Photoswitching of Basicity


  • M.V.P. and R.S.S. contributed equally to this work. We thank Petra Neubauer and Dr. Burkhard Ziemer (HU Berlin) for carrying out the single-crystal X-ray structure analyses. Generous support by the German Research Foundation (DFG, SPP 1179) and the Fonds der Chemischen Industrie, and initial funding by the Max Planck Society is gratefully acknowledged. We thank Wacker Chemie AG, BASF AG, Bayer Industry Services, and Sasol Germany for generous donations of chemicals.


original image

Smart bases: By using a photochromic azobenzene-derived blocking group, a piperidine base can be switched between a sterically shielded, inactive form and an accessible, reactive form (see picture; C dark gray, H light gray, O red, N blue). Thus, light can be used for the reversible external modulation of ground-state basicity and hence activity in general base catalysis.