Tandem Condensation/Rearrangement Reaction of 2‐Aminohetarene N‐Oxides for the Synthesis of Hetaryl Carbamates

Abstract A new approach to hetaryl carbamates through a tandem condensation/rearrangement reaction of 2‐aminohetarene N ‐oxides was developed. The developed reaction is suitable for both five‐ and six‐membered heterocycles and proceeds through the condensation of 2‐aminohetarene N ‐oxide with trimethyl orthoformate followed by intramolecular N ‐oxide oxygen transfer. For five‐membered hetarene N ‐oxides (furoxans), the intramolecular rearrangement is catalyzed by a cyanide anion, while for six‐membered hetarene N ‐oxides (azines), Lewis acid catalysis is sufficient. The developed protocol is characterized by operational simplicity and high efficiency, resulting in carbamoyl derivatives in good and high yields. magnified image