Michio Nakamura, H. Ōkawa, Tasuku Ito
Feb 1, 1987
Citations
0
Influential Citations
10
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
1:3-Cobalt(III) complexes of 3-substituted 1-phenyl-1,3-propanediones (C6H5–CO–CH2–CO–R) have been synthesized, and their stereoselectivities were studied with 400 MHz proton NMR spectroscopy. When the substituent (R) was ethyl, propyl, isopropyl, butyl, or isobutyl, the complexes were obtained in a mixture of fac and mer isomers with the fac/mer ratio of 1/3, demonstrating statistical distribution. When the substituent was t-butoxymethyl or cyclohexyloxymethyl the fac isomer was predominantly formed. The stereoselectivity in the geometrical isomer formation of the complexes was ascribed to the interligand CH/π-interaction occuring between the R group and the phenyl ring. The stereoselectivities of the complexes [Co(l-moba-X)3] (l-moba-X−=4-(l-menthyloxy)-1-(p-X-phenyl)-1,3-butanedionate ion; X=H, Br, CH3) were also examined by means of 1H NMR spectroscopy and compared with the CD spectral result previously reported.