Namık ÖZDEMİR, Sedat YAŞAR, İsmail ÖZDEMİR, Mitat AKKOÇ

Synthesis and catalytic activity of ionic palladium N-heterocyclic carbene complexes

The synthesis of 3 benzimidazole-based ionic Pd(II)-NHC complexes (NHC:N -heterocyclic carbene) ispresented. The structures of the complexes are as follows: [NHC-PdBr 3 ] − [NHC] + . The ionic palladium(II)-NHC complexes were synthesized in high yields and were fully characterized by nuclear magnetic resonance spectroscopy, X-ray diffraction, LC-MS/MS, and elemental analysis. These complexes have been identified as active catalysts in Suzuki–Miyaura reactions in a solution of 2-propanol and water at room temperature for different aryl bromides.

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1. Miyaura N, Suzuki A. Stereoselective synthesis of arylated (E)-alkenes by the reaction of alk-1-enylboranes with aryl halides in the presence of palladium catalyst. Chemical Communications 1979; 19: 866-867. doi: 10.1039/C39790000866
2. Meijere A, Brase S, Oestreich M. Metal-Catalyzed Cross-Coupling Reactions and More. Weinheim, Germany: Wiley-VCH, 2014.
3. Kotha S, Lahiri K, Kashinath D. Recent applications of the Suzuki-Miyaura cross-coupling reaction in organic synthesis. Tetrahedron 2002; 58: 9633-9695. doi: 10.1016/S0040-4020(02)01188-2
4. Beller M, Dumrath A, Lubbe C. In Palladium-Catalyzed Coupling Reactions: Practical Aspects and Future Developments. Weinheim, Germnay: Wiley-VCH, 2013, pp. 445-489.
5. Lundgren RJ, Stradiotto M. Addressing challenges in palladium-catalyzed cross-coupling reactions through ligand design. Chemistry – A European Journal 2012; 18: 9758-9769. doi: 10.1002/chem.201201195
6. Fleckenstein CA, Plenio H. Sterically demanding trialkylphosphines for palladium-catalyzed cross coupling reactions– alternatives to PtBu 3. Chemiscal Society Reviews 2010; 39: 694-711. doi: 10.1039/B903646F
7. Scott NM, Nolan SP. Stabilization of organometallic species achieved by the use of N-heterocyclic carbene (NHC) ligands. European Journal of Inorganic Chemistry 2005; 326: 1815-1828. doi: 10.1002/ejic.200500030
8. Herrmann WA, Christian K. N-Heterocyclic carbenes. Angewandte Chemie International Edition 1996; 36: 2162- 2187. doi: 10.1002/anie.199721621
9. Valente C, Pompeo M, Sayah M, Organ MG. Carbon-heteroatom coupling using Pd-PEPPSI complexes. Organic Process Research & Development 2014; 18: 180-190. doi: 10.1021/op400278d
10. Valente C, Calimsiz S, Hoi KH, Mallik D, Sayah M et al. The development of bulky palladium NHC complexes for the most-challenging cross-coupling reactions. Angewandte Chemie International Edition 2012; 51: 3314-3332. doi: 10.1002/anie.201106131
11. Yaşar S, Şahin Ç, Arslan M, Özdemir İ. Synthesis, characterization and the Suzuki-Miyaura coupling reactions of N-heterocyclic carbene-Pd (II)-pyridine (PEPPSI) complexes. Journal of Organometallic Chemistry 2015; 776: 107-112. doi: 10.1016/j.jorganchem.2014.10.047
12. Deraedt C, Astruc D. “Homeopathic” palladium nanoparticle catalysis of cross carbon-carbon coupling reactions. Accounts of Chemical Research 2014; 47: 494-503. doi: 10.1021/ar400168s
13. Miyaura N, Yanagi T, Suzuki A, The palladium-catalyzed cross-coupling reaction of phenylboronic acid with haloarenes in the presence of bases. Synthetic Commununcation 1981; 11: 513-519. doi: 10.1080/00397918108063618
14. Martin R, Buchwald SL. Palladium-catalyzed Suzuki–Miyaura cross coupling reactions employing dialkylbiaryl phosphine ligands. Accounts of Chemical Research 2008; 41: 1461-1473. doi:10.1021/ar800036s
15. Silva JFM, Perez AFY, Almeida NP. An efficient and new protocol for phosphine-free Suzuki coupling reaction using palladium encapsulated and air-stable MIDA boronates in an aqueous medium. RSC Advances 2014; 4: 28148-28155. doi: 10.1039/c4ra03586k
16. Kantchev EAB, O’Brien CJ, Organ MG. Palladium complexes of N-heterocyclic carbenes as catalysts for crosscoupling reactions a synthetic chemist’s perspective. Angewandte Chemie International Edition 2007; 46: 2768-2813 doi: 10.1002/anie.200601663
17. Boubakri L, Yasar S, Dorcet V, Roisnel T, Bruneau C et al. Synthesis and catalytic applications of palladium Nheterocyclic carbene complexes as efficient pre-catalysts for Suzuki-Miyaura and Sonogashira coupling reactions. New Journal of Chemistry 2017; 41: 5105-5113. doi: 10.1039/C7NJ00488E
18. Huynh HV, Han Y, Ho JH, Tan GK. Palladium(II) complexes of a sterically bulky, benzannulated N-heterocyclic carbene with unusual intramolecular C−H· · ·Pd and Ccarbene · ··Br interactions and their catalytic activities. Organometallics 2006; 25: 3267-3274. doi: 10.1021/om060151w
19. Herrmann WA, Schwarz J. High-yield syntheses of sterically demanding bis(N-heterocyclic carbene) complexes of palladium. Organometallics 1999; 18: 4082-4089. doi: 10.1021/om990326k
20. Huynh HV, Ho JHH, Neo TC, Koh LL. Solvent-controlled selective synthesis of a trans-configured benzimidazoline2-ylidene palladium(II) complex and investigations of its Heck-type catalytic activity. Journal of Organometallic Chemistry 2005; 690: 3854-3860. doi: 10.1016/j.jorganchem.2005.04.053
21. Herrmann WA, Elison M, Fischer J, Köcher C, Artus GJ. Metal complexes of N-heterocyclic carbenes—A new structural principle for catalysts in homogeneous catalysis. Angewandte Chemie International Edition 1995; 34: 2371-2374. doi: 10.1002/anie.199523711
22. Touj N, Özdemir I, Yaşar S, Hamdi N. An efficient (NHC) copper (I)-catalyst for azide–alkyne cycloaddition reactions for the synthesis of 1,2,3-trisubstituted triazoles: Click chemistry. Inorganica Chimica Acta 2017; 467: 21- 32. doi: 10.1016/j.ica.2017.06.065
23. Ozdemir I, Temelli N, Günal S, Demir S. Gold(I) complexes of N-heterocyclic carbene ligands containing benzimidazole: Synthesis and antimicrobial activity. Molecules 2010; 15: 2203-2210. doi: 10.3390/molecules15042203
24. Akkoç M, İmik F, Yaşar S, Dorcet V, Roisnel T, Bruneau C et al. An efficient protocol for palladium Nheterocyclic carbene-catalysed Suzuki-Miyaura reaction at room temperature. Chemistry Select 2017; 2: 5729-5734. doi: 10.1002/slct.201701354
25. Yang L, Powell DR, Houser RP. Structural variation in copper(I) complexes with pyridylmethylamide ligands: structural analysis with a new four-coordinate geometry index, τ4 . Dalton Transaction 2007; 9: 955-964. doi: 10.1039/B617136B
26. Crabtree RH. Resolving heterogeneity problems and impurity artifacts in operationally homogeneous transition metal catalysts. Chemical Reviews 2012; 112: 1536-1554. doi: 10.1021/cr2002905
27. Yen SK, Koh LL, Hahn FE, Huynh HV, Hor TSA. Convenient entry to mono- and dinuclear palladium(II) benzothiazolin-2-ylidene complexes and their activities toward Heck coupling. Organometallics 2006; 25: 5105- 5112. doi: 10.1021/om060510n
28. Bedford RB, Blake ME, Butts CP, Holder D. The Suzuki coupling of aryl chlorides in TBAB–watermixtures. Chemical Communications 2003; 4: 466-467. doi: 10.1039/B211329E
29. Arvela RK, Leadbeater NE. A reassessment of the transition-metal free Suzuki-type coupling methodology. Organic Letters 2005; 7: 2101-2104. doi: 10.1021/jo048531j
30. DeVasher RB, Moore LR, Shaughnessy KH. Aqueous-phase, palladium-catalyzed cross-coupling of aryl bromides under mild conditions, using water-soluble, sterically demanding alkylphosphines. Journal of Organometallic Chemsitry 2004; 69: 7919-7927. doi: 10.1021/jo048910c
31. Stoe & Cie, X-AREA Version 1.18 and X-RED32 Version 1.04, Stoe & Cie, Darmstadt, Germany, 2002.
32. Sheldrick GM. Crystal structure refinement with SHELXL. Acta Crystallographica Section A 2015; A 71: 3-8. doi: 10.1107/S2053229614024218
33. Farrugia LJ. WinGX and ORTEP for Windows: an update. Journal of Applied Crystallography 2012; 45: 849-854. doi: 10.1107/S0021889812029111