In situ Switching of Site-Selectivity with Light in the Acetylation of Sugars with Azo-Peptide Catalysts.

@article{Niedek2019InSS,
  title={In situ Switching of Site-Selectivity with Light in the Acetylation of Sugars with Azo-Peptide Catalysts.},
  author={Dominik Niedek and Frederik R. Erb and Christopher Topp and Alexander Seitz and Raffael C. Wende and Andr{\'e} K. Eckhardt and Jonas Kind and D. Robert Herold and Christina Marie Thiele and Peter Richard Schreiner},
  journal={The Journal of organic chemistry},
  year={2019}
}
We present a novel concept for the in situ control of site-selectivity of catalytic acetylations of partially protected sugars based on light as external stimulus using oligopeptide catalysts equipped with an azobenzene moiety. The isomerizable azobenzene-peptide backbone defines the size and shape of the catalytic pocket while the π-methyl-L-histidine (Pmh) moiety transfers the electrophile. Photoisomerization of the E- to the Z-azobenzene catalyst (monitored via NMR) with an LED (λ = 365 nm… 
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