Complexes of coinage metals stabilized by N-heterocyclic carbenes: catalytic and biological activities
Abstract
Since the synthesis, the isolation, and the characterization of the first stable N-heterocyclic carbene (NHC) in
1991 by Arduengo and collaborators, this class of ligands has attracted the attention of researchers for the
synthesis of metal complexes active in different catalytic processes, and biological applications. The main
advantages of NHCs are the facile modulation of the electronic and steric characteristics, the ease of
manipulation, and interesting electron-donating properties.
During the last decades, the team I am part of has focused on the synthesis, characterization, and evaluation
of catalytic and biological properties of NHC metal complexes. Our interest keeps in the study of the influence
of substituents on nitrogen atoms and/or on the backbone might have on the performance of the complex
in catalysis and biological environment.
In this doctoral thesis, the catalytic and biological activity of N-heterocyclic carbene silver and gold complexes
will be examined. The catalytic performance will be evaluated in the A3
(aldehyde, amine, and alkyne)
coupling reaction, to lead propargylamines, and in the hydroamination of phenylacetylene with different
arylamines, to produce the corresponding ketoimines. Finally, it will evaluate the antibacterial and the
antitumoral activity of these complexes, against different bacterial strains and tumoral cells.
Chapter 1 gives an overview of N-heterocyclic carbene, the relative silver and gold complexes, and their
biological and catalytic applications.
Chapter 2 reports the obtained results and is organized as follows:
Sections 2.1-2.4 are reported the synthetic strategies and characterization of NHC pro-ligands and the
relative silver and gold complexes.
In Section 2.5, we have described the catalytic activity of silver and gold NHC complexes in the A3
-coupling
reaction with p-formaldehyde, benzaldehyde, and cyclohexanal.
Section 2.6 reported the results obtained by Au-NHC complex in the hydroamination reaction of
phenylacetylene.
Section 2.7 reported the biological activity of silver and gold complexes as potential antimicrobial and
tumoral compounds.
Chapter 3 gives an overview of the obtained results in A3
coupling reaction and hydroamination of alkynes,
and in the biological field, as antibacterial and antitumoral compounds, by silver and gold NHC, synthesized
in this doctoral thesis.
Chapter 4 described the experimental part. [edited by Author]