Es wird gezeigt,Dss sichquartäreCyclische Ammoniumsalze,Chinolin oder Isochinolin alsGrundkörper能力,Durch锂铝氢化物zu o-Dihydroderivaten reduzieren lassen。Diese Methode帽子,Gegenüberder klassischen Reduktionsmethode derartiger Verbindungen mit Natriumdithionit,Gewisse Vorteile。
The first Pd/Cu catalyzed selective C2-alkenylation of pyridines with internal alkynes has been developed via the pyridinium salt activation strategy. Importantly, the configuration of the product alkenylpyridines could be tuned by the choice of the proper N-alkyl group of the pyridinium salts, thus allowing for both the Z- and E-alkenylpyridines synthesized with good regio- and stereoselectivity.
synthesis of 2-formylpyrroles from pyridinium salts is reported. This protocol enables the synthesis of diversely substituted 2-formylpyrroles in good yields under operationally simple conditions. The detailed mechanistic studies reveal that the reaction proceeds via a novel H2O-triggered ring opening of the pyridinium salt and a subsequent intramolecularly nucleophilic addition sequence.