N-Heterocyclic Carbene/Pd(OAc)2 Catalyzed Heck Coupling in Aqueous Medium

Öz

In this study, novel 4-phenoxybutyl-substituted benzimidazolium salts as N-heterocyclic carbene (NHC) ligands were successfully synthesized and their structures characterized by 1H NMR, 13C NMR, FT-IR, and elemental analysis techniques. The in situ formed catalytic system using the NHC ligands and Pd(OAc)2 was used in the Heck coupling reactions between aryl bromides and strene with potassium carbonate in water/DMF mixture. The corresponding coupling products were obtained in high yields.

Anahtar Kelimeler

• N-Heterocyclic carbene,C-C cross-coupling reactions,Heck coupling

Sulu Ortamda N-Heterosiklik Karben/Pd(OAc)2 Katalizli Heck C-C Eşleşmesi

Öz

Bu çalışmada, N-heterosiklik karben (NHC) ligandı olarak yeni 4-fenoksibütil sübstitüyentli benzimidazolyum tuzları sentezlendi ve yapıları 1H NMR, 13C NMR, FT-IR ve element analizi yöntemleri ile karakterize edildi. Pd(OAc)2 ve NHC ligandları kullanılarak in situ oluşturulan katalitik sistem, su/DMF karışımında, potasyum karbonat varlığında stiren ve aril bromürlerin Heck eşleşme tepkimelerinde kullanıldı. Eşleşme ürünleri yüksek dönüşüm oranlarında elde edildi.

Anahtar Kelimeler

• N-Heterosiklik karben,C-C çapraz eşleşme tepkimeleri,C-C çapraz eşleşme tepkimeleri,Heck eşleşmesi

Kaynakça

1. Bazinet P, Ong TG, O’Brien JS, Lavoie N, Bell E, Yap GPA, Korobkov I, Richerson DS, 2007. Design of Sterically Demanding, Electron-Rich Carbene Ligans With The Perimidine. Scaffold Organometallics, 26: 2885-2895.
2. Bazinet P, Yap GPA, Richeson DS, 2003. Constructing a Stable Carbene with a Novel Topology and Electronic Framework. Journal of American Chemical Society, 125: 13314-13315.
3. Beller M, Wu XF, Anbarasan P, Neumann H, 2010. From Noble Metal to Nobel Prize: Palladium-Catalyzed Coupling Reactions as Key Methods in Organic Synthesis. Angewandte Chemie International Edition, 49: 9047-9050.
4. Borguet Y, Zaragoza G, Demonceaua A, Delaude L, 2013. Assessing the ligand properties of 1,3-dimesitylbenzimidazol-2-ylidene in ruthenium-catalyzed olefin metathesis. Dalton Transaction, 42: 7287-7296.
5. Demir S, Özdemir İ, Çetinkaya B, Arslan H, VanDerveer D, 2011. Synthesis and characterization of bidentate NHC-Pd complexes and their role in amination reactions. Polyhedron, 30: 195-200.
6. Demir S, Zengin R, Özdemir İ, 2012. Potential N-Heterocyclic Carbene Precursors in the Palladium-Catalyzed Heck Reaction. Heteroatom Chemistry, 24: 77-83.
7. Hadei N, Kantchev EAB, O'Brien CJ, Organ MG, 2005. Electronic Nature of N-Heterocyclic Carbene Ligands:  Effect on the Suzuki Reaction. Organic Letters, 7-10: 1991-1994.
8. Heck RF, Nolley JP, 1972. Palladium-Catalyzed Vinylic Hydrogen Substitution Reactions with Aryl, Benzyl, and Styryl Halides. Journal of Organic Chemistry, 37: 2320-2322.

9. Herrmann WA, 2002. N-Heterocyclic Carbenes: A New Concept in Organometallic Catalysis. Angewandte Chemie International Edition, 41: 1290-1309.
10. Joo F, 2002. Aqueous Biphasic Hydrogenations. Accounts of Chemical Research, 35: 738-745.
11. Kaloğlu M, Kaloğlu N, Özdemir İ, Günal S, Özdemir İ, 2016. Novel benzimidazol-2-ylidene carbene precursors and their silver(I) complexes: Potential antimicrobial agents. Bioorganic & Medicinal Chemistry, 24: 3649-3656.
12. Kaloğlu M, Özdemir İ, 2018. Palladium(II)/N-Heterocyclic Carbene Complexes:Efficient Catalysts for the Direct C-H Bond Arylation of Furans with Aryl Halides. Applied Organometallic Chemistry, DOI: 10.1002/aoc.4399.
13. Kaloğlu M, Özdemir İ, Dorcet V, Bruneau C, Doucet H, 2017. PEPPSI-Type Palladium–NHC Complexes: Synthesis, Characterization, and Catalytic Activity in the Direct C5-Arylation of 2-Substituted Thiophene Derivatives with Aryl Halides. European Journal of Inorganic Chemistry, 1382-1391.
14. McGuiness DS, Saendig N, Yates BF, Cavell KJ, 2001. Kinetic and Density Functional Studies on Alkyl-Carbene Elimination from PdII Heterocylic Carbene Complexes:  A New Type of Reductive Elimination with Clear Implications for Catalysis. Journal of American Chemical Society, 123: 4029-4040.
15. Mecking S, Held A, Bauers FM, 2002. Aqueous Catalytic Polymerization of Olefins. Angewandte Chemie International Edition, 41: 544-561.
16. Paradiso V, Costabile C, Grisi F, 2016. NHC Backbone Configuration in Ruthenium-Catalyzed Olefin Metathesis. Molecules, 21: 117.
17. Peris E, Crabtree RH, 2004. Recent homogeneous catalytic applications of chelate and pincer N- heterocyclic carbenes. Coordination Chemistry Reviews, 248: 2239-2246.
18. Sustainable Chemistry Strategic Research Agenda, 2013. Suscem.org http://www.suschem.org/upl/3/default/doc/Suschem_SRA_final.pdf. The Nobel Prize in Chemistry, 2010. Press Release, Nobelprize.org http://www.nobelprize.org/nobel_prizes/chemistry/laureates/2010/press.html. (E.T: 06.10.2010).
19. Titcomb LR, Caddick S, Cloke FGN, Wilson DJ, McKerrecher D, 2001. Unexpected reactivity of two-coordinate palladium-carbene complexes; synthetic and catalytic implications. Chemical Communications, 1388-1389.
20. Trost BM, Verhoeven TR, 1982. Organopalladium Compounds in Organic Synthesis and in Catalysis. In Comprehensive Organometallic Chemistry. Pergamon: Oxford, 799-938.
21. Yiğit B, Yiğit M, Özdemir İ, Çetinkaya E, 2010. Picolyl Substituted N-Heterocyclic Carbene Palladium Catalyzed Heck Reactions. Turkish Journal of Chemistry, 34: 327-334.