- About this Journal
- Abstracting and Indexing
- Aims and Scope
- Article Processing Charges
- Articles in Press
- Author Guidelines
- Bibliographic Information
- Citations to this Journal
- Contact Information
- Editorial Board
- Editorial Workflow
- Free eTOC Alerts
- Publication Ethics
- Submit a Manuscript
- Subscription Information
- Table of Contents
ISRN Organic Chemistry
Volume 2012 (2012), Article ID 814247, 4 pages
Catalyzed C–C Coupling of Aryl Iodides and Boronic Acids
Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
Received 28 August 2012; Accepted 14 September 2012
Academic Editors: S. Bellemin-Laponnaz, T. C. Dinadayalane, L. Minuti, and T. Ogiku
Copyright © 2012 Payal Malik and Debashis Chakraborty. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
An efficient La2O3-catalyzed new route for the carbon-carbon bond formation in particular, symmetrical and unsymmetrical biphenyls has been developed, which proceeds through carbon-carbon coupling reaction of aryl iodides with boronic acids. The reaction provided the desired products in moderate-to-good yields with a wide range of functional group tolerance.
The formation of new carbon-carbon bonds is of central importance in organic and medicinal chemistry [1, 2]. The development of new methods for carbon-carbon bond formation is a well-growing area in organic chemistry . In the past decades, tremendous efforts have been devoted into the transition-metal catalyzed cross-coupling reactions . The transition metals have played an important role in organic chemistry and this has led to the development of a large number of transition metal-catalyzed reactions for the formation of C–C and carbon-heteroatom bonds in organic synthesis [5, 6]. In the literature, a variety of nontransition and transition metals like palladium [7–9], copper [10, 11], iron , nickel [13, 14], cobalt , zinc , indium , solid supported catalyst , and metal nanoparticle  have been used for the coupling reactions. In fact palladium-catalyzed Suzuki-type cross-coupling reactions are very well explored and frequently used in organic synthesis and medicinal chemistry . Organoborane and boronic acids have been utilised as arylating agent for the C–C bond formation [7–15].
Metal oxides represent one of the most important and widely used solid catalysts, either as active phases or as supports. The metal oxides are the largest family of catalysts in heterogeneous catalysis due to the acid-base and redox properties [20–23]. The outer electron configuration of the transition and noble group metals made them the most frequently used catalysts . These metal oxides have been proved as efficient catalysts for the coupling reaction. Hell and coworkers reported copper-free Sonogashira reaction of alkynes and aryl halides by using Pd/MgLa mixed oxide . Herein, we have developed a La2O3 catalyzed C–C coupling by using aryl halide and boronic acids.
2. Experimental Section
2.1. General Considerations
All the substrates used in this study were purchased from Aldrich and used as received. All the solvents were purchased from Ranchem, India and purified using standard methods. The products are characterized by recording 1H, 13C NMR, and ESI-MS by using Bruker Avance 400 MHz instrument and JEOL JMS GC-mate II instrument.
2.2. Typical Procedure for C–C Coupling Reaction
To a stirred solution of boronic acid (1 mmol) and La2O3 (10 mol%) in DMSO (3 mL) was added aryl iodides (1 mmol) followed by trans-1,2-diaminocyclohexane (10 mol%) and KO-t-Bu (2 equiv.). The reaction mixture was heated to 150°C and the progress of reaction was monitored by TLC. After completion, the reaction mixture was washed with EtOAc-H2O and the organic phase was separated and dried over Na2SO4. The EtOAc was evaporated, and the further purification was done by using column chromatography.
3. Result and Discussion
To optimize the reaction conditions, different bases and solvents were screened in the presence of La2O3 as catalyst for the C–C coupling reactions. For the initial studies, we chose phenyl iodide and phenyl boronic acid as model substrates and various ligands and bases were screened (Table 1). The results revealed that the trans-1,2-diamino cyclohexane (L2) was the best ligand for the coupling reaction. N,N′-dimethylethane-1,2-diamine (L4) was proved to be an effective ligand in the coupling reaction; in fact, the reaction took a little longer time to complete as compared to the L2 (entry 3 versus entry 16). On the basis of base optimization results, KO-t-Bu was found to be the best base among the rest of the bases which have been used for optimization (Table 1, entry 3). Among the different solvents, DMSO gave the best results (Table 1, entry 3). On the ground of optimization results, we concluded that phenyl iodide and phenyl boronic acid in combination of La2O3 (10 mol%), KO-t-Bu (2 equiv.), trans-1,2-diaminocyclohexane (L2) (10 mol%), and DMSO as solvent at 150°C is the most efficacious reaction condition.
After optimizing the reaction conditions, we have explored the substrate scope by carrying out the reaction with various aryl halides and the results are illustrated in Table 2.
Alkyl substituted halide substrates (Table 2, entries 2–5) gave good yield as shown in Table 2. In case of phenyl boronic acid and phenyl iodide coupling reaction, the observed yield was good, since the homocoupled and coupled product is biphenyl. Electron donating substrates (Table 1, entries 2–5) provided biaryl in shorter reaction time as compared to the electron withdrawing substrates (Table 2, entries 2–5 versus entries 6–8). As a matter of fact, a small amount of homocoupled products were observed in the reaction mixtures. There is a report which discusses the formation of homo-coupled product from boronic acids under similar conditions . To confirm this, we have performed the reaction without phenyl iodide and observed 5–15% of the homo-coupled product in the reaction mixture.
In summary, we have developed an efficient La2O3-catalyzed new route for the carbon-carbon bond formation. The developed catalytic system shows the wide range substrate applicability and functional group tolerance. A small amount of homo-coupled aryls as side product was observed.
- P.-L. Boudreault, S. Cardinal, and N. Voyer, “Efficient preparation of 2-aminomethylbiphenyls via suzuki-miyaura reactions,” Synlett, no. 16, pp. 2449–2452, 2010.
- A. Collier and G. K. Wagner, “A fast synthetic route to GDP-sugars modified at the nucleobase,” Chemical Communications, no. 2, pp. 178–180, 2008.
- A. Suzuki, “Carbon-carbon bonding made easy,” Chemical Communications, no. 38, pp. 4759–4763, 2005.
- A. de Meijere and F. Diederich, Eds., Metal-Catalyzed Cross-Coupling Reactions, Wiley-VCH, Weinheim, Germany, 2nd edition, 2004.
- J. Tsuji, Transition Metal Reagents and Catalysts: Innovations in Organic Synthesis, John Wiley & Sons, New York, NY, USA, 2000.
- M. Beller and C. Bolm, Transition Metals for Organic Synthesis, Wiley-VCH, Weinheim, Germany, 2nd edition, 2004.
- F. Mo, D. Qiu, Y. Jiang, Y. Zhang, and J. Wang, “A base-free, one-pot diazotization/cross-coupling of anilines with arylboronic acids,” Tetrahedron Letters, vol. 52, no. 4, pp. 518–522, 2011.
- T. Kinzel, Y. Zhang, and S. L. Buchwald, “A new palladium precatalyst allows for the fast Suzuki-Miyaura coupling reactions of unstable polyfluorophenyl and 2-heteroaryl boronic acids,” Journal of the American Chemical Society, vol. 132, no. 40, pp. 14073–14075, 2010.
- S. Yahiaoui, A. Fardost, A. Trejos, and M. Larhed, “Chelation-mediated palladium(II)-catalyzed domino heck-mizoroki/suzuki-miyaura reactions using arylboronic acids: increasing scope and mechanistic understanding,” Journal of Organic Chemistry, vol. 76, no. 8, pp. 2433–2438, 2011.
- M. L. Kantam, G. T. Venkanna, C. Sridhar, B. Sreedhar, and B. M. Choudary, “An efficient base-free N-arylation of imidazoles and amines with arylboronic acids using copper-exchanged fluorapatite,” Journal of Organic Chemistry, vol. 71, no. 25, pp. 9522–9524, 2006.
- J. Mao, J. Guo, F. Fang, and S. J. Ji, “Highly efficient copper(0)-catalyzed Suzuki-Miyaura cross-coupling reactions in reusable PEG-400,” Tetrahedron, vol. 64, no. 18, pp. 3905–3911, 2008.
- A. Correa, M. Carril, and C. Bolm, “Iron-catalyzed S-arylation of thiols with aryl iodides,” Angewandte Chemie, vol. 47, no. 15, pp. 2880–2883, 2008.
- Z. Lu and G. C. Fu, “Alkyl-alkyl Suzuki cross-coupling of unactivated secondary alkyl chlorides,” Angewandte Chemie, vol. 49, no. 37, pp. 6676–6678, 2010.
- M. Baghbanzadeh, C. Pilger, and C. O. Kappe, “Rapid nickel-catalyzed suzuki-miyaura cross-couplings of aryl carbamates and sulfamates utilizing microwave heating,” Journal of Organic Chemistry, vol. 76, no. 5, pp. 1507–1510, 2011.
- Y.-C. Wong, T. T. Jayanth, and C. H. Cheng, “Cobalt-catalyzed aryl-sulfur bond formation,” Organic Letters, vol. 8, no. 24, pp. 5613–5616, 2006.
- C. C. Eichman and J. P. Stambuli, “Zinc-mediated palladium-catalyzed formation of carbon-sulfur bonds,” Journal of Organic Chemistry, vol. 74, no. 10, pp. 4005–4008, 2009.
- V. P. Reddy, K. Swapna, A. V. Kumar, and K. R. Rao, “Indium-catalyzed C–S cross-coupling of aryl halides with thiols,” Journal of Organic Chemistry, vol. 74, no. 8, pp. 3189–3191, 2009.
- H. Zhao, J. Peng, R. Xiao, and M. Cai, “A simple, efficient and recyclable phosphine-free catalytic system for Suzuki-Miyaura reaction of aryl bromides,” Journal of Molecular Catalysis A, vol. 337, no. 1-2, pp. 56–60, 2011.
- O. Metin, F. Durap, M. Aydemir, and S. Ozkar, “Palladium(0) nanoclusters stabilized by poly(4-styrenesulfonic acid-co-maleic acid) as an effective catalyst for Suzuki-Miyaura cross-coupling reactions in water,” Journal of Molecular Catalysis A, vol. 337, no. 1-2, pp. 39–44, 2011.
- H. H. Kung, “Transition metal oxides: surface chemistry and catalysis,” in Studies in Surface Science and Catalysis, vol. 45, pp. 1–277, Elsevier, Amsterdam, The Netherlands, 1989.
- V. E. Henrich and P. A. Cox, The Surface Science of Metal Oxides, Cambridge University Press, Cambridge, UK, 1994.
- C. Noguera, Physics and Chemistry at Oxide Surface, Cambridge University Press, Cambridge, UK, 1996.
- S. U. Sonavane, M. B. Gawande, S. S. Deshpande, A. Venkataraman, and R. V. Jayaram, “Chemoselective transfer hydrogenation reactions over nanosized γ-Fe2O3 catalyst prepared by novel combustion route,” Catalysis Communications, vol. 8, no. 11, pp. 1803–1806, 2007.
- G. C. Bond, Catalysis by Metals, Academic Press, New York, NY, USA, 1962.
- A. Cwik, Z. Hell, and F. Figueras, “A copper-free Sonogashira reaction using a Pd/MgLa mixed oxide,” Tetrahedron Letters, vol. 47, no. 18, pp. 3023–3026, 2006.
- R. S. Varma and K. P. Naicker, “Synthesis of allylbenzenes: by cross-coupling of allyl bromide with arylboronic acids using a palladium chloride and tetraphenylphosphonium bromide intercalated clay catalyst,” Green Chemistry, vol. 1, no. 5, pp. 247–249, 1999.