Xylyl isocyanide platinum and palladium complexes

Multiple Roles of Isocyanides in Palladium‐Catalyzed Imidoylative Couplings: A Mechanistic Study

“…The exact nature of RNC‐ligated Pd 0 in solution in the presence of excess isocyanide, which is relevant for catalytic reactions, has not been investigated experimentally. Isolated complexes of stoichiometry [Pd(CNR) 2 ] have long been known . Usually, they show a trimeric structure in the solid state (except for the case of extremely hindered isocyanides, which give rise to monomers), but molecular weight determination in solution has not been conclusive .…”

“…Isolated complexes of stoichiometry [Pd(CNR) 2 ] have long been known . Usually, they show a trimeric structure in the solid state (except for the case of extremely hindered isocyanides, which give rise to monomers), but molecular weight determination in solution has not been conclusive . Moreover, formation of complexes featuring more than two isocyanide ligands is conceivable in the presence of excess isocyanide.…”

Hexapalladium cluster: Unique cluster construction reaction of cyclic Pd3(CNC6H3Me2-2,6)6 and linear [Pd3(CNC6H3Me2-2,6)8]2+

“…Dehydrated acetone was degassed by trap-to-trap distillation before use. Complexes Pd 3 -(CNXyl) 6 (1) and [Pd 2 (CNXyl) 6 ][PF 6 ] 2 (2) were prepared according to the literature procedures [10,11].…”

“…It is well known that one metal fragment of d 10 transition metals can be inserted into the M(I)-M(I) bond of dinuclear complexes (M = Pt and Rh) to form heterotrinuclear A-frame complexes: [Pt 2 Pd(l-dpmp) 2 -(CNMes) 2 ] 2+ [7], [Pt 2 (l-HgCl 2 )Cl 2 (l-dppm) 2 ] [8], and [(CpRh) 2 (l-AuPPh 3 )(l-CO)(l-dppm) 2 ] + [9] have been synthesized by the insertion reactions of Pd(CNMes) 2 , HgCl 2 , and [AuPPh 3 ] + into the corresponding Pt 2 and Rh 2 complexes, respectively. In the case of homoleptic palladium isocyanide complexes, although many di-, tri-, and multinuclear complexes with isocyanide ligands have been prepared by electrochemical reaction of metal ions in different formal oxidation states [10][11][12][13][14][15][16], such an insertion reaction of a 'Pd 0 (CNMe) 2 ' fragment into a dicationic dipalladium complex [Pd 2 (CNMe) 6 ] 2+ with d 9 configuration has been successfully applied to yield the linear tripalladium complex [Pd 3 (CNMe) 8 [13g]. It was our surprise that there was no insertion reaction of a ''Pd 0 L 2 '' species into metal cluster compounds with higher nuclearity such as [Pd 3 L 8 ] 2+ , except for a linear tetrapalladium complex [Pd 4 (l-g 3 :g 2 :g 2 :g 3 -1,8-diphenylocta-1,3,5,7-tetraene) 2 ] 2+ , which was a product of the formal consecutive insertions of two Pd(0) to the Pd(I)-Pd(I) bond of the starting complex Pd 2 ðMeCNÞ 2þ 6 in the presence of tetraene ligands [17].…”

“…We have been intrigued by the insertion reaction of metal fragments into the metal-metal bonded clusters as an ideal synthetic method for constructing metal-metal bonded polynuclear complexes [6]. It is well known that one metal fragment of d 10 transition metals can be inserted into the M(I)-M(I) bond of dinuclear complexes (M = Pt and Rh) to form heterotrinuclear A-frame complexes: [Pt 2 Pd(l-dpmp) 2 -(CNMes) 2 ] 2+ [7], [Pt 2 (l-HgCl 2 )Cl 2 (l-dppm) 2 ] [8], and [(CpRh) 2 (l-AuPPh 3 )(l-CO)(l-dppm) 2 ] + [9] have been synthesized by the insertion reactions of Pd(CNMes) 2 , HgCl 2 , and [AuPPh 3 ] + into the corresponding Pt 2 and Rh 2 complexes, respectively. In the case of homoleptic palladium isocyanide complexes, although many di-, tri-, and multinuclear complexes with isocyanide ligands have been prepared by electrochemical reaction of metal ions in different formal oxidation states [10][11][12][13][14][15][16], such an insertion reaction of a 'Pd 0 (CNMe) 2 ' fragment into a dicationic dipalladium complex [Pd 2 (CNMe) 6 ] 2+ with d 9 configuration has been successfully applied to yield the linear tripalladium complex [Pd 3 (CNMe) 8 [13g].…”