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首页> 外文期刊>Chemistry: A European journal >Homogeneous Catalysts Supported on Soluble Polymers: Biphasic Sonogashira Coupling of Aryl Halides and Acetylenes Using MeOPEG-Bound Phosphine-Palladium Catalysts for Efficient Catalyst Recycling
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Homogeneous Catalysts Supported on Soluble Polymers: Biphasic Sonogashira Coupling of Aryl Halides and Acetylenes Using MeOPEG-Bound Phosphine-Palladium Catalysts for Efficient Catalyst Recycling

机译：均相催化剂负载在可溶性聚合物上：使用MeOPEG结合的膦-钯催化剂高效催化回收芳基卤化物和乙炔的双相Sonogashira偶联

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摘要

The Sonogashira coupling of various aryl bromides and iodides with different acetlylenes was studied under biphasic conditions with soluble, polymer-modified catalysts to allow the efficient recycling of the homogeneous catalyst. For this purpose, several sterically demanding and electron-rich phosphines of the type R_PPR_2 were synthesised. The are covalently linked to a monomethyl polyethylene glycol ether with a mass of 2000 Dalton (R_P=MeOPEG_2000) R_PPR_2: -PR_2=-CH_2C_6H_4CH_2P(1-Ad)_2, -C_6H_4-P-(1-Ad)_2, -C_6H_4-PPh_2. To couple aryl iodides and acetylenes, the catalyst [(MeCN)_2PdCl_2]/2R_P-C_6H_4-PPh_2 was used in CH_3CN/Et_3N-heptane (5/25). The combined yields of coupling product over five reaction cycles are vbetween 80-95%. There is no apparent leaching of the catalyst into n-heptane, as evidenced by ~1H NMR spectroscopy. The new catalyst [(MeCN)_2PdCl_2(1-Ad)_2 linked to the polymer was usedto couple aryl bromides and acetylenes in DMSO or DMSO-heptane at 60 deg C with 0.5 mol% Na_2[PdCl_4], 1 mol% R_PPR_2 and 0.33 mol% CuI. The combined yield of coupling products over five cycles is always greater than 90%, except for sterically hindered arlyst indicates only a small decrease in activity over five cycles. Leaching of the catalyst into the product containing n-heptane solution could not be detected by means of ~1H NMR and TXRF; this is indicative of >99.995% catalyst retention in the DMSO solvent.
机译：在双相条件下，使用可溶性，聚合物改性的催化剂研究了各种芳基溴化物和碘化物与不同的乙炔的Sonogashira偶联，以有效地回收均相催化剂。为此目的，合成了几种R_PPR_2类型的空间需求的和富电子的膦。它们与质量为2000道尔顿的单甲基聚乙二醇醚共价连接（R_P = MeOPEG_2000）R_PPR_2：-PR_2 = -CH_2C_6H_4CH_2P（1-Ad）_2，-C_6H_4-P-（1-Ad）_2，-C_6H_4- PPh_2。为了偶联芳基碘化物和乙炔，在CH_3CN / Et_3N /正庚烷（5/25）中使用催化剂[（MeCN）_2PdCl_2] / 2R_P-C_6H_4-PPh_2。在五个反应周期内偶联产物的总产率在80-95％之间。如〜1H NMR光谱所证明的，没有明显的催化剂浸出到正庚烷中。使用新的与聚合物连接的催化剂[（MeCN）_2PdCl_2（1-Ad）_2）在DMSO或DMSO /正庚烷中于60℃，0.5 mol％Na_2 [PdCl_4]，1 mol％R_PPR_2偶联芳基溴和乙炔。和0.33mol％的CuI。在五个周期内偶合产物的总收率始终大于90％，除了空间受阻的芳烃表明在五个周期内活性只有很小的下降。 〜1H NMR和TXRF检测不到催化剂浸入含正庚烷溶液的产物。这表明催化剂在DMSO溶剂中的保留率> 99.995％。

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