Chiral recognition of α-amino acids by an optically active (2S,5S,8S,11S)-2,5,8,11-tetraethyl cyclen cobalt(III) complex.
The optically active cobalt(III) complex with chiral cyclen, (2S,5S,8S,11S)-2,5,8,11-tetraethyl-1,4,7,10-tetraazacyclododecane, preferentially binds to D-phenylglycine (D-Phg) or D-t-leucine (D-t-Leu) rather than L-Phg or L-t-Leu, respectively, with 20% de in dimethyl sulfoxide at 293 K. Comparative studies on the crystal structures of cobalt(III) complexes with d-Phg and l-Phg revealed that the diastereoselectivity is due to the difference in the steric hindrance that should occur between the amino group of Phg and the ethyl group of cyclen.
Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Shohei
S
Tashiro
Yasuyo
Y
Ogura
Sei
S
Tsuboyama
Kaoru
K
Tsuboyama
Mitsuhiko
M
Shionoya
D003035:Cobalt / Q000737:chemistry; D056831:Coordination Complexes / Q000737:chemistry; D018360:Crystallography, X-Ray; D005998:Glycine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D006571:Heterocyclic Compounds / Q000737:chemistry*; D007930:Leucine / Q000737:chemistry / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D013237:Stereoisomerism
D056831:Coordination Complexes; D006571:Heterocyclic Compounds; D003035:Cobalt; C008852:2-phenylglycine; D007930:Leucine; D005998:Glycine