A couple of weeks ago, I heard one of the most interesting lectures of the past year. Prof. Alcarazo, now at the University of Göttingen, was visiting our department as the external examiner of one of Doug Stephan’s PhD students. From his talk, I learned about the surprising reactivity of thiourea, known in all sorts of roles – from heterocycle synthesis to asymmetric catalysis. The novel reactivity shown in Figure has its origins in Roald Hoffman’s teachings on the power of isolobal relationships in chemistry. Alcarazo and his students have extended this enduring concept to the “sulfur version” of hypervalent iodine reagents. As it turns out, a lot of reactions known in organoiodine chemistry can now be carried out using significantly more user-friendly organosulfur compounds, many of which are accessible from thiourea derivatives using a couple of trivial transformations. By way of an example, I am showing the cyanation of N-methyl indole.
amphoteros 