Application of Cyclic Thiourea as an Efficient Ligand in Palladium-Catalyzed Hiyama Cross-Coupling Reactions

摘要

Cyclic thiourea has been first utilized as an efficient ligand in palladium-catalyzed Hiyama cross-coupling reactions. In the presence of palladium(II) acetate, N,N′-bis(2,5-di-tert-butylphenyl)-N,N′-ethylenethiourea, tetrabutylammonium fluoride, and dioxane, aryl halides (X = I, Br, Cl) underwent smooth cross coupling with trimethoxy(phenyl)silane to afford the corresponding biaryl products in moderate to excellent yields. Furthermore, the thiourea can be recovered by column chromatography and reused with negligible loss in catalytic activity.