Confinement effects in homogeneous catalysis using well-defined supramolecular architectures

Advances in catalysis are central to the development of efficient chemical processes for the sustainable manufacturing of valuable chemicals. For homogeneous (transition) metal catalysts it is now well-recognized that the use of electronically and/or sterically tuned ligands can lead to enhanced catalytic performance of the corresponding metal complexes. Despite significant progress in the field of catalysis, there are still many reactions for which high catalytic efficiency cannot be achieved, and development of new approaches that lead to catalyst improvement are therefore important. In recent years, great efforts have been devoted to the development of supramolecular strategies as complementary approach to control catalytic performance. In this dissertation, emphasis is put on the effect of confinement on the catalytic performance in cobalt catalyzed cyclopropanation of alkenes and gold catalyzed cyclization reactions with the aim to demonstrate the importance of second coordination sphere effects in catalysis. Chapter 2 describes our efforts to encapsulate a catalytically active cobalt(II) meso-tetra(4-pyridyl)metalloporphyrin (Co−G) in a previously reported neutral organic cage. Chapter 3 reports the combined effects of the solvent and the cage on the catalytic performance in the cobalt catalyzed cyclopropanation of styrene. Chapter 4 shows our computational investigations on the effect of coordination of several axial donative ligands to [Co(TPP)] on the free energy barriers of the full catalytic cycle in cobalt-catalyzed cyclopropanation of styrene. Chapter 5 demonstrates how the peripheral cage substituents control the activity of a caged cobalt-porphyrin-catalyst in cyclopropanation reactions. Chapter 6 reports the synthesis of two novel M4L6 supramolecular cages based on BINAP ligands and their application in gold(I)-catalyzed cyclization reactions.