No abstract

A palladium-catalyzed multicomponent route to polycyclic pyrroles is described. Pd(PBu) was found to catalyze the coupling of (hetero)aryl iodides, two equivalents of carbon monoxide and alkyne-tethered imines into 1,3-dipoles (Münchnones), which undergo spontaneous, intramolecular 1,3-dipolar cycloaddition to form polycyclic pyrroles. The systematic variation of the alkyne, tethered-imine, or aryl iodide can allow the buildup of a range of pyrrole derivatives, where any of the substituents can be independently varied. In addition, the same palladium catalyst can be employed in an initial Sonogashira-type coupling with aryl iodides, which upon the addition of CO can allow the novel tandem catalytic, five component synthesis of diversely substituted products.

No abstract

Trifluoroacetic acid (TFA) is introduced as an effective catalyst for promotion of Biginelli reaction. 3,4-Dihydropyrimidin-2(1H)-one (-thione) derivatives (DHPMs) were simply and efficiently prepared using TFA catalyzed one-pot, three-component condensationβ-dicarbonyl compounds, aldehydes and urea (thio).