This review highlights a recent study on allenic compounds by the author's group. In the first section, the organocopper-mediated ring-opening reaction of ethynylaziridines and palladium-catalyzed reductive synthesis of allenes are described. In the second section, palladium-catalyzed stereoselective cyclization of allenes, including the tandem reaction, leading to aziridines, pyrrolidines, benzoisoindoles, and cyclopropanes is presented. The final section reviews aziridination and medium-ring formation due to the intramolecular reaction of bromoallenes. The latter reaction is based on the author's recent discovery that bromoallenes can act as allylic dication equivalents in the presence of a palladium catalyst and alcohol.