Hypervalent Iodine Reagent-Promoted Hofmann-Type Rearrangement/Carboxylation of Primary Amides

A novel transformation of primary amides to secondary amides promoted by hypervalent iodine reagents was developed. The hypervalent iodine reagent-mediated Hofmann-type rearrangement generated an isocyanate intermediate, which was subsequently trapped by an in situ generated carboxylic acid from the hypervalent iodine reagent to provide the corresponding secondary amides. This method provided a facile and efficient route for the synthesis of secondary amides from primary amides and also revealed novel reactivities of hypervalent iodine reagents.

Automated summary

A novel transformation of primary amides to secondary amides was developed using hypervalent iodine reagents, promoting a Hofmann-type rearrangement to generate an isocyanate intermediate which was then trapped by a carboxylic acid from the same reagent to provide the corresponding secondary amides. This method not only offers an easy and efficient route for synthesizing secondary amides from primary amides, but also reveals novel reactivities of hypervalent iodine reagents.