Controlling Helix Sense at N- and C-Termini in Quinoline Oligoamide Foldamers by β-Pinene-Derived Pyridyl Moieties
作者:Lu Zheng、Yulin Zhan、Chengyuan Yu、Fu Huang、Ying Wang、Hua Jiang
DOI:10.1021/acs.orglett.7b00510
日期:2017.3.17
A series of quinoline oligoamide foldamers bearing a beta-pinene-derived pyridyl group at the N-terminus or the C terminus were synthesized, and the efficiencies of chiral inductions have been evaluated by H-1 NMR and CD spectra. The chiral inductions were quantitative when chiral pyridyl acid was appended at the N-terminus, but were inferior when chiral pyridyl amine was appended at the C-terminus. Unexpectedly, N-oxidation on the pyridine ring at the C-terminus does not notably enhance the chiral induction efficiency in spite of the presence of three-center hydrogen bonds.