Dynamic molecular propeller: supramolecular chirality sensing by enhanced chiroptical response through the transmission of point chirality to mobile helicity

The secondary terephthalamide host 1a-H attached to four aryl blades is prepared from tetrabromide by Suzuki-Miyaura coupling and has undergone a conformational change from a nonpropeller anti-form to a propeller-shaped syn-form upon complexation with ditopic guests such as p-xylylenediammonium derivatives (R,R)/(S,S)-3. The chirality generation-chirality biasing protocol is applied to a neurotransmitter, (-)-phenylephrine, which has acted as a chiral ditopic guest.