A chiral molecular cage comprising diethynylallenes and N‐heterotriangulenes for enantioselective recognition

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGChirality, a characteristic tool of molecular recognition in nature, is often a complement of redox active systems. Scientists, in their eagerness to mimic such sophistication, have designed numerous chiral systems based on molecular entities with cavities, such as macrocycles and cages. In an attempt to combine chirality and redox-active species, in this contribution we report the synthesis and detailed characterization of a chiral shape-persistent molecular cage based on the combination of enantiopure diethynylallenes and electron-rich bridged triarylamines, also known as N-heterotriangulenes. Its ability for chiral recognition in solution was revealed through UV/vis titrations with enantiopure helicenes.Agencia Estatal de Investigación | Ref. CTQ2017-85919-RDeutsche Forschungsgemeinschaft | Ref. 182849149Deutsche Forschungsgemeinschaft | Ref. 281029004-SFB1249FP7 People: Marie-Curie Actions | Ref. PIRSES-GA-2012-318930-InTechSEXunta de Galicia | Ref. ED431C 2017/7

Double protonation of a cis-Bipyridoallenophane detected via Chiral-Sensing Switch: the role of Ion Pairs

We prove that the confinement of the conformational space of pyridoallenophanes leads to intense chiroptical responses. Unlike the cyclic dimer [142], single-conformation [141]pyridoallenophanes isomerize under thermal and photochemical conditions. Yet, less-strained [141]-bipyridoallenophanes are stable and are prepared successfully. They, unexpectedly, undergo double protonation as a result of cooperative ion-pairing and hydrogen bonding. The complex formation forces a single configuration of the axis connecting both pyridyl rings recognized by a diagnostic circular dichroism (CD) signal at 330 nm.Agencia Estatal de Investigación | Ref. CTQ2017-84354-PAgencia Estatal de Investigación | Ref. CTQ2017-85919-RXunta de Galicia | Ref. IN607C 2016/03Xunta de Galicia | Ref. ED431C 2017/70Xunta de Galicia | Ref. Ref. ED431G/0