Multidirectional Cobalt-Catalyzed Diels–Alder/1,4-Hydrovinylation Sequences

The combination of two powerful cobalt-catalyzed carbon–carbon bond forming transformations, namely, the Diels–Alder and the 1,4-hydrovinylation reaction, in a tandem or a sequential one-pot procedure, opened up a concise and efficient route to polysubstituted aromatic systems and cyclohex-3-enone derivatives. Furthermore, ozonolysis of the latter products led to polycarbonyl compounds with tailored carbonyl group distances which could be characterized via their respective BF₂-borinane complexes. The cobalt catalysts tolerated several functional groups, and a flexible approach to polyfunctionalized compounds in concise fashion was described.