Rhodium-Catalyzed Selective Partial Hydrogenation of Alkynes
Rhodium-Catalyzed Selective Partial Hydrogenation of Alkynes
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DOI：
10.1021/acs.organomet.5b00322
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发表时间：
2015-06
期刊：
影响因子：
2.8
通讯作者：
Jingwei Luo;Robin Theron;Laura J. Sewell;T. Hooper;A. Weller;A. Oliver;J. McIndoe
中科院分区：
文献类型：
--
作者：
Jingwei Luo;Robin Theron;Laura J. Sewell;T. Hooper;A. Weller;A. Oliver;J. McIndoe
使用阳离子铑络合物[Rh（PcPr 3）2（η6-PhF）]+[B{3，5-（CF 3）2C 6 H3}4]-（PcPr 3 =三环丙基膦，PhF =氟苯）作为催化剂用于带电荷标记的炔[Ph 3 P（CH 2）4C 2 H]+[PF 6]-的氢化。采用加压进样电喷雾离子化质谱（PSI-ESI-MS）监测反应进程。实验表明，在催化剂存在下，反应为一级反应，在氢气存在下，反应为一级反应，因此在过量氢气条件下，反应为拟零级反应。炔烃加氢比烯烃加氢快40倍。的周转限制步骤，提出了氢的氧化加成的炔（或烯烃）结合的复合物。三乙胺的加入导致速率急剧降低，表明去质子化途径不起作用。
The cationic rhodium complex [Rh(PcPr3)2(η6-PhF)]+[B{3,5-(CF3)2C6H3}4]− (PcPr3 = triscyclopropylphosphine, PhF = fluorobenzene) was used as a catalyst for the hydrogenation of the charge-tagged alkyne [Ph3P(CH2)4C2H]+[PF6]−. Pressurized sample infusion electrospray ionization mass spectrometry (PSI-ESI-MS) was used to monitor reaction progress. Experiments revealed that the reaction is first order in catalyst and first order in hydrogen, so under conditions of excess hydrogen the reaction is pseudo-zero order. Alkyne hydrogenation was 40 times faster than alkene hydrogenation. The turnover-limiting step is proposed to be oxidative addition of hydrogen to the alkyne (or alkene)-bound complex. Addition of triethylamine caused a dramatic reduction in rate, suggesting a deprotonation pathway was not operative.