Novel Arylindigoids by Late-Stage Derivatization of Biocatalytically Synthesized Dibromoindigo.
Christian SchnepelVeronica Isabel DoderoNorbert SewaldPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2021)
Indigoids represent natural product-based compounds applicable as organic semiconductors and photoresponsive materials. Yet modified indigo derivatives are difficult to access by chemical synthesis. A biocatalytic approach applying several consecutive selective C-H functionalizations was developed that selectively provides access to various indigoids: Enzymatic halogenation of l-tryptophan followed by indole generation with tryptophanase yields 5-, 6- and 7-bromoindoles. Subsequent hydroxylation using a flavin monooxygenase furnishes dibromoindigo that is derivatized by acylation. This four-step one-pot cascade gives dibromoindigo in good isolated yields. Moreover, the halogen substituent allows for late-stage diversification by cross-coupling directly performed in the crude mixture, thus enabling synthesis of a small set of 6,6'-diarylindigo derivatives. This chemoenzymatic approach provides a modular platform towards novel indigoids with attractive spectral properties.
Keyphrases
- ms ms
- optical coherence tomography
- liquid chromatography tandem mass spectrometry
- structure activity relationship
- hydrogen peroxide
- high throughput
- high performance liquid chromatography
- simultaneous determination
- magnetic resonance imaging
- gas chromatography mass spectrometry
- magnetic resonance
- water soluble
- single cell