Synthesis of Allenamides and Structurally Related Compounds by a Gold-Catalyzed Hydride Shift Process

A new procedure for the synthesis of allenamides and structurally related compounds is reported. Under gold catalysis, a series of ynamides possessing a benzyloxy group at the propargylic position were efficiently converted into the corresponding allenamides following a 1,5 hydride shift process. The scope of the reaction was shown to be extremely broad allowing the formation of -mono or -disubstituted allenes possessing various functional groups. Notably, and in contrast to previously reported methods, not only N-allenyl sulfonamido but also urea, phosphonamido and the rarely studied phthalimido, pyrrolo, indolo and carbazolo derivatives could be readily and efficiently accessed.