Light- and Temperature-Controlled Hybridization, Chiral Induction and Handedness of Helical Foldamers

Abstract

Helical foldamers have attracted much attention over the last decades given their resemblance to certain biomacromolecules and their potential in domains as different as pharmaceutics, catalysis and photonics. Various research groups have successfully controlled the right- or left- handedness of these oligomers by introducing stereogenic centers through covalent or non-covalent chemistry. However, developing helical structures whose handedness can be reversibly switched remains a major challenge for chemists. To date, such an achievement has been reported with light-responsive single-stranded foldamers only. Herein, we demonstrate that grafting a unidirectional motor onto foldamer strands constitutes a relevant strategy to i) control the single or double helical state of a foldamer, ii) switch on the chiral induction process from the motor to the helical strands and iii) select the handedness of double helical structures through photochemical and thermal stimulations.