Palladium-Catalyzed Insertion of an Allene into an Aminal: Aminomethylamination of Allenes by C-N Bond Activation

A new and atom-economic palladium-catalyzed aminomethylamination of allenes with aminals by C-N bond activation is described. This direct and operationally simple method provides a fundamentally novel approach for the synthesis of 1,3-diamines. Mechanistic studies suggest that a unique cationic pi-allylpalladium complex containing an aminomethyl moiety is generated as a key intermediate through the carbopalladation of the allene with a cyclometalated palladium-alkyl species.