Our group has been working on enaminones for almost three decades (since 1986) and gained unprecedented experience in the field. In particular, the use of enaminones as versatile building blocks and reagents in heterocyclic synthesis has been studied in detail. Enaminones have also proven to be excellent reagents in combinatorial synthesis as well. Recently, we have turned our attention on application of enaminones in coordination and polymer chemistry.
Within a plethora of known structural analogues of peptides, the vinylogous peptides remain to be almost unexplored. Vinylogous α-peptides, where the C=C fragment is inserted between the carbonyl group and the α-carbon atom exhibit promising structural features and possible applications. On the other hand, we are the first to synthesized γ-peptides with a C=C fragment inserted into a peptide C–N. We developed a synthetic method where the enaminone moiety is temporary protected in a form of an isoxazoline and then released by hydrogenolytic cleavage of the N–O bond (EJOC 2014).
We can also prepare, combinatorially, a plethora of acacen-type ligands by transamination of 1,x-diamines with various enaminones. These compounds can coordinate metal ions, as demonstrated for Cu2+, Ni2+, Co2+ and Pd2+. The Cu(II)-complexes were successfully applied as catalysts in CuAIAC reactions (ACS Comb Sci 2017).
Transamination of bis-enaminones with 1,x-diamines were also found use in a mild amino–enaminone ‘click’ polymerisation method for the preparation of polyenaminones. The method allows for combinatorial preparation of structurally diverse polyenaminones. The obtained polymers were insoluble in most organic solvents, stable in diluted acids and bases, while degradable in concentrated hydrochloric acid at room temperature. They were thermally stable up to 200 °C and exhibited film-forming and UV-vis-shielding properties. Our aim and objectives in this field are the following:
Synthesis of enaminone-based vinylogous peptides.
Combinatorial Synthesis of Acacen-Type Ligands and Their Coordination Compounds.
Synthesis of polyenaminones by acid-catalysed amino–enaminone ‘click’ polymerisation.
