Eskedar Tessema1, Vijayanath Elakkat1, Chiao-Fan Chiu2,3, Zong-Lin Tsai1, Ka Long Chan1, Chia-Rui Shen4,5, Han-Chang Su6, Norman Lu1,7. 1. Institute of Organic and Polymeric Materials, National Taipei University of Technology, Taipei 106, Taiwan. 2. Department of Pediatrics, Linkou Medical Center, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan. 3. Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan. 4. Department of Medical Biotechnology and Laboratory Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan. 5. Department of Ophthalmology, Linkou Medical Center, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan. 6. Creditable Service Technology Consultants, New Taipei City 235, Taiwan. 7. Development Center for Smart Textile, National Taipei University of Technology, Taipei 106, Taiwan.
Abstract
The reaction of [PdCl2(CH3CN)2] and bis-4,4'-(RfCH2OCH2)-2,2'-bpy (1a-d), where Rf = n-C11F23 (a), n-C10F21 (b), n-C9F19 (c) and n-C8F17 (d), respectively, in the presence of dichloromethane (CH2Cl2) resulted in the synthesis of Pd complex, [PdCl2[4,4'-bis-(RfCH2OCH2)-2,2'-bpy] (2a-d). The Pd-catalyzed Stille arylations of vinyl tributyltin with aryl halides were selected to demonstrate the feasibility of recycling usage with 2a as the catalyst using NMP (N-methyl-2-pyrrolidone) as the solvent at 120-150 °C. Additionally, recycling and electronic effect studies of 2a-c were also carried out for Suzuki-Miyaura reaction of phenylboronic acid derivatives, 4-X-C6H4-B(OH)2, (X = H or Ph) with aryl halide, 4-Y-C6H4-Z, (Y = CN, H or OCH3; Z = I or Br) in dimethylformamide (DMF) at 135-150 °C. At the end of each cycle, the product mixtures were cooled to lower temperature (e.g., -10 °C), and then catalysts were recovered by decantation with Pd leaching less than 1%. The products were quantified by gas chromatography/mass spectrometry (GC/MS) analysis or by the isolated yield. The complex 2a-catalyzed Stille reaction of aryl iodides with vinyl tributyltin have good recycling results for a total of 8 times, with a high yield within short period of time (1-3 h). Similarly, 2a-c-catalyzed Suzuki-Miyaura reactions also have good recycling results. The electronic effect studies from substituents in both Stille and Suzuki-Miyaura coupling reactions showed that electron withdrawing groups speed up the reaction rate. To our knowledge, this is the first example of recoverable fluorous long-chained Pd-catalyzed Stille reactions under the thermomorphic mode.
The reaction of [PdCl2(CH3CN)2] and bis-4,4'-(RfCn class="Chemical">H2OCH2)-2,2'-bpy (1a-d), where Rf = n-C11F23 (a), n-C10F21 (b), n-C9F19 (c) and n-C8F17 (d), respectively, in the presence of dichloromethane (CH2Cl2) resulted in the synthesis of Pd complex, [PdCl2[4,4'-bis-(RfCH2OCH2)-2,2'-bpy] (2a-d). The Pd-catalyzed Stillearylations of vinyl tributyltin with aryl halides were selected to demonstrate the feasibility of recycling usage with 2a as the catalyst using NMP (N-methyl-2-pyrrolidone) as the solvent at 120-150 °C. Additionally, recycling and electronic effect studies of 2a-c were also carried out for Suzuki-Miyaura reaction of phenylboronic acid derivatives, 4-X-C6H4-B(OH)2, (X = H or Ph) with aryl halide, 4-Y-C6H4-Z, (Y = CN, H or OCH3; Z = I or Br) in dimethylformamide (DMF) at 135-150 °C. At the end of each cycle, the product mixtures were cooled to lower temperature (e.g., -10 °C), and then catalysts were recovered by decantation with Pd leaching less than 1%. The products were quantified by gas chromatography/mass spectrometry (GC/MS) analysis or by the isolated yield. The complex 2a-catalyzed Stille reaction of aryl iodides with vinyl tributyltin have good recycling results for a total of 8 times, with a high yield within short period of time (1-3 h). Similarly, 2a-c-catalyzed Suzuki-Miyaura reactions also have good recycling results. The electronic effect studies from substituents in both Stille and Suzuki-Miyaura coupling reactions showed that electron withdrawing groups speed up the reaction rate. To our knowledge, this is the first example of recoverable fluorous long-chainedPd-catalyzed Stille reactions under the thermomorphic mode.
Authors: Carin C C Johansson Seechurn; Matthew O Kitching; Thomas J Colacot; Victor Snieckus Journal: Angew Chem Int Ed Engl Date: 2012-05-09 Impact factor: 15.336
Authors: K C Nicolaou; N P King; M R Finlay; Y He; F Roschangar; D Vourloumis; H Vallberg; F Sarabia; S Ninkovic; D Hepworth Journal: Bioorg Med Chem Date: 1999-05 Impact factor: 3.641