Pincer Ligands Based on alpha-Amino Acids: I. Synthesis of Polydentate Ligands from Pyrrole-2,5-dicarbaldehyde

摘要

New chiral pincer ligands having CH=N moieties were synthesized by condensation of lH-pyrrole-2,5-dicarbaldehyde with L-methionine and L-histidine methyl esters. Their reduction under mild conditions (NaBH4, -30°C) gave the corresponding amine ligands in high yields. An improved procedure for the preparation of lH-pyrrole-2,5-dicarbaldehyde was proposed