The significant research progress (from 2011 to 2021) in artificial helical polymers, such as polyacetylenes, polyisocyanides, polycarbenes, etc., in the fields of asymmetric organocatalysis is described.

Three novel enantiopure phenyl isocyanide monomers with BH3-protected phosphine functional group were designed and synthesized. Polymerization of these monomers using a alkyne-Pd(II) complex as a catalyst led to the formation of respective helical polyisocyanides in high yields with controlled molecular weights (M_ns) and narrow molecular weight distributions (M_w/M_ns). Removing the protecting BH3 groups afforded helical poly(phenyl isocyanide)s bearing phosphine pendants. Thanks to the chiral induction of monomer, the isolated helical polyisocyanides showed high optical activity, as revealed by circular dichroism (CD) and absorption spectroscopies and polarimetry. The helical structures of these polymers were quite stable in various organic solvents with different polarities and in a wide temperature range. Moreover, these helical polymers could be used as organocatalysts and showed good performance in enantioselective cross Rauhut-Currier reaction. The enantiomeric excess (ee) values of the isolated products of cross Rauhut-Currier reaction could be up to 90%. The polymer organocatalysts could be easily recovered from the reaction mixtures and reused at least five times in the reaction without significant loss of their enantioselectivities and catalytic activities.

The design and synthesis of highly water-soluble conjugated block copolymers with multi-responsive properties are of great interest due to the copolymers’ potential as solution processable semiconductor materials. Herein, we report a one-pot synthesis of well-defined block copolymers containing conjugated poly(3-hexylthiophene) (P3HT) and poly(phenyl isocyanide) (PPI) bearing hydrophilic tri(ethylene glycol) monomethyl ether chains. These block copolymers have good solubility in water and exhibit excellent thermoresponsive behavior. The lower critical solution temperature (LCST) in water can be facilely tuned through varying the concentration or polymer composition. Moreover, the optical properties of the block copolymer are dependent on the solvents used owing to the distinct self-assembled structures. In CHCl₃, the P3HT-b-PPI block copolymer exhibits pH-responsive behavior with the emission color changing between orange and blue upon alternate additions of trifluoroacetic acid and triethylamine. In addition, such block copolymers are revealed to be good materials for live cell imaging.