ChemInform Abstract: Superbase‐Catalyzed [4 + 2] Cycloaddition of Acetylenes to 3, 6‐Di(pyrrol‐2‐yl)‐1, 2, 4, 5‐tetrazine: A Facile Synthesis of 3, 6‐Di(pyrrol‐2‐yl)pyridazines. Issue 41 (19th September 2013)