How would you describe your research?For over 20 years, the group of Armin Bçrner has been engaged in hydroformylation. Industrially relevant problems have been addressed ranging from the synthesis of new ligands to the formation of catalysts, stability investigations of ligands and development of in situ high-pressure NMR and IR techniques. A highlight was the inauguration of the 3-PH (3-propylheptanol) plant in 2009 by Evonik Industries AG in Marl, with an annual production of 60 000 t, benefiting from results achieved by the Rostock group.How did the collaboration on this project start?Although large-scale hydroformylation is well-established, it is rarely found in small companies. Thus, a collaboration was initiated with Jhonny JimØnez-Pinto, who works at the interface between research and technical application at Miltitz Aromatics, specialists in the production of flavours and aroma compounds. As aldehydes are the most important class of aroma compounds, a fruitful collaboration was started. A problem in technical hydroformylation is the current high price of carbon monoxide, which would be overcome partly by the development of a syngas-free hydroformylation process. How did the other collaborators get involved?To cover the small-scale hydroformylation of aroma compounds, Elena V. Gusevskaya, one of the leading chemists in this field, was contacted. The rich Brazilian nature provides ideal resources for the investigation of catalytic transformation of natural compounds, such as pleasant-smelling terpenes. Elena agreed immediately to take part, facilitating the completion of the Review. What are the main challenges in your research?Small-scale hydroformylation, especially for the production of aroma compounds, remains a challenge. The main problems are insufficient regio-and stereochemistry and high prices of catalysts and carbon monoxide. Hydroformylation on the small industrial scale will thus be a future focus of in academic and industrial chemists. Moreover, owing to pending regulations on the reduction of allergenic components in perfumes based on natural compounds, processes for synthetic non-allergenic aroma compounds will gain increasing importance.Invited for this month's front cover is a transatlantic collaboration between academic and industrial researchers in Germany and Brazil. The image shows how the works of Coco Chanel, creator of fragrance Chanel N o 5, and Otto Roelen, discoverer of the hydroformylation reaction, overlapped: the perfume had a high proportion of linear aldehydes. See the Review itself at http://dx

Invited for this month’s front cover is a transatlantic collaboration between academic and industrial researchers in Germany and Brazil. The image shows how the works of Coco Chanel, creator of fragrance Chanel No 5, and Otto Roelen, discoverer of the hydroformylation reaction, overlapped: the perfume had a high proportion of linear aldehydes. See the Review itself at .

Breslow intermediates that bear radical‐stabilizing N substituents, such as benzyl, cinnamyl, and diarylmethyl, undergo facile homolytic CN bond scission under mild conditions to give products of formal [1,3] rearrangement rather than benzoin condensation. EPR experiments and computational analysis support a radical‐based mechanism. Implications for thiamine‐based enzymes are discussed.

Review: 200 refs.