Efficient Synthesis of Cyclic Poly(ethylene glycol)s under High Concentration Conditions by the Assistance of Pseudopolyrotaxane with Cyclodextrin Derivatives.
ACS Macro Lett
; 12(11): 1498-1502, 2023 Nov 21.
Article
em En
| MEDLINE
| ID: mdl-37874266
ABSTRACT
An efficient synthesis of cyclic polymers (CPs) is in high demand due to their unique properties. However, polymer cyclization generally occurs at low concentrations (0.1 g/L), and the synthesis of CPs at high concentrations remains a challenge. Herein an efficient cyclization of poly(ethylene glycol) (Mn = 2000 g/mol, 4000 g/mol) (PEG-2k, PEG-4k) in high concentration (80 g/L) is realized by the assistance of pseudopolyrotaxane (pPRx). Water-soluble pPRx with a U-like-shape inclusion motif is prepared by mixing the 2-hydroxypropyl-γ-cyclodextrin (HPγCD) and PEG with (E)-3,4,5-trimethoxycinnamate (TCA-PEG-2k, TCA-PEG-4k). Subsequent irradiation of the pPRx solution (10-80 g/L) by UV light gives cyclic polymers through the intramolecular [2 + 2] photocycloaddition of the cinnamoyl moieties. The photoreaction of TCA-PEG-2k in the pPRx system gives cyclic monomers (C-1mer) as major products with a yield of 66% at 80 g/L. Additionally, the cyclization of TCA-PEG-4k also gives C-1mer as major products with a yield of 45% at a concentration of 80 g/L.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
ACS Macro Lett
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Japão