Photo-crosslinked polymer cubosomes as a recyclable nanoreactor in organic solvents?

Polymer Chemistry Pub Date: 2021-04-13 DOI: 10.1039/D1PY00115A

Abstract

Polymer cubosomes are an emerging class of mesoporous structures formed by the solution self-assembly of block copolymers (BCPs) with a highly asymmetric block ratio. The internal nanochannel networks of a polymer cubosome provide a large surface area and internal volume to accommodate catalysts, which makes this reticulated porous structure a promising candidate for nanoreactors. Herein, we report the synthesis of BCPs composed of poly(ethylene glycol) (PEG) hydrophilic and the poly(styrene-co-pentafluorostyrene) (P(pFS-co-Sty)) hydrophobic block. The pentafluorophenyl groups in the hydrophobic block could be easily functionalized with N3 groups by post-polymerization modification. The binary mixture of branched-linear and catalyst-functionalized linear BCPs self-assembled into polymer cubosomes having surface-tethered catalysts, which were crosslinked by UV irradiation. We show that the resulting polymersome nanoreactors could catalyze the asymmetric aldol reaction of 4-nitrobenzaldehyde and acetone in organic solvents to yield (R)-4-hydroxy-4-(4-nitrophenyl)butan-2-one at an enhanced rate compared to the reaction catalyzed by molecular catalysts. These robust nanoreactors performed catalysis repeatedly after multiple recycling without losing their catalytic efficiency and structural integrity.

Graphical abstract: Photo-crosslinked polymer cubosomes as a recyclable nanoreactor in organic solvents
Recommended Literature