A Robust Porous Quinoline Cage: Transformation of a [4+6] Salicylimine Cage by Povarov Cyclization
Pierre-Emmanuel Alexandre, Wen‐Shan Zhang, Frank Röminger, Sven M. Elbert, Rasmus R. Schröder, Michael Mastalerz
Abstract
Abstract Porous shape‐persistent organic cages have become the object of interest in recent years because they are soluble and thus processable from solution. A variety of cages can be achieved by applying dynamic covalent chemistry (DCC), but they are less chemically stable. Here the transformation of a salicylimine cage into a quinoline cage by a twelve‐fold Povarov reaction as the key step is described. Besides the chemical stability of the cage over a broad pH regime, it shows a unique absorption and emission depending on acid concentration. Furthermore, thin films for the vapor detection of acids were investigated, showing color switches from pale‐yellow to red, and characteristic emission profiles.