Novel synthesis of porous one-handed helical poly(substituted phenylacetylene) bearing betulin derivatives pendant groups

A novel substituted phenylacetylene with a pendant betulin derivative group was designed and synthesized successfully, and the chemical structure of the monomer was confirmed by nuclear magnetic resonance spectroscopy (NMR, 1 H, 13 C), high-resolution mass spectrometry (HRMS) and Fourier transform infrared spectroscopy (FTIR). The obtained monomer was further polymerized in an achiral [Rh(nbd)Cl] 2 /triethylamine (TEA) catalytic system, and the resulting polymer exhibited a strong Cotton effect at the main-chain absorption regions in the circular dichroism (CD) spectra. This one-handed helical backbone was induced by the chiral source on the side chain and maintained by the rigid betulin derivative pendant flats. Furthermore, the rigid betulin derivatives also contributed to the porous morphology and perfect thermal stability of the polymer. This study will provide a new method for preparing porous chiral polymers as efficient separation materials to solve practical issues.