Catalytic enantioselective desymmetrization of meso-N-acylaziridines with TMSCN.
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.
Mita
Tsuyoshi
T
Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan.
Fujimori
Ikuo
I
Wada
Reiko
R
Wen
Jianfeng
J
Kanai
Motomu
M
Shibasaki
Masakatsu
M
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*
D000598:Amino Acids, Cyclic; D001388:Aziridines; D003486:Cyanides; D014297:Trimethylsilyl Compounds; C058010:trimethylsilyl cyanide