A short synthesis of each enantiomer of 2,3-diaminopropyl hydrogensulfate is described starting from (2R)- and (2S)-asparagine. The compounds serve as inhibitors for pyridoxal 5'-phosphate-dependent (2S)-glutamate l-semialdehyde aminotransferase, a target for selective herbicides and antibacterial agents on the tetrapyrrole biosynthetic pathway. The (2R)-enantiomer, as predicted, serves as a potent irreversible inactivator. (C) 2000 Elsevier Science Ltd. All rights reserved.
Synthesis of Metal–(Pentadentate-Salen) Complexes: Asymmetric Epoxidation with Aqueous Hydrogen Peroxide and Asymmetric Cyclopropanation (salenH2:N,N′-bis(salicylidene)ethylene-1,2-diamine)
作者:Hiroaki Shitama、Tsutomu Katsuki
DOI:10.1002/chem.200601420
日期:2007.6.4
manganese(III) and cobalt(II) complexes, in which the fifth ligand is expected to intramolecularly coordinate to the metal center and exert a trans effect. Indeed, high enantioselectivity has been achieved in epoxidations using aqueous hydrogen peroxide as the terminal oxidant and in cyclopropanations with these complexes as catalysts. In general, metallosalen-catalyzed reactions have been carried out
Halogeno, sulfato, and nitrato Pt (II) complexes of 2, 3-diaminopropanol (pnOH) isomers were synthesized and their antitumor activities against leukemia L1210 were tested. The conformations of their chelate rings were determined to be λ-and δ-gauche forms for R- and S-pnOH, respectively, by 13C-nuclear magnetic resonance and circular dichroism spectral analyses. Among the pnOH isomers, Pt (II) complexes containing R-pnOH showed higher antitumor activity than those containing S- or racemic pnOH. It seems that there may be a relationship between the conformations of the chelate rings and antitumor activity in the case of five-membered chelate rings.