Tandem Cycloaddition-Cyclopentannulation Processes of 2-Aminobuta-1,3-dienes and Fischer Alkynylcarbene Complexes as a Tool for the Preparation of Complex Polycyclic Scaffolds - Barluenga, José; Aznar, Fernando; Barluenga, Sofía; Martín, Alfredo; García-Granda, Santiago; Martín, Eduardo (Synlett, 1998)