip; rat, po) was observed for C(2) R-substituted PAADs in which the R group was ethyl, isopropyl, or tert-butyl, and the C(2) stereochemistry conformed to the d-amino acid configuration ((R)-stereoisomer). These values surpassed the activities of several clinical antiepileptic drugs. The C(2) (R)-ethyl and C(2) (R)-isopropyl PAADs also displayed excellent activities in the mouse (ip) formalin neuropathic pain model. Significantly, unlike the FAA structure-activity relationship, PAAD anticonvulsant activity increased upon substitution of a methylene unit for a heteroatom in the R-substituent that was one atom removed from the C(2) site, suggesting that these PAADs function by a different pathway than FAAs.
- King, Amber M.,Salomé, Christophe,Dinsmore, Jason,Salomé-Grosjean, Elise,De Ryck, Marc,Kaminski, Rafal,Valade, Anne,Kohn, Harold
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supporting information; experimental part
p. 4815 - 4830
(2011/10/01)
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- Candida cylindracea Lipase-Catalysed Hydrolysis of Methyl Aziridine-2-carboxylates and 2,3-dicarboxylates
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N-Substituted aziridine-2-carboxylates and 2,3-dicarboxylates have been resolved with good to excellent stereochemical purity by enzymatic hydrolysis catalysed by lipase from Candida cylindracea.
- Bucciarelli, Maria,Forni, Arrigo,Moretti, Irene,Prati, Fabio,Torre, Giovanni
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p. 3041 - 3046
(2007/10/02)
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- SYNTHESIS AND REDUCTION OF DERIVATIVES OF AZIRIDINEMONO- AND -DICARBOXYLIC ACIDS
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Amides and esters of aziridine-2-carboxylic acid were synthesized by the reaction of 1,1,1-trimethyl-2-(2-carboxyethyl)hydrazinium derivatives with an anion-exchange resin or with sodium hydride.Enamines were obtained from 1,1,1-trimethyl-2-hydrazinium salts and basic agents.Methods for the synthesis of amides of aziridine-2,2- and aziridine-2,3-dicarboxylic acids were developed.The stereochemistry of the esters and amides of aziridine-2,3-dicarboxylic acids was established.Dialkylcarbamoylaziridines were reduced with lithium aluminium hydride to 2-(N,N-dialkylaminomethyl)aziridines.The reduction of esters of aziridine-2-carboxylic acid and their functionally substituted derivatives leads to the formation of 2-hydroxymethylaziridines.An O-silylation product was obtained by silylation of 2-hydroxymethylaziridine.
- Trapentsier, P. T.,Kalvin'sh, I. Ya.,Liepin'sh, E. E.,Lukevits, E.
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p. 982 - 989
(2007/10/02)
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