Synthesis, Characterization and Catalytic Application of Aminodipyridylphosphine Oxide Copper(II) Complex and Its Supported Form on Gold Nanoparticles

• Main Authors: GHIA-JUNG TSAO, 曹嘉榮
• Other Authors: Shuchun Joyce Yu
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/55766063507215701915

碩士 === 國立中正大學 === 化學所 === 98 === We have successfully synthesized copper(II) aminodipyridylphosphine oxide complex [HO(CH2)11N(H)P(O)(2-py)2]Cu(OTf)2 (3) and gold nanoparticles-supported catalyst Au NPs-S(CH2)11N(H)P(O)(2-py)2Cu(OTf)2 (10) in quantitative yields. The complex 3 was synthesized by direct reaction of Cu(CF3SO3)2 and HO(CH2)11N(H)P(O)(2-py)2 (2) in a mixed solvent system of CH2Cl2 and CH3CN (v/v = 10:1) at 25 oC for 12 hours. The resulting solution was concentrated and a portion of ether acting as diffusion solvent was added at 0 oC to give [HO(CH2)11N(H)P(O)(2-py)2]Cu(OTf)2 (3) as green precipitates. The moisture- and air-stable green powdered products were obtained by decanting off the supernatant followed by drying under vacuum. The complex 3 was paramagnetic and could be characterized by IR, FAB-MS, EPR, XPS, EA and X-ray crystallography. The octanethiolate protected gold nanoparticles (Au NPs), RS-Au (8, R = C8H17), were functionalized with HS(CH2)11N(H)P(O)(2-py)2 (7) by the ligand-exchange method to give mixed thiolates-covered Au NPs, RS-Au-L (9), where L = HS(CH2)11NHP(O)(2-py)2. Afterward, a mixture of Cu(CF3SO3)2 and 9 in a mixed solvent system of CH2Cl2 and CH3CN (v/v = 5:1) was allowed to stir at 25 oC for 16 hours to give the hybrid catalyst RS-Au-L-Cu(OTf)2 (10). The Au NPs 10 was also paramagnetic and was characterized by IR, UV, EPR, XPS, TEM and AA spectroscopies. The complex 3 and Au NPs 10 were proved to be highly effective catalysts for a series of annulation reactions of para-substituted phenols and/or naphthols with 1,3-dienes. With a catalyst loading of 5 mol% of 3 or 10, the annulation reactions could be completed in 18 hours in CH2Cl2 at 50 oC to give desired products in 60-95% yields. We also found that the reactivity phenols and/or naphthols with electron-rich substituents provided better reactivity in the following order: R = p-(CH3)3CH > p-OCH3 > p-CH3 > H. In contrast, when electron-withdrawing substituents such as Br- and I- were present the reactivity decreased as expected. In addition, by using (bmim)PF6 (bmim = 1-butyl-3-methylimidazolium) as the green solvent, 3 or 10-catalyzed annulation reactions of para-substituted phenols and/or naphthols with 1,3-dienes could be further accelerated under 600 W microwave irradiation conditions to give desired products in 85-94% yields in just 50 seconds. In the presence of our target hybrid catalyst 10 (20 mol%), the annulation reactions of p-cresol with isoprene were carried out at 50 oC and in a mixed solvent system of CH2Cl2 and CH3CN (v/v = 10:1) to give the corresponding products with >95% yield in 3 hours. The catalyst 10 could be quantitatively recovered and effectively recycled more than 14 cycles without any significant loss of activity. However, the recycling of catalyst 3 showed that the yield dropped from 99% in the 1st cycle to 46% in the 3rd cycle.