Dimethylaminoalkylchalcogenolate complexes of palladium(II): Synthesis, structures, and their catalytic activity in Suzuki C–C cross-coupling reactions

The reaction of [PdCl(E∩N)]n with AgOAc in methanol afforded the corresponding acetato complexes, [Pd(OAc)(E∩N)]n (E∩N/n = ECH2CH2NMe2/3; ECH2CH2CH2NMe2/2 (E = S or Se)). The molecular structures of [Pd(OAc)(ECH2CH2NMe2)]3 were established by single crystal X-ray diffraction analyses. The trimeric structures comprise of three palladium atoms bridged through chalcogen atoms of the chelating chalcogenolate ligand forming a twisted six-membered Pd3E3 ring. The acetato-ligand acts in a monodentate fashion. The catalytic activity of [PdCl(E∩N)]n and [Pd(OAc)(E∩N)]n in Suzuki C–C cross coupling reactions has been investigated. The dimeric acetato complexes showed the best activity in dioxane.

Graphical abstractThe reactions of [PdCl(E∩N)]n with AgOAc yield acetato complexes, [Pd(OAc)(E∩N)]n (E = S or Se; E∩N/n = ECH2CH2NMe2/3; ECH2CH2CH2NMe2/2). The molecular structures of [Pd(OAc)(ECH2CH2NMe2)]3 were established by single crystal X-ray diffraction analyses. The catalytic activity of [PdX(E∩N)]n in Suzuki C–C cross coupling reactions has been investigated.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► N,N′-Dimethylaminoalkylchalcogenolate complexes of palladium have been synthesized. ► The nuclearity of acetato-complexes, [Pd(OAc)(ER)]n is influenced by the nature of R group. ► Pd(II) chalcogenolates are highly active in Suzuki C–C coupling reactions in air. ► Activity of [PdX(E∩N)]n follow the trend: OAc > Cl; S > Se; binuclear > trinuclear.