A highly-efficient palladium-catalyzed aminocarbonylation/SNAr approach to dibenzoxazepinones†
A convenient procedure for the synthesis of dibenzoxazepinones has been developed. Utilizing the protocol of one-pot palladium-catalyzed aminocarbonylation/aromatic nucleophilic substitution (SNAr) sequence, with 2-aminophenols and 2-bromofluorobenzenes as the substrates, the desired dibenzo[b,e][1,4]oxazepin-11(5H)-ones were prepared in moderate to excellent yields. The broad substrate scope and functional group tolerance of the reaction makes this approach a practical method for the synthesis of valuable dibenzoxazepinone and its derivatives. Mechanistic studies suggest that aminocarbonylation proceeds prior to SNAr.