The nucleophilicity of N-unsubstituted imines, which were generated from alkyl azides by a ruthenium-catalyzed reaction, was investigated in the reaction with acid anhydrides. The initial products were N-acylimines, which isomerized to the corresponding enamides. Heating or triethylamine facilitated the isomerization of N-acylimines that are stable at room temperature. A wide range of acyclic and cyclic enamides containing various functional groups was successfully synthesized under mild conditions. In addition to acetic anhydride, various acid anhydrides were applicable. From the reaction with cyclic anhydrides, enamides containing carboxylic acid group were obtained.

The esters of 1,2-azido alcohols were transformed into α-amido ketones without external oxidants through the Ru-catalyzed formation of N-H imines with the liberation of N2 followed by intramolecular migration of the acyl moiety. A wide range of α-amido ketones were obtained, and one-pot transformation into the corresponding oxazoles (or a thiazole) was demonstrated.

Enamides were synthesized by a ruthenium‐catalyzed one‐pot, one‐step procedure from alkyl azides and acid anhydrides. The substrate scope includes not only secondary azides, but also primary aliphatic ones to give a wide range of enamides containing various functional groups. This one‐step procedure was based on the newly discovered activity of Severin's diruthenium complex ([Cp^RuCl2]2: Cp^=η5‐1‐methoxy‐2,4‐di‐tert‐butyl‐3‐neopentylcyclopentadienyl) for the transformation of alkyl azides into the corresponding N−H imine intermediates in ionic liquids. The formation of ruthenium tetrazene complexes was observed in the stoichiometric reaction of Severin's complex with alkyl azides, which acted as the catalyst for the formation of N−H imine intermediates.

Au niqueo ne-pot synthesiso fc yclic cis-1,2-aminoa lcoholsf rom trans-1,2-azido alcohol precursors wasd eveloped. Thek ey step is highlighted by the stereoselective reductiono ft he cyclic aalkoxy imines, which could be prepared from the corresponding azides by ruthenium catalysisu nder photolytic conditions.R emarkably,t his unprecedented reaction pathway offers as tereodivergent access to structurallyd iverse cyclic1 ,2-aminoa lcohols.

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