Visible light photoredox catalyzed inter- and intramolecular C-H functionalization reactions of tertiary amines have been developed. Oxygen was found to act as chemical switch to trigger two different reaction pathways and to obtain two different types of products from the same starting material. In the absence of oxygen, the intermolecular addition of N,N-dimethyl-anilines to electron-deficient alkenes provided γ-amino nitriles in good to high yields. In the presence of oxygen, a radical addition/cyclization reaction occurred which resulted in the formation of tetrahydroquinoline derivatives in good yields under mild reaction conditions. The intramolecular version of the radical addition led to the unexpected formation of indole-3-carboxaldehyde derivatives. Mechanistic investigations of this reaction cascade uncovered a new photoredox catalyzed C-C bond cleavage reaction.

A transition metal-free Heck-type cyclization/isomerization reaction has been developed. Mediated by potassium tert-butoxide and phenanthroline a variety of benzofuran derivatives have been synthesized.

X-ray photoelectron spectroscopy was used to characterize modified surfaces of a biomedically important polymer, poly(ethylene terephthalate). Several modification schemes were investigated and direct silanization with 3-aminopropyltriethoxysilane was found to be the optimum procedure, resulting in an aminated surface. Surface coverage of up to 100% was achieved with retention of the polymeric structural integrity. Further activation of the silanized surface was accomplished with two cross-linkers, glutaraldehyde and sebacoyl chloride. A simple biomolecule, L-cysteine, was successfully immobilized onto a surface pre-treated with 3-aminopropyltriethoxysilane and glutaraldehyde, with a coverage of 42%.

A novel strategy for site-specific and covalent attachment of proteins has been developed, intended for robust and controllable immobilization of histidine (His)-tagged ligands in protein microarrays. The method is termed chelation assisted photoimmobilization (CAP) and was demonstrated using human IgG-Fc modified with C-terminal hexahistidines (His-IgGFc) as the ligand and protein A as the analyte. Alkanethiols terminated with either nitrilotriacetic acid (NTA), benzophenone (BP), or oligo(ethylene glycol) were synthesized and mixed self-assembled monolayers (SAMs) were prepared on gold and thoroughly characterized by infrared reflection absorption spectroscopy (IRAS), ellipsometry, and contact angle goniometry. In the process of CAP, NTA chelates Ni(2+) and the complex coordinates the His-tagged ligand in an oriented assembly. The ligand is then photoimmobilized via BP, which forms covalent bonds upon UV light activation. In the development of affinity biosensors and protein microarrays, site-specific attachment of ligands in a fashion where analyte binding sites are available is often preferred to random coupling. Analyte binding performance of ligands immobilized either by CAP or by standard amine coupling was characterized by surface plasmon resonance in combination with IRAS. The relative analyte response with randomly coupled ligand was 2.5 times higher than when site-specific attachment was used. This is a reminder that also when immobilizing ligands via residues far from the binding site, there are many other factors influencing availability and activity. Still, CAP provides a valuable expansion of protein immobilization techniques since it offers attractive microarraying possibilities amenable to applications within proteomics.

A convergent catalysis approach has been developed. The combined metal-catalyzed and organocatalyzed cascade consists of two oxidations, an aza-Michael addition and an aldol condensation, and involves a multicatalysis approach to provide 1,2-dihydroquinolines in a highly enantioselective fashion.