Treatment of Pt(PPh₃)₄ or Pt(iMes)₂ (iMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene) with iminium chloride salts in THF produced [Pt(II)Cl(=CHNR₂)]⁺ complexes. Complex [PtCl(PPh₃)₂(=CHNMe₂)]BPh₄ (2.1) can be converted to [PtCl(dppf)(=CHNMe₂)]BPh₄ (dppf = 1,1’-ferrocenediyl-bis( diphenylphosphine)) (2.3) by the treatment with dppf. Reactivities of the platinum carbene complexes (2.1, 2.2 and 2.3) with different reactants were tested but the targeting carbyne complexes could not be obtained.

Reaction of a pyrrole-based (PNP)^-Li⁺(THF) pincer ligand ([PNP]^- = [2,5-(Ph₂PCH₂)₂C₄H₂N]^-) with RhCl(PPh₃)₃ and RhCl(CO)(PPh₃)₂ in toluene produced the rhodium(I) complexes, Rh(PNP)(PPh3) (3.3) and Rh(PNP)(CO) (3.4) respectively, which have been characterized by ¹H and ³¹P{¹H} NMR spe...[ Read more ]

Treatment of Pt(PPh₃)₄ or Pt(iMes)₂ (iMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene) with iminium chloride salts in THF produced [Pt(II)Cl(=CHNR₂)]⁺ complexes. Complex [PtCl(PPh₃)₂(=CHNMe₂)]BPh₄ (2.1) can be converted to [PtCl(dppf)(=CHNMe₂)]BPh₄ (dppf = 1,1’-ferrocenediyl-bis( diphenylphosphine)) (2.3) by the treatment with dppf. Reactivities of the platinum carbene complexes (2.1, 2.2 and 2.3) with different reactants were tested but the targeting carbyne complexes could not be obtained.

Reaction of a pyrrole-based (PNP)^-Li⁺(THF) pincer ligand ([PNP]^- = [2,5-(Ph₂PCH₂)₂C₄H₂N]^-) with RhCl(PPh₃)₃ and RhCl(CO)(PPh₃)₂ in toluene produced the rhodium(I) complexes, Rh(PNP)(PPh3) (3.3) and Rh(PNP)(CO) (3.4) respectively, which have been characterized by ¹H and ³¹P{¹H} NMR spectroscopies. Rh(PNP)(PPh₃) (3.3) reacted with iminium chloride salts to give [RhCl(PNP)(PPh₃)(=CHNR₂)]⁺ (3.5 and 3.6). Rh(PNP)(PPh₃) (3.3) also reacted with phenylacetylene to form a vinylidene complex (3.8) in equilibrium. No reactions were observed between Rh(PNP)(PPh₃) (3.3) and alcohols, propylene oxide or hydrogen gas.

New phosphine ligands (2-hydroxyphenyl)bis(4-methoxyphenyl)phosphine (4.4) and (2-hydroxyphenyl)bis(4-(trifluoromethyl)phenyl)phosphine (4.7) were synthesized. Treatment of ReCl₂(≡CBn)(PMePh₂)₃ with phosphine 4.4 and 4.7 in toluene produced Re(≡CBn)((p-OMe)PO)₂(PMePh₂) (4.8) and Re(≡CBn)((p-CF₃)PO)₂(PMePh₂) (4.9). Catalytic activities of Re(≡CBn)((p-OMe)PO)₂(PMePh₂) and Re(≡CBn)((p-CF₃)PO)₂(PMePh₂) for metathesis of internal alkynes were tested.