Synthesis, Reaction and Catalysis of Heterodinuclear Alkyl-and Hydridoplatinum(or palladium) Complexes

（dppe）Hpd-MoCp（CO）_3与丙烯酸乙酯的反应使钼的钼配合物MoHCp（CO）_3立即被还原消除。在此反应中，金属氢化物与丙烯酸乙酯发生进一步的Markovnikov加成反应，生成插入产物Mo[CH（CO_2Et）Me]Cp（CO）_3。在Pd（PPh_3）_4和Pc_1（η^2-CH_2=CHCO_2Et）（dppe）存在下，烯烃顺利插入Mo-H键。室温下，在5mol%Pd（η^2-CH 2 = CHCO 2 Et）（dppe）存在下，钼配合物MoHCp（CO）3在苯中与丙烯酸乙酯反应，在6 h内选择性地定量生成插入产物Mo[CH（CO2 Et）Me]Cp（CO）3。丙烯腈和乙烯也以100%和58%的产率得到相应的插入产物。苯乙烯、丙烯和1-丁烯均未发生插入反应，但1-丁烯发生催化异构化反应，生成顺式和反式2-丁烯的混合物，表明1-丁烯在M-H键上的插入是可逆的。1，2-二取代烯烃如富马酸二甲酯和马来酸二甲酯的插入相对较慢，需要几个小时才能完成，分别得到59%和79%的产率。提出了烯烃通过异双核双金属钯中间体顺式插入Pd-H键的机理。

Reaction of (dppe)HPd-MoCp(CO)_3 with ethyl Reaction of (dppe)HPd-MoCp(CO)_3 with ethyl acrylate caused immediate reductive elimination of the hydridomolybdenum complex MoHCp(CO)_3. In this reaction, further Markovnikov addition of the metal hydride to ethyl acrylate slowly took place to give an insertion product Mo[CH(CO_2Et)Me]Cp(CO)_3. In the presence of Pc1(η^2-CH_2=CHCO_2Et)(dppe) or Pd(PPh_3)_4, smooth catalytic insertion of olefin into Mo-H bond has been achieved. When hydridomolybdenum complex MoHCp(CO)_3 in benzene was treated with ethyl acrylate in the presence 5 mol% of Pd(η^2-CH_2=CHCO_2Et)(dppe) at room temperature, insertion product Mo[CH(CO_2Et)Me]Cp(CO)_3 was selectively formed quantitatively in 6 h. Acrylonitrile and ethylene also gave corresponding insertion products in 100 and 58% yields. No insertion took place for styrene, propylene, or 1-butene, though catalytic isomerization of 1-butene took place to give a mixture of cis- and trans-2-butene, suggesting reversible insertion of 1-butene into M-H bond. Insertion of 1,2-disubstituted olefins such as dimethyl fumarate and dimethyl maleate was relatively slow and it took a few hours to complete, giving 59 and 79% yields, respectively. A mechanism including cis-insertion of olefin into Pd-H bond through heterodinuclear hydridopalladium intermediate is proposed.