Photoiniferter RAFT Polymerization of Optically Active Hydrophilic Vitamin B5 Analogous Methacrylamide

Abstract

Chiroptical polymers are interesting due to diverse applications in the field of chromatography, biomedicines, and catalysis. This study describes the synthesis of new types of optically active polymers of vitamin B5 analogous methacrylamide (B5AMA) using a photoiniferter polymerization approach at ambient temperatures. Enantiomers of B5AMA monomer ((R) and (S)) were prepared by the ring opening method and were characterized for their optical activity. The monomers were then polymerized by a photoiniferter polymerization approach using two different thiocarbonylthio (TCT) compounds as iniferters. Both TCTs showed controlled polymerization of B5AMA enantiomers and yielded polymers of opposite optical rotation. The enantiomeric polymers of B5AMA exhibited a complementary mirror-image Cotton effect to each other in the circular dichroism (CD) spectra, and ¹³C NMR analysis revealed the formation of syndiotactic polymer structures. To the best of our knowledge, this is the first study that depicts the successful synthesis of optically active macromolecules by a photoiniferter polymerization approach.