A Practical and Efficient Synthesis of Uniform Conjugated Rod-Like Oligomers.
Daniel HahnRebekka V SchneiderElena FoitzikMichael A R MeierPublished in: Macromolecular rapid communications (2021)
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).
Keyphrases
- mass spectrometry
- liquid chromatography
- high resolution
- high performance liquid chromatography
- randomized controlled trial
- gas chromatography
- electron transfer
- magnetic resonance
- capillary electrophoresis
- multiple sclerosis
- photodynamic therapy
- tandem mass spectrometry
- ms ms
- magnetic resonance imaging
- molecularly imprinted
- simultaneous determination
- room temperature