2,2′‐Bis(arylamino)‐1,1′‐biaryls as Building Blocks for the Synthesis of Dibenzo[d,f][1,3]diazepines, Dibenzo[d,f][1,3]diazepinones, and Dibenzo[c,e][1,2,7]thiadiazepine 6‐Oxides

Abstract

The iron‐catalyzed oxidative C−C homocoupling of diarylamines affords 2,2′‐bis(arylamino)‐1,1′‐biaryls which represent crucial synthetic building blocks for an access to a range of seven‐membered heterocyclic ring systems. Reaction with paraformaldehyde, diphenyl carbonate, and diphenyl sulfite as efficient 1,1‐dielectrophiles led to dibenzo[d,f][1,3]diazepines, dibenzo[d,f][1,3]diazepinones, and dibenzo[c,e][1,2,7]thiadiazepine 6‐oxides. The synthetic procedures enable short and practical routes to these 1,3‐diazepine derivatives under mild reaction conditions and with a high tolerance of various functional groups.