O-Acylation of alcohols with acetic anhydride: J. Am. Chem. Soc., 117, 4413 (1995); Org. Synth., 77, 45 (1999), or acetic acid: Chem. Commun., 351 (1997). Aldol and Michael reactions of silyl enol ethers: Synlett, 472 (1993). Friedel-Crafts acylations: Synlett, 545 (1994); (in combination with LiClO4): Chem. Commun., 183 (1996). Fries rearrangement: J. Chem. Soc., Chem. Commun., 1527 (1995). Hetero Diels-Alder reactions: J. Chem. Soc., Chem. Commun., 1195 (1995). Catalyst for a one-pot synthesis of diaryl sulfoxides from arenes and thionyl chloride: Synlett, 784 (2002). Catalyst for methoxymethylation of alcohols with Dimethoxymethane: Tetrahedron Lett., 44, 6051 (2003). Selective addition of allyltrimethylsilane to aldehydes can be accomplished in the presence of a ketone: Synthesis, 1822 (1998).Catalyzes the Paal-Knorr synthesis of dialkylpyrroles from 1,4-diones under extremely mild, solvent-free conditions: Tetrahedron Lett., 47, 5383 (2006).For reviews of applications, see: Eur. J. Org. Chem., 15 (1999); Synlett, 2023 (1999).