Naslov
A Two-step Asymmetric Synthesis of Disubstituted N-Tosyl Aziridines Having 98 to 100% ee : Use of a Phosphazene Base

Autori
Solladié-Cavallo, A. ; Roje, Marin ; Welter, R. ; Šunjic, Vitomir

Izvornik
Journal of organic chemistry (0022-3263) 69 (2004), 4; 1409-1412

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Enantioselective aziridination; Alkene aziridination; Sulfur ylides; Imines; Catalysts; Epoxides; Derivatives; Oxathiane; Additions; Ligands

Sažetak
Unknown diaryl (1-3) and alkyl-phenyl (4, 5) N-tosyl aziridines have been successfully synthesized from pure (R, R, R, Ss)-(-)-sulfonium salt derived from Eliel's oxathiane, tosylimines 11a-f, and using a phosphazene base (EtP2) to generate the ylide. Both cis and trans aziridines have exceptionally high enantiomeric purities (98.7-99.9%). The (2R, 3R)-configuration of trans-3 and the (2R, 3S)-configuration of cis-4 have been determined by X-ray analysis using the Bijvoet method. The R-configuration found at C2 is consistent with the model and all previous results, therefore all trans-aziridines and cis-aziridines have been assigned the (2R, 3R)- and the (2R, 3S)-configurations, respectively. This two-step asymmetric synthesis can be easily used on gram quantities and involves no unstable/hazardous reagent. The chiral auxiliary is used in a stoichiometric amount but is recovered in high yield and reused.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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