Fe(acac)2/TBHP-promoted synthesis of 11-functionalized dibenzodiazepines via alkoxycarbonylation and carboxamidation of o-isocyanodiaryl amines.

A radical addition/cyclization reaction of o-isocyanodiaryl amines has been developed for the efficient synthesis of potentially bioactive dibenzo[b,e][1,4]diazepine-11-carboxylates and dibenzo[b,e][1,4]diazepine-11-carboxamides. This Fe(acac)2/TBHP-promoted radical cascade process involves an unexplored isocyanide addition and the following cyclization to form 11-functionalized dibenzodiazepines. Moreover, the alkoxycarbonylation and carboxamidation of o-isocyanodiaryl amines show broad substrate scope and good functional group compatibility under mild conditions.