Hf(OTf)4-Doped Me3SiCl-Catalyzed Aminomethylation of Arenes with N,O-Acetals: Facile Approach to Non-Natural Aromatic Amino Acid Precursors - Sakai, Norio; Asano, Junichi; Shimano, Yuta; Konakahara, Takeo (Synlett, 2007)