AUTHOR=Liu Chunhong , Yu Zhipeng , Yao Jiabin , Ji Jiecheng , Zhao Ting , Wu Wanhua , Yang Cheng 

TITLE=Solvent-Driven Chirality Switching of a Pillar[4]arene[1]quinone Having a Chiral Amine-Substituted Quinone Subunit

JOURNAL=Frontiers in Chemistry

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.713305

DOI=10.3389/fchem.2021.713305

ISSN=2296-2646

ABSTRACT=<p>Several new chiral pillar[4]arene[1]quinone derivatives were synthesized by reacting pillar[4]arene[1]quinone (<bold>EtP4Q1</bold>), containing four 1,4-diethoxybenzene units and one benzoquinone unit, with various chiral amines <italic>via</italic> Michael addition. Due to the direct introduction of chiral substituents on the rim of pillar[n]arene and the close location of the chiral center to the rim of <bold>EtP4Q1</bold>, the newly prepared compounds showed unique chiroptical properties without complicated chiral resolution processes, and unprecedented high anisotropy factor of up to −0.018 at the charge transfer absorption band was observed. Intriguingly, the benzene sidearm attached pillar[4]arene[1]quinone derivative <bold>1a</bold> showed solvent- and complexation-driven chirality inversion. This work provides a promising potential for absolute asymmetric synthesis of pillararene-based derivatives.</p>