- N-Boc-O-tosyl hydroxylamine as a safe and efficient nitrogen source for the N-amination of aryl and alkyl amines: Electrophylic amination
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β-Boc-protected aryl and alkyl hydrazines, useful intermediates for azapeptides and N-substituted pyrazoles, were synthesized by electrophylic amination methodology, using less energetic N-Boc-O-tosyl hydroxylamine as an efficient nitrogen source. Also we have demonstrated a two-step, chromatography-free synthesis of N-Boc-O-tosyl hydroxylamine. Georg Thieme Verlag Stuttgart - New York.
- Baburaj, Thankappan,Thambidurai, Sivalingam
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p. 1993 - 1996
(2011/10/08)
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- N-Boc-3-trichloromethyloxaziridine: A new, powerful reagent for electrophilic amination
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The aza-Wittig reaction of Ph3P=N-Boc with chloral, followed by the oxone oxidation of the resulting imine, afforded N-Boc-3- trichloromethyloxaziridine in excellent yield. This new oxaziridine proved to be a powerful electrophilic amination reagent.
- Vidal, Joelle,Hannachi, Jean-Christophe,Hourdin, Gwenaelle,Mulatier, Jean-Christophe,Collet, Andre
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p. 8845 - 8848
(2007/10/03)
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- N-alkyloxycarbonyl-3-aryloxaziridines: Their preparation, structure, and utilization as electrophilic amination reagents
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This paper reports the synthesis of a series of N-protected oxaziridines (N-Moc, Boc, Z or Fmoc) and discusses their ability to deliver their N-alkoxycarbonyl fragment to amines, enolates, sulfur, and phosphorus nucleophiles (electrophilic amination). These oxaziridines are prepared by oxidation of the corresponding imines with oxone or anhydrous MCPBA lithium salt as the source of oxygen. They transfer their N-protected fragment to primary and secondary amines to give protected hydrazines in fair to excelent yield. The nitrogen transfer to free amino acids (in form of their R4N+ salts) is particularly fast, even at low temperature, providing L (or D) N-protected α-hydrazino acids. Enolates are C-aminated to give N-protected α-amino ketones, esters, or amides in modest yield, due to a side aldol reaction of the unreacted enolate with the released benzaldehyde. With tertiary amines (Et3N), sulfides (PhSMe), and phosphines (Ph3P), amination and oxidation proceed in a parallel way; the amount of amination product increases when the temperature is lowered (kinetic control). Some of the factors that can orient the oxaziridine reactivity towards amination or oxidation of nucleophiles are considered.
- Vidal, Joelle,Damestoy, Stephanie,Guy, Laure,Hannachi, Jean-Christophe,Aubry, Andre,Collet, Andre
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p. 1691 - 1709
(2007/10/03)
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- Electrophilic Amination Reagents: A New Method For The Preparation Of 3-Aryl-N-BOC (or N-FMOC) Oxaziridines
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N-BOC or N-FMOC benzaldimines are oxidized to the corresponding 3-Aryl-N-BOC or N-FMOC oxaziridines by reaction with Li m-chloroperoxybenzoate under aprotic conditions.The new oxaziridines can transfer their N-BOC or N-FMOC group to morpholine to give the corresponding Nβ-protected hydrazines.
- Vidal, Joelle,Damestoy, Stephanie,Collet, Andre
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p. 1439 - 1442
(2007/10/02)
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- Electrophilic Amination: Preparation and Use of N-Boc-3-(4-cyanophenyl)oxaziridine, a New Reagent That Transfers a N-Boc Group to N- and C-Nucleophiles
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We describe the preparation of the title compound 2b via aza-Wittig reaction of N-Boc-triphenyliminophosphorane (6) with 4-cyanobenzaldehyde followed by Oxone oxidation of the resulting imine 5b.Oxaziridine 2b is a stable, crystalline solid, which transfers under mild conditions its N-Boc fragment to primary and secondary amines (to give Nβ-Boc-hydrazines) and enolates (to give N-Boc-amino drivatives).
- Vidal, Joelle,Guy, Laure,Sterin, Sebastien,Collet, Andre
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p. 4791 - 4793
(2007/10/02)
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