1,3-Dipolar Cycloaddition of Nitrile Imines with Functionalized Acetylenes: Regiocontrolled Sc(OTf)3-Catalyzed Synthesis of 4- and 5-Substituted Pyrazoles - Bonini, Bianca Flavia; Franchini, Mauro Comes; Gentili, Denis; Locatelli, Erika; Ricci, Alfredo (Synlett, 2009)