Synthesis of Orthogonally Protected Angular Nitrogen Polyheterocycles via CpCo-Catalyzed Pyridine Formation - Miclo, Yves; Garcia, Pierre; Evanno, Yannick; George, Pascal; Sevrin, Mireille; Malacria, Max; Gandon, Vincent; Aubert, Corinne (Synlett, 2010)