ChemInform Abstract: A Phosphine‐Catalyzed Regioselective [3 + 2] Cycloaddition of Ethyl 5, 5‐Diarylpenta‐2, 3, 4‐trienoate with Aromatic Aldehydes and α, β‐Unsaturated Carbonyl Compounds. Issue 16 (April 2015)