Modeller av hydrogenas enzymers aktiva säten och outforskad fosfor-organisk kemi
Tidsperiod: 2016-01-01 till 2019-12-31
Budget: 4 400 000 SEK
In project A, we will synthesize bioinorganic model complexes of the [FeFe] and the [Fe] hydrogenase (H2ase) active sites. The role of the second coordination sphere and the protein matrix in [FeFe] H2ases and its effect on the stabilization of reactive intermediates in the catalytic cycle, in particular terminal hydrides, will be explored. Entirely unprecedented functional models of the [Fe] H2ase active site that contain organic hydride donors or acceptors in the second coordination sphere of the iron center will be developed and evaluated for their performance as proton reduction and hydrogen oxidation catalysts, respectively. For both types of H2ase mimics, detailed mechanistic studies will provide an increased understanding of the catalytic cycles which will ultimately lead to improved catalyst designs that function at the lowest possible overpotential.In project B, we will develop phospha-Wittig Horner reagents that are stabilized by bulky P-substituents instead of the currently used metal fragments. The result are new reagents that can convert carbonyl compounds to phosphaalkenes (P=C) in which the P-lonepair is available for subsequent metal complexations. Phosphinines, i.e. the P-analogues to pyridines, will be prepared following a new synthetic strategy that allows for complete regioselectivity of the substituents. We will explore the chemistry of suitably functionalized phoshinines in transition metal-catalyzed cross coupling reactions to afford elaborate compounds that are not available by any other method. The developed chemistry will provide reliable access to ligand frameworks and pi-conjugated materials with applications in homogenous catalysis and material science.