Investigating the Catalytic Efficiency of Supported NHC-Ag(I) Complexes in the Borono-Minisci Reaction

A series of supported N-heterocyclic carbene silver complexes (NHC-Ag(I)) were prepared and characterized as catalysts for the borono-Minisci reaction. After characterization, the synthesized catalysts were evaluated in batch mode to determine the reaction performance and kinetics. Interestingly, cyclic voltammetric analysis showed that the structure of both the complex and the ligand significantly influences the Ag(I)/Ag(II) redox potential and, in turn, the catalytic efficiency. Among the tested catalysts, the Si-supported NHC-Ag(I) 6 afforded the desired products in good to excellent yields in only 15 min, providing a complementary tactic to standard homogeneous approaches.In this paper we report the preparation, characterization, and evaluation of N-heterocyclic carbenes (NHC)-Ag(I) complexes as catalysts for the borono-Minisci reaction, a powerful and practical approach for the decoration of N-heterocycles. While it represents an unprecedented method, kinetic and cyclic voltammetric analyses evidenced how the complex structure influence the Ag(I)/Ag(II) redox potential and, in turn, the reaction efficiency and scope. image