學 生 : 王趙增 指導老師 : 于淑君 博士 2009 / 04 / 27 Department of Chemistry & Biochemistry

1. Molecular and Gold Nanoparticles Supported N-Heterocyclic Carbene Silver(I) Complexes – Synthesis, Characterization and Catalytic Applications 學 生 :王趙增 指導老師 : 于淑君 博士 2009 / 04 / 27 Department of Chemistry & Biochemistry Chung Cheng University

2. N-Heterocyclic Carbenes • NHCs are strongerσ-donors than the most electron rich phosphine - less likely to dissociate from the metal during the reaction • NHCs have come to replace phosphines in many organometallic and organic reactions • NHCs can be useful spectator ligands, tunable electronically and sterically • NHCs are most frequently prepared via deprotonation of the corresponding azolium salts

3. N-Heterocyclic Carbenes as Ligands - In the early 90's NHC were found to have bonding properties similar to trialklyphosphanes( -PR3 ) and alkylphosphinates( -OP(OR)R2 ). - compatible with both high and low oxidation state metals - examples: - reaction employing NHC's as ligands: Herrmann, W. Angew. Chem. Int. Ed.2002, 41, 1290-1309.

4. The Applications of Ag(I) NHC • Silver(I)-Carbene Complexes as Carbene Transfer Agents • Addition of arenes to imines • Aza-Diels-Alder reaction • Asymmetric aldol reaction • Barbier-Grignard-type reaction

5. The First Silver(I)-Carbene Complexes Arduengo.A.J,et.al. Organometallics 1993, 21, 3405-3409

6. Silver(I)-Carbene Complexes as Carbene Transfer Agents Wang, H. M. J.; Lin, I. J. B. Organometallics1998, 17, 972-975

7. Motivation • Using NHCs ligand to replace phosphine ligand in organomatallic catalysis. • -Immobilization of NHC- Ag(I) complexs onto Au Nanoparticles • Recyclable catalysts and their Applications in solvent-free system. • Developing a homogeneous catalyst for aldehyde alkyne and amine coupling.

8. Experimental Preparation of [Ag(hmim)2]PF6 Complex

9. 1H NMR Spectra of [Hmim]HPF6, [Ag(hmim)2]PF6 H 2H *H2O *DMSO *H2O 2H 2H *DMSO

10. 13C NMR Spectra of [Hmim]HPF6, [Ag(hmim)2]PF6 *DMSO C *DMSO c

11. Change Temperature 1H NMR Spectra of [Ag(hmim)2]PF6 Temp.:250C Temp.:100C H H

12. ESI-MS Spectrum of [Ag(hmim)2]PF6

13. Ionic Liquids As Stabilizing Agents for NPs • Addition of (a) HCl, (b) HBr, (c) HBF4, (d) HI,and (e) HPF6. • UV-vis absorption spectra corresponding to (a), (d), and (e) in photograph A. Itoh, H.; Naka, K.; Chujo, Y. J. Am. Chem. Soc. 2004, 126, 3026-3027.

14. Synthetic Strategy

15. Synthesis of Octanethiol Protected Au-SR NPs Particle size distribution = 2.1 ± 1.12 nm Brust, M,; Walker, M.; Bethell, D,; Schiffrin, D, J.; Whyman, R.J. Chem. Soc. Chem. Commun. 1994, 801-802.

16. Nano-Gold Surface-Immobilized ILs

17. 1H, 31P, and 19F of Au NPs-SupportedIonic Liquid 31P NMR 19F NMR

18. TEM and UV Spectra of Au NPs-SupportedIonic Liquid Particle size distribution =3.1 ± 1.3 nm

19. Au NPs-Supported Ag(I) Complexes via Thiolated NHC Carbene Ligatior

20. 1H, 31P, and 19F ofAu NPs-Supported Ag(I) Complexes via Thiolated NHC Carbene Ligatior 2 H 1 H 31P NMR 19F NMR

21. TEM of Au NPs-Supported Ag(I) Complexes via Thiolated NHC Carbene Ligatior

22. 1H NMR Spectra of Ligand, Molcular and Au Nanoparticles series 2H 2H 2H 2H

23. 1251cm-1 Au-IL-Ag 1571cm-1 Au-IL IL-SH imidazole H–C–C & H–C–N bending imidazole ν (ring stretching) Au-SR 1560 cm-1 1240 cm-1 IR Spectra of Ligand & Au Nanoparticles series -SH stretching

24. A3-coupling reactions Have attracted much attention from organic chemists for the coupling products, propargylamines, which are major skeletons or synthetically versatile building blocks for the preparation of many nitrogen-containing biologically active compounds J. Org. Chem. 1995, 60, 1590-1594

25. The First Silver-Catalyzed Three-Component Coupling of Aldehyde, Alkyne, and Amine Chao J. L. et. al.Org. Lett., Vol. 5, No. 23, 2003,4473-4475

26. Proposed Mechanism for the Three –Component Coupling C-H activation Silver(I) Oxidation Silver (I) Reduction Chao J. L. et. al.Org. Lett., Vol. 5, No. 23, 2003,4473-4475

27. Reaction conditions: Catalyst loading =1.5 mol%; carried out on a 1 mmol scale aldehyde/amine/alkyne = 1:1.2:1.5, 1000C, 1 mL of solvents.

28. Reaction conditions: Catalyst loading =1.5 mol%; carried out on a 2 mmol scale aldehyde/amine/alkyne = 1:1.2:1.5, 1000C, 1 mL of Propionitrile.

29. Reaction conditions: Catalyst loading = 3 mol%; carried out on a 1mmol scale aldehyde/amine/alkyne = 1:1.2:1.5, 1000C, 1 mL of Propionitrile.

30. Three-component coupling reactions catalyzed by a reusable PS-supported NHC–Ag(I) under solvent-free reaction conditions Li P. , Wang L. , Zhang Y. , Wang M. Tetrahedron Letters 49 (2008) 6650–6654

31. 4 H 2 H d6-DMSO 0.25 : 0.13 = X : 0.03725 X = 0. 07164 mmol – lignad 0.07164×0.5 = 0.0358 mmol- metal center 0.0358/9 = 0.004 mol/g Au-[hmim]2AgPF6: 9 mg 1,2,4,5-tetramethylbenzene: 5 mg

32. Reaction conditions: Catalyst loading = 20mol%;para-formaldehyde(1.0mmol),piperidine(1.1mmol) phenylacetylene(1.1mmol) at room temperature for 24 h

33. Conclusions 1.We have developed a method to successfully immobilize (NHC)2AgPF6 onto surfaces of Au NPs was characterized by 1H-NMR,IR,TEM. 2.The air- and water- stable catalyst [Ag(hmim)2]PF6 was characterized by 1H- and 13C NMR, LC-MS, IR. 3. We have successfully demonstrated the catalytic activity of the Ag(I) complex for three component (aldehyde, alkyne, and amine) coupling reaction. 4. The Au NPs- Ag(I) hybrid catalysts can be easily recovered and reused many times without significant loss of reactivity.

35. Immobilization of AgPF6(NHC) onto Surfaces of Au-NPs *H2O *DMSO 2H H *DMSO *H2O 2H

36. IL-SH Au-IL Au-IL-Ag

37. Li P. , Wang L. , Zhang Y. , Wang M. Tetrahedron Letters 49 (2008) 6650–6654