Direct and Versatile Synthesis of Red-Shifted Azobenzenes.
A straightforward synthesis of azobenzenes with bathochromically-shifted absorption bands is presented. It employs an ortho-lithiation of aromatic substrates, followed by a coupling reaction with aryldiazonium salts. The products are obtained with good to excellent yields after simple purification. Moreover, with the presented methodology, a structurally diverse panel of different azobenzenes, including unsymmetric tetra-ortho-substituted ones, can be readily obtained, which paves the way for future development of red-light-addressable azobenzene derivatives for in vivo application.
Centre for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
Mickel J
0000-0002-7597-1229
MJ
Hansen
Centre for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
Michael M
MM
Lerch
Centre for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands. w.szymanski@umcg.nl.|Department of Radiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands. w.szymanski@umcg.nl.
Wiktor
0000-0002-9754-9248
W
Szymanski
Centre for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands. b.l.feringa@rug.nl.
Ben L
BL
Feringa
azobenzenes; diazonium salts; lithiation; photochromism; red shift