THE SYNTHESIS OF 2 SERIES NOVEL SULFUR-CONTAINING CHIRAL MACROCYCLIC LIGANDS

In this paper, we report that two series of novel optically active sul fur-containing macrocyclic ligands have been synthesized by using L-cy steine as the source of chirality. The synthetic method is in the foll owing: in the presence of NaHCO3, L-cysteine reacts with dibromoalkane to form bridged bis-amino acids under a very mild condition, then, ar e transformed to the bis-esters and cyclized with Lis-acid chlorides t o give the targets 3a-3e. The other series are macrocyclic ligands wit h sulfur-containing pendant. Firstly, L-cysteine reacts with PhCH2Cl t o give beta-benzylthio-L-alanine, and then it is reduced to 2-amino-3- benzylthio-propanol by BH3 . THF. The amino alcohol reacts with bis-to luene-p-sulphonate of diethylene glycol to give the diamine 4f. The sy nthesis of 4g-4h is just like that of 4f. The cyclization of 4f-4h wit h 2,6-pyridinedicarbonyl dichloride gives the macrocyclic ligands 5f-5 h. The structures proposed for these novel macrocycles are consistent with the data obtained from their H-1 NMR, MS and IR spectra and eleme ntal analysis.