Dihydropyridine, dearomatized

Maron and coworkers reported in 2010 that bis(T -allyl)calcium reacts with pyridine to regioselectively afford a species with two anionic, dearomatized 1,4-dihydropyridide ligands, each resulting from the addition of an aUyl group to a coordinated pyridine.In excess pyridine, an octahedral complex could be isolated and structurally characterized by X-ray diffraction, which contains four intact pyridine Hgands, and the two anionic hgands in trans positions. Its reaction with E-Cl electrophiles generates the neutral N-protected 1,4-dihydropyridines and calcium chloride. 

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