title: Catalytic enantioselective desymmetrization of meso-N-acylaziridines with TMSCN.
abstract: A catalytic enantioselective desymmetrization of meso-N-p-nitrobenzoylaziridines with TMSCN was developed using a chiral gadolinium catalyst generated from Gd(OiPr)3 and d-glucose-derived ligand 1. In this reaction, the addition of a catalytic amount of trifluoroacetic acid (TFA) improved enantioselectivity. High enantioselectivity was obtained from a range of meso-aziridines at 0-60 degrees C. The product could be easily transformed into beta-amino acids. Thus, the developed catalytic enantioselective desymmetrization reaction allowed for efficient catalytic synthesis of chiral cyclic beta-amino acids. The incorporation of TFA into the catalyst complex was observed using ESI-MS. Generation of this new complex might be the origin of the improved enantioselectivity.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Mita
authors.forename: Ikuo
authors.initials: I
authors.lastname: Fujimori
authors.forename: Reiko
authors.initials: R
authors.lastname: Wada
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Wen
authors.forename: Motomu
authors.initials: M
authors.lastname: Kanai
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Shibasaki
mesh_terms: D000598:Amino Acids, Cyclic / Q000138:chemical synthesis* / Q000737:chemistry; D001388:Aziridines / Q000737:chemistry*; D002384:Catalysis; D003486:Cyanides / Q000737:chemistry*; D007536:Isomerism; D014297:Trimethylsilyl Compounds / Q000737:chemistry*
chemical_list: D000598:Amino Acids, Cyclic; D001388:Aziridines; D003486:Cyanides; D014297:Trimethylsilyl Compounds; C058010:trimethylsilyl cyanide