ChemInform Abstract: Cycloaddition of N‐Sulfonylpyridinium Imides and Isoquinolinium Imides with Acetylenedicarboxylates: A Practical Synthesis of Pyrazolo[1, 5‐a]pyridine and Pyrazolo[5, 1‐a]isoquinolines Derivatives. Issue 4 (31st January 2013)