Takuya Kochi

Synthesis of anionic methylpalladium complexes with phosphine–sulfonate ligands and their activities for olefin polymerization

Reaction of diarylphosphinobenzene-2-sulfonic acids with tertially amines, followed by addition of [PdMeCl(cod)], provided anionic methylpalladium(II) complexes with bidentate phosphine-sulfonate ligands, which show high activity for copolymerization of ethylene with methyl acrylate.

Synthesis and structures of heterobimetallic Ir2M (MPd, Pt) sulfido clusters and their catalytic activity for regioselective addition of alcohols to internal 1-aryl-1-alkynes

The heterobimetallic trinuclear sulfido clusters [(Cp*Ir)2(μ3-S)2MCl2] (M=Pd (3), Pt (4); Cp*=η5-C5Me5) were synthesized from the dinuclear hydrogensulfido complex [Cp*IrCl(μ-SH)2IrCp*Cl] (2) and [MCl2(COD)] (COD=cycloocta-1,5-diene), while the reaction of 2 with [Pd(PPh3)4] afforded the cationic trinuclear cluster [(Cp*Ir)2(μ3-S)2PdCl(PPh3)]Cl (5). Clusters 3 and 4 reacted with PPh3 to give a series of mono and dicationic clusters including 5, while the dicationic clusters [(Cp*Ir)2(μ3-S)2M(dppe)][BPh4]2 (M=Pd (9), Pt (10); dppe=Ph2PCH2CH2PPh2) were obtained by the reaction with dppe followed by anion metathesis. The molecular structures of 5·CH2Cl2, 9·CH3COCH3, and 10·CH3COCH3 were determined by X-ray crystallography. Clusters 3 and 4 were found to catalyze the addition of alcohols to alkynes to give the corresponding acetals. Internal 1-aryl-1-alkynes were transformed by cluster 3 into the corresponding 2,2-dialkoxy-1-arylalkanes with high regioselectivity up to 99:1, while cluster 4 was a much less regioselective catalyst.

SYNTHESIS AND REACTIVITIES OF IR2RU HETEROBIMETALLIC SULFIDO CLUSTERS DERIVED FROM A HYDROGENSULFIDO-BRIDGED DIIRIDIUM COMPLEX

The hydrogensulfido-bridged diiridium complex [ClCp*Ir(µ-SH)2IrCp*Cl] reacted with [RuH2(PPh3)4] to give a mixed-metal trinuclear cluster with an Ir2Ru(µ3-S)2 core [(Cp*Ir)2(µ3-S)2RuCl2(PPh3)] 2, which was further converted into the cationic diphosphine derivatives [(Cp*Ir)2(µ3-S)2RuCl(L)]Cl (Lxa0=xa0dppexa0=xa0Ph2PCH2CH2PPh2 3 or depexa0=xa0Et2PCH2CH2PEt2 4). The reaction of cluster 3 with Me2CuLi followed by anion metathesis with KPF6 afforded the cationic methyl cluster [(Cp*Ir)2(µ3-S)2RuMe(dppe)][PF6] 5 in good yield, while treatment of 3 with CHCl2Li led to selective formation of [(Cp*Ir){(η4-C5Me5CHCl2)Ir}(µ3-S)2RuCl(dppe)] 6, in which one of the Cp* ligands was alkylated by CHCl2Li to form an η4-diene. Clusters 3 and 4 were also transformed into the dihydrido clusters [(Cp*Ir)2(µ3-S)2(µ-H)2Ru(L)] (Lxa0=xa0dppe 7 or depe 8) by the reaction with NaBH4. On the other hand, cluster 2 was converted into the carbonyl cluster [(Cp*Ir)2(µ3-S)2RuCl(CO)(PPh3)]Cl 9, the isocyanide clusters [(Cp*Ir)2(µ3-S)2RuCl(CNXy)(PPh3)]Cl 10 (Xyxa0=xa02,6-C6H3Me2) and [(Cp*Ir)2(µ3-S)2Ru(CNXy)2(PPh3)][BPh4]2 11 and the co-ordinatively unsaturated thiolato clusters [(Cp*Ir)2(µ3-S)2Ru(SAr)2] (Arxa0=xa02,4,6-C6H2Pri3 12 or Xy 13) on treatment with CO, XyNC and LiSAr, respectively. The molecular structures of [(Cp*Ir)2(µ3-S)2RuCl(depe)][BPh4] 4′, 5·CH2Cl2, 6, 7 and 12·2C6H6 were established by X-ray diffraction studies.