co.labore-A Genuine Collaboration between Arts and Science, Reflecting Viewpoints and Merging Skills.

Often chemists regard their scientific work as creative, when designing and synthesizing new molecules and larger assemblies. In this, we have to go through recurring stages of planning projects, doubting results, discarding ideas, and restarting them with a different approach in order to be successful in chemical research. From this point of view, can we fairly assume that these processes are analogous to the stages artists go through when creating art? In our efforts to strengthen reflective perspectives on what chemists are doing, the SFB 858 initiated a collaboration with the Academy of Fine Arts Münster. Additionally, we were aiming to enter into a dialogue about our research with a broader public.

Cooperative Effects in Chemistry-Collaborative Research Center SFB 858 in Münster.

Cooperative effects are found in various research areas in chemistry, many of which are currently explored within the Collaborative Research Center SFB 858 in Münster. This Editorial gives some insights into the field and an overview of the history of the Center and those who have contributed to the development of this fascinating multidisciplinary research area.

From Additivity to Cooperativity in Chemistry: Can Cooperativity Be Measured?

Cooperative effects can be observed in various research areas in chemistry; cooperative catalysis is well-established, the assembly of compounds on surfaces can be steered by cooperative effects, and supramolecular polymerization can proceed in a cooperative manner. In biological systems, cooperativity is observed in protein-protein, protein-lipid and protein-molecule interactions. Synergistic effects are relevant in frustrated Lewis pairs, organic multispin systems, multimetallic clusters and also in nanoparticles. However, a general approach to determine cooperativity in the different chemical systems is currently not known. In the present concept paper it is suggested that, at least for simpler systems that can be described at the molecular level, cooperativity can be defined based on energy considerations. For systems in which no chemical transformation occurs, determination of interaction energies of the whole system with respect to the interaction energies between all individual component pairs (subsystems) will allow determination of cooperativity. For systems comprising of chemical transformations, cooperativity can be evaluated by determining the activation energy of the synergistic system and by comparing this with activation energies of the corresponding subsystems that lack an activating moiety. For more complex systems, cooperativity is generally determined at a qualitative level.

Enantioselective cyclopropanation of enals by oxidative N-heterocyclic carbene catalysis.

Carbene catalysed redox activation of α,ß-unsaturated aldehydes is applied for generation of α,ß-unsaturated acyl azoliums which undergo cyclopropanation upon reaction with a sulfur ylide and an alcohol to give the corresponding cyclopropanecarboxylic acid esters. With chiral carbenes good to excellent diastereo and enantioselectivities are obtained.

Nitroxides: applications in synthesis and in polymer chemistry.

This Review describes the application of nitroxides to synthesis and polymer chemistry. The synthesis and physical properties of nitroxides are discussed first. The largest section focuses on their application as stoichiometric and catalytic oxidants in organic synthesis. The oxidation of alcohols and carbanions, as well as oxidative C-C bond-forming reactions are presented along with other typical oxidative transformations. A section is also dedicated to the extensive use of nitroxides as trapping reagents for C-centered radicals in radical chemistry. Alkoxyamines derived from nitroxides are shown to be highly useful precursors of C-centered radicals in synthesis and also in polymer chemistry. The last section discusses the basics of nitroxide-mediated radical polymerization (NMP) and also highlights new developments in the synthesis of complex polymer architectures.

Development of a convenient new synthetic route to [3]ferrocenophanones.

[3]Ferrocenophanone rac-8 was prepared by several non-Friedel-Crafts pathways starting from a Mannich-type coupling of 1,1'-diacetylferrocene followed by catalytic hydrogenation. Hydride abstraction from the resulting alpha-dimethylamino[3]ferrocenophane rac-14 with B(C6F5)3 followed by hydrolysis gave the ketone rac-8. Several variants of the Sommelet reaction, using ethylglyoxylate, formaldehyde or hexamethylenetetramine (urotropine) as the "oxidizing" reagent gave the alpha-[3]ferrocenophanone 8 in good to excellent yield. Some variants of these reactions were also used for the preparation of the pure enantiomer (R)-8. The electrochemical behaviour of 8 has been investigated and compared with related derivatives.