Direct access to functionalized benzotropones, azepanes, and piperidines by reductive cross-coupling of α-bromo enones with α-bromo enamides.

The synthesis of functionalized azepenes and piperidines bearing an α-cycloheptenone or benzotropone derivative has been accomplished through direct reductive cross-coupling of α-bromo eneformamides or enecarbamates with highly versatile α-bromo benzotropone derivatives, under cobalt catalysis. The coupling products have been further elaborated to other synthetically useful aza-heterocyclic frameworks.