Magnesium Perchlorate as Efficient Lewis Acid: A Simple and Convenient Route to 1,4-Dihydropyridines - Bartoli, Giuseppe; Babiuch, Krzysztof; Bosco, Marcella; Carlone, Armando; Galzerano, Patrizia; Melchiorre, Paolo; Sambri, Letizia (Synlett, 2007)