DEAD-Promoted Oxidative Ugi-Type Reaction Including an Unprecedented Ugi Amidation Assisted by Dicarboxylic Acids

A mild and metal-free DEAD-promoted (DEAD = diethyl azodicarboxylate) oxidative Ugi-type reaction of tertiary amines has been demonstrated. The reaction gives easy access to α-amino amides and imides with diverse functional groups in good isolated yields. This Ugi-type approach achieves an unprecedented synthesis of α-amino amide analogues with the assistance of dicarboxylic acids, and not water, for the introduction of the carbonyl oxygen atom of the amide moiety. Mechanistic studies indicated that the dicarboxylic acids may readily undergo an intramolecular annulation, instead of the Mumm rearrangement, to give the desired amide with one molecule of anhydride released.