219738-95-1Relevant articles and documents
Expedite protocol for construction of chiral regioselectively N-protected monosubstituted piperazine, 1,4-diazepane, and 1,4-diazocane building blocks
Crestey, Francois,Witt, Matthias,Jaroszewski, Jerzy W.,Franzyk, Henrik
scheme or table, p. 5652 - 5655 (2009/12/08)
(Chemical Equation Presented) This paper describes the first study of solution-phase synthesis of chiral monosubstituted piperazine building blocks from nosylamide-activated aziridines. The protocol, involving aminolysis of the starting aziridines with ω-amino alcohols and subsequent Fukuyama-Mitsunobu cyclization, offers the advantage of mild conditions as well as short reaction times, and it leads to optically pure N-Boc- or N-Ns-protected piperazines. This four-step sequence, requiring only a single final chromatographic purification, was extended to include novel diazepane and diazocane derivatives.
β3-Amino acids by nucleophilic ring-opening of N-nosyl aziridines
Farràs, Jaume,Ginesta, Xavier,Sutton, Peter W,Taltavull, Joan,Egeler, Frank,Romea, Pedro,Urpí, Fèlix,Vilarrasa, Jaume
, p. 7665 - 7674 (2007/10/03)
N-Nosyl aziridines can be easily prepared from 1,2-amino alcohols derived from α-amino acids. Nucleophilic ring-opening of N-nosyl aziridines with cyanide ions followed by hydrolysis of the corresponding nitriles lead to N-nosyl β3-amino acids, which can be readily converted into a variety of derivatives bearing adequate functionality for peptide synthesis. The proposed methodology is simple, efficient, and amenable to large-scale preparations.
Deprotection of sulfonyl aziridines
Alonso, Diego A.,Andersson, Pher G.
, p. 9455 - 9461 (2007/10/03)
The deprotection of the chiral N-sulfonyl aziridines 1-3 has been studied under different desulfonylation conditions. Two methods for the efficient aleprotection of 2-benzyl-, 2-phenyl-, and 2-carboxyl-N- sulfonylaziridines were found. The desulfonylation with lithium and a catalytic amount of di-tert-butyl biphenyl in THF at -78 °C led to the corresponding NH aziridines with yields up to 85%. Alternatively, the desulfonylation could be carried out with magnesium in methanol under ultrasonic conditions. The latter proved to be a very mild method and afforded the desulfonylated aziridines with yields up to 75%, even when the 2-phenyl substituted aziridine 2 was the studied substrate. Furthermore, in all the cases studied, no racemization was observed in the chiral center of the aziridines.