General Protocols for the Preparation of Tröger's Base Analogues and Molecular Recognition by Designed Tröger's Base Receptors

Sammanfattning: 2,8-Dihalo substituted analogues of Tröger’s base were prepared via the Tröger’s base condensation reaction. These compounds were used as synthetic intermediates for the preparation of otherwise inaccessible functionalized Tröger’s base analogues. Based on 2,8-diiodo-4,10-dimethyl-6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine, a mild room temperature protocol for the introduction of terminal functionalized alkynes into the Tröger’s base core via Sonogashira reaction was developed. Efficient double and single bromine-lithium exchanges of 2,8-dibromo-6H,12H-5,11-methanodibenzo[b,f]- [1,5]diazocine afforded C2-symmetric and asymmetric analogues respectively. The desymmetrization procedure allowed for the sequential introduction of two different electrophiles. Using the 2,8-dihalo substituted analogues of Tröger’s base as aryl halides, as well as precursors of organometallic species, allowed for the synthesis of novel analogues via cross-coupling reactions. Association constants of terminal bisammonium salts with a bis(crown-ether) Tröger’s base receptor were increased by exploiting solvophobic interactions with the Tröger’s base in it’s cavity, and CH-Pi and Pi-Pi -interactions with the benzo groups.