Synthesis of novel chiral tetra-(hydrazinecarboxamide) cyclophane macrocycles

A novel class of chiral enantiomerically pure C2-symmetric polyamide macrocycles has been synthesized from the reaction of chiral dioxolane dicarbohydrazides, obtained from commercially available tartaric acid, and aromatic diisocyanates. The novel macrocycles form in almost quantitative yields in a chemoselective [2+2]-cyclocondensation reaction under conformational bias of the dicarbohydrazides. The reaction takes place in anhydrous THF at a relatively high concentration of reactants without addition of external templates or application of high dilution conditions. The structures of the novel polyamide macrocycles were verified and fully assigned by 1H NMR, 13C NMR, 2D ROESY NMR, 2D HMBC, 2D HMQC, DEPT 135, FT IR, and CD spectroscopy.