A Practical and Efficient Synthesis of Uniform Conjugated Rod-Like Oligomers.
Macromol Rapid Commun
; 42(9): e2000735, 2021 May.
Article
em En
| MEDLINE
| ID: mdl-33646627
ABSTRACT
Herein, a more practical and efficient synthesis protocol for the preparation of uniform rod-like oligo(1,4-phenylene ethynylene)s (OPE)s is presented. Applying an iterative reaction cycle consisting of a decarboxylative coupling reaction and a saponification of an alkynyl carboxylic ester, a uniform pentamer is obtained in ten steps with 14% overall yield. The copper-free conditions prevent homocoupling until the trimer stage, resulting in a significantly easier work-up of the products. Homocoupling is observed from the tetramer stage on, but a simple variation of the work-up procedure also yields the uniform tetramer and pentamer. A thorough comparison with the commonly used and described Sonogashira approach reveals that with the new presented strategy, OPEs can be built in similar overall yield, but easier purification and in a quarter of the time. All oligomers are fully characterized by proton and carbon nuclear magnetic resonance spectroscopy (NMR), mass spectrometry (MS), size-exclusion chromatography (SEC), and infrared spectroscopy (IR).
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Base de dados:
MEDLINE
Assunto principal:
Espectroscopia de Ressonância Magnética
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article