Monolayers of fluorinated light-driven molecular motors were synthesized and immobilized on gold films in an altitudinal orientation via tripodal stators. In this design the functionalized molecular motors are not interfering and preserve their rotary function on gold. The wettability of the self-assembled monolayers can be modulated by UV irradiation.

In complex organisms, cells are often dependent on their extracellular matrix (ECM) for structural integrity, the mechanical properties of tissues, and for signaled regulation of cellular processes including adhesion, migration, growth, secretion, gene expression and apoptosis. Achieving dynamic control, i.e. by using an external stimulus, over the interactions between cells and artificial interfaces holds considerable promise in tissue engineering, medicine, cell biology and immunology. For example, improved spatial control over cell-surface interaction is potentially useful in the design of cell-based screening devices. Dynamic control over SAMs for cell adhesion provides an additional handle to direct and study the attachment of cells to surfaces, e.g., in studying cell spreading from a predetermined pattern in order to screen the cytotoxicity of drug candidates. However, 'reversible' control of cell adhesion onto substrates is an area that is still in its infancy. In this critical review recent developments in cell adhesion of mammalian cells to SAM-modified surfaces, the physical properties of which can be controlled by an external stimulus, e.g. by light, electrochemistry, etc., are discussed (118 references).

Several miRNAs have been reported to be associated with immunoglobulin heavy chain (IgH) mutation and ZAP-70 expression status in blood samples of B-cell chronic lymphocytic leukaemia/small lymphocytic lymphoma (B-CLL/SLL). In the bone marrow and lymphoid tissues, proliferation centres (PCs) represent an important site of activation and proliferation of the neoplastic cells, suggesting that these tissues better reflect the biology of CLL than circulating blood cells. We collected 33 lymph nodes and 37 blood CLL samples and analysed IgH mutation status and ZAP-70 expression status. Expression of 15 miRNAs was analysed by qRT-PCR and RNA-ISH. Sixty-three per cent of the lymph node cases contained mutated IgH genes and 49% of the lymph node cases were ZAP-70-positive, and a significant correlation was observed between ZAP-70 expression and IgH mutation status. Of the blood CLL samples, 49% contained mutated IgH sequences. The miRNA expression pattern in CLL lymph node and blood samples was very similar. Three of 15 miRNAs (miR-16, miR-21, and miR-150) showed a high expression level in both blood and lymph node samples. No difference was observed between ZAP-70-positive or -negative and between IgH-mutated or unmutated cases. No correlation was found between miR-15a and miR-16 expression levels and 13q14 deletion in the blood CLL samples. RNA in situ hybridization (ISH) revealed strong homogeneous staining of miR-150 in the tumour cells outside the PCs. In reverse BIC/pri-miR-155 expression was observed mainly in individual cells including prolymphocytes of the PCs. This reciprocal pattern likely reflects the different functions and targets of miR-150 and miR-155.

A series of first-generation light-driven molecular motors with rigid substituents of varying length was synthesized to act as "molecular stirrers". Their rotary motion was studied by (1)H NMR and UV-vis absorption spectroscopy in a variety of solvents with different polarity and viscosity. Quantitative analyses of kinetic and thermodynamic parameters show that the rotary speed is affected by the rigidity of the substituents and the length of the rigid substituents and that the differences in speed are governed by entropy effects. Most pronounced is the effect of solvent viscosity on the rotary motion when long, rigid substituents are present. The α values obtained by the free volume model, supported by DFT calculations, demonstrate that during the rotary process of the motor, as the rigid substituent becomes longer, an increased rearranging volume is needed, which leads to enhanced solvent displacement and retardation of the motor.

Here we report a photochemical and kinetic study of the thermal relaxation reaction of a double azobenzene system, in which two azobenzene photochromic units are connected via a phenyl ring. Upon UV irradiation, three thermally unstable isomers are formed. Kinetic studies using arrayed (1)H-NMR spectroscopy revealed four distinct barriers for the thermal reversion to the stable isomer. The double isomerised Z,Z-2 can revert thermally to the E,E-2 isomer via either of two isomerisation pathways. The thermal Z to E isomerisations are not significantly affected by the state of the neighbouring azo-switching unit in the meta position. These findings are supported by quantum chemical calculations on the thermal Z to E isomerisation.

Enantioselectivities up to >99% ee were achieved in the rhodium-catalyzed asymmetric hydrogenation of N-formyl dehydroamino esters using monodentate phosphoramidites as chiral ligands. The substrates were synthesized by condensation of methyl isocyanoacetate with a range of aldehydes and with cyclohexanone. A highly convenient multigram scale one step synthesis of methyl 2-(formamido)acrylate was developed. This compound was used in the synthesis of methyl 2-(formamido)cinnamate via a solvent free Heck reaction. Moreover, full conversion and >99% ee were obtained in 1 h in the hydrogenation of methyl 2-(formamido)acrylate with 0.2 mol % catalyst and 2 bar hydrogen pressure. The versatility of the formyl protection was established by its removal under mild conditions.

We report a straightforward method for the rapid conversion of thio-ethers to thio-acetates using TiCl4, in good to excellent yields. The reaction conditions tolerate a variety of functional groups, including halide, nitro, ether, thiophene and acetylene functionalities. A catalytic variant of this reaction is also described.

The development of chiral transition metal complexes for asymmetric catalysis has seen the concomitant emergence of strategies for their recovery and recyclability in order to render these catalysts economically interesting for industrial applications. In particular, the synthesis of enantioselective metallodendrimers is an interesting approach that combines the advantages of both homogeneous and heterogeneous catalysis without violating the highly active and stereoselective properties of the parent catalyst. In this chapter, a comprehensive overview of the state of the art in enantioselective catalytic dendrimers is given, with an emphasis on the catalytic and recyclability properties of these macromolecules.