Molecular Recognition-Based Catalysis in Nucleophilic Aromatic Substitution: A Mechanistic Study

Nuno Basilio, Luis García-Río, Ángeles Peña-Gallego, and Moisés Pérez-Lorenzo
New J. Chem., 2012, 36, 1519–1526

 

Nucleophilic aromatic substitution for nitro-activated substrates in the presence of glymes and crown ethers is reported. The kinetic study reveals the many-sided nature of the polyether-catalyzed SNAr mechanism as well as the main features affecting the course of the reaction. Thus, the process can be efficiently controlled by the catalyst through a molecular-recognition process, being also strongly dependent on the electronic structure of the substrate and, therefore, giving rise to a versatile reaction system. The kinetic model proposed herein allows quantifying the fractions of reaction proceeding through the different routes. Information on the nature of the host–guest interaction between the catalyst and the substrate will also be extracted.