Unexpected Base-Promoted Synthesis of Tetrasubstituted Furans via Palladium-Catalyzed Oxidation and Cyclization of Carbon-Carbon Triple Bond with Molecular Oxygen.

A new approach to the synthesis of tetrasubstituted furans using aromatic alkynes catalyzed by PdCl2 in DMA (N,N-dimethylacetamide)- H2O with dioxygen as the sole oxidant is described, in which the oxygen atom of the furan was from water. The preliminary mechanistic understanding of this transformation was investigated. [ABSTRACT FROM AUTHOR]