Asymmetric catalytic emulsion polymerization in chiral micelles

Abstract

Achiral substituted acetylene monomers undergo aqueous catalytic emulsion asymmetric polymerizations in chiral micelles consisting of SDS and amino acid, providing optically active helical polymer emulsions. The asymmetric polymerizations lead to one-handed helical polymers, which are the origin of the optical activity of polymer emulsions.

Helix‐Sense‐Selective Polymerization of Achiral Substituted Acetylenes in Chiral Micelles

“…A chiral emulsifier, dodecylphenylalanine (d-or l-DPA), was synthesized from phenylalanine and dodecanoyl chloride. [19,20] This is also true Scheme 1. The complex aqueous solutions exhibited optical activity according to the positive (assigned to d-DPA) and negative (l-DPA) circular dichroism (CD) signals at around 400 nm in Figure S1 (Supporting Information), while d-and l-DPA showed CD signals at approximately 230 nm (d-DPA, positive; l-DPA, negative; inset in Figure S1).…”

“…Chiral micelles [11,12] have been widely applied for chiral recognition, [13] chiral separation, [14] and enantioselective synthesis. To confirm this hypothesis, we prepared optically active nanoparticles consisting of substituted helical polyacetylenes by asymmetric polymerization of achiral monomers in chiral micelles, [19] whereas nonasymmetric polymerizations occurred in achiral micelles and provided nanoparticles without optical activity. To confirm this hypothesis, we prepared optically active nanoparticles consisting of substituted helical polyacetylenes by asymmetric polymerization of achiral monomers in chiral micelles, [19] whereas nonasymmetric polymerizations occurred in achiral micelles and provided nanoparticles without optical activity.…”

Preparation of Optically Active Nanoparticles by Emulsification of Preformed Helical Polymers

“…CD spectroscopy has been proven straightforward and efficient to identify the secondary structures of helical polymers and polymer emulsions based on helical polymers. [15][16][17][18] The CD and UVVis spectra of the emulsion from polymer 1 are illustrated in Figure 2. As can be seen from Figure 2A, CD signals tend to be stronger in intensity as the content of SDS was increased.…”

“…To circumvent the limitations and to prompt the relevant application research, we have prepared for the first time a unique category of nanoparticles consisting of helical substituted polyacetylenes. [15][16][17] Further, we succeeded in the preparation of core/shell nanoparticles where the core was based on helical polyacetylenes and the shell was constituted by vinyl polymers. [18] Such (core/shell) nanoparticles exhibited interesting optical activities due to the core-forming polyacetylenes adopting helical structures of preferential handedness.…”

Micelle-provided microenvironment facilitating the formation of single-handed helical polymer-based nanoparticles

“…In the preceding studies, we established the first helix-sense-selective polymerization in chiral micelles 16,17 and the first helix-sense-selective precipitation polymerization 18 for constructing optically active polyacetylene particles. helix-sense-selective polymerizations (HSSPs), 15 which are of great importance for realizing the same target by using achiral monomers instead of expensive chiral counterparts.…”