學 生 : 王趙增 指導老師 : 于淑君 博士 2009 / 07 / 20 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 / 07 / 20 Department of Chemistry & Biochemistry Chung Cheng University

2. N-Heterocyclic Carbenes (NHC) L-type two electrons • 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. A.; Öfele, K; Elison, M.; Kühn, F. E.; Roesky, P. W. J. Organomet. Chem.1994, 480, C7-C9. 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 and Carbene-Copper(I) Complexes Linear di-coordination 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. Quantum Chemical Calculations for the N-Heterocyclic Carbene Complexes of MCl (M = Cu, Ag, Au) The trend of the bond energies for the metal fragments is AuCl > CuCl > AgCl Boehme, C. and Frenking, G.Organometallics 1998, 17, 5801-5809

8. Motivation • Using NHCs ligand to replace phosphine ligand in organomatallic catalysis. • In comparison with other transition metals (Cu, Au), silver has been virtually untouched as a catalyst for coupling reactions. • To promote silver-catalyzed three-component coupling of aldehyde, alkyne, and amine. • Easy recovered effectivetly recycled • Immobilization of NHC-Ag(I) complexs onto Au Nanoparticles.

9. Experimental Preparation of [Ag(hmim)2]PF6Complex

10. Experimental Preparation of Au NPs-Ag(I)(NHC)2(PF6) Space linker synthesis

11. Experimental Preparation of Au NPs-Ag(I)(NHC)2(PF6)

12. 1H NMR Spectra of [Hmim]HPF6 and [Ag(hmim)2]PF6 2H

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

14. ESI-MS Spectrum of [Ag(hmim)2]PF6 Experimental MS Data Calculated MS Data

15. 1225 cm-1 NHC H-C-C & H-C-N bending [Ag(hmim)2]PF6 a (hmim)HPF6 b 1168 cm-1 IR Spectra of [Hmim]HPF6 and [Ag(hmim)2]PF6

16. UV Spectra of [Hmim]HPF6 and [Ag(hmim)2]PF6 π π* 210 nm b [Ag(hmim)2]PF6 a a (hmim)2PF6 b

17. Single-Crystal X-ray Structure of [Ag(hmim)2]PF6 π π interaction Dihedral Angle 1.802o(221)

18. 1H, 31P, and 19F Spextra of Au-NPs-NHC Ligand -CH2SH *DMSO -SH * 19F NMR 31P NMR

19. Synthesis of Au NPs-Ag(I)-(NHC) Complex Cross-link network structure

20. 1H, 31P, and 19F ofAu NPs-Ag(I)-NHC Complex *DMSO 2 H 1 H * 19F NMR 31P NMR

21. 1H NMR Spectra of Ligand, Molcular and Au Nanoparticles *DMSO * * *

22. Synthesis of Octanethiol Protected Au-SR NPs Particle size 2.1 ± 1.12 nm

23. 230 nm Ligand centered π π* TEM Image and UV Spectrum of Au NPs-Immobilized (NHC) Ligand Particle size 3.1 ± 1.3 nm

24. TEM Image and EDS of Au NPs-Ag(I) Complex 245 nm Particle size: 2.1 ± 0.7 nm

25. NHC H-C-C & H-C-N bending 1229 cm-1 SH stretching 1169 cm-1 IR Spectra of Ligand & Au Nanoparticles series

26. Aldehyde, Amine, and Alkyne-coupling Reactions(A3-Coupling) 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

27. 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

28. Proposed Mechanism for the Three –Component Coupling C-H activation Chao J. L. et. al.Org. Lett., Vol. 5, No. 23, 2003,4473-4475

29. Ag(I)-Catalyzed A3-Coupling Reactions Reaction conditions: catalyst loading = 3 mol%; Benzaldehyde = 1.00 mmol; Pyperidine = 1.20 mmol; Phenylacetylene = 1.50 mmol solvent = 1.0 mL

30. Ag(I)-Catalyzed A3-Coupling Reactions

31. A3-Coupling Reactions of Aliphaticaldehyde, Amine, and Alkyne Reaction conditions: catalyst loading = 1.5 mol%; Benzaldehyde = 1.00 mmol; Piperidine = 1.20 mmol; Phenylacetylene = 1.50 mmol; Propionitrile = 1.0 mL

32. A3-Coupling Reactions of Aromaticaldehyde, Amine, and Alkyne Reaction conditions: catalyst loading = 3 mol%; Benzaldehyde = 1.00 mmol; Pyperidine = 1.20 mmol; Phenylacetylene = 1.50 mmol solvent = 1.0 mL

33. A3-Coupling Reactions of para-Formaldehyde, Amine, and Alkyne Reaction conditions: catalyst loading = 1.5 mol%; Benzaldehyde = 1.00 mmol; Piperidine = 1.20 mmol; Phenylacetylene = 1.50 mmol; Propionitrile = 1.0 mL

34. A3-Coupling Reactions of para-Formaldehyde, Amine, and Alkyne Reaction conditions: catalyst loading = 1.5 mol%; Benzaldehyde = 1.00 mmol; Piperidine = 1.20 mmol; Phenylacetylene = 1.50 mmol; Propionitrile = 1.0 mL

35. A3-coupling Reactions of Benzaldehyde, Amine, and Alkyne pKa 19.9 26.5 24 Reaction conditions: catalyst loading = 3 mol%; Benzaldehyde = 1.00 mmol; Pyperidine = 1.20 mmol; Phenylacetylene = 1.50 mmol solvent = 1.0 mL

36. Thermal v.s. Microwave Heating microwave thermal Convection transition Kappe, C. O.Angew. Chem. Int. Ed.2004, 43, 6250-6284.

37. A3-Coupling Reactions of Aliphaticaldehyde, Amine, and Alkyne Reaction conditions: catalyst loading = 1.5 mol%; Benzaldehyde = 1.00 mmol; Piperidine = 1.20 mmol; Phenylacetylene = 1.50 mmol; Propionitrile = 1.0 mL

38. A3-coupling Reactions of para-Formaldehyde, Amine, and Alkyne Reaction conditions: catalyst loading = 1.5 mol%; Benzaldehyde = 1.00 mmol; Piperidine = 1.20 mmol; Phenylacetylene = 1.50 mmol; Propionitrile = 1.0 mL

39. A3-Coupling Reactions of para-Formaldehyde, Amine, and Alkyne Reaction conditions: catalyst loading = 1.5 mol%; Benzaldehyde = 1.00 mmol; Piperidine = 1.20 mmol; Phenylacetylene = 1.50 mmol; Propionitrile = 1.0 mL

40. A3-Coupling Reactions of Benzaldehyde, Amine, and Alkyne Reaction conditions: catalyst loading = 1.5 mol%; Benzaldehyde = 1.00 mmol; Piperidine = 1.20 mmol; Phenylacetylene = 1.50 mmol; Propionitrile = 1.0 mL

41. Proposed Mechanism for the A3-Coupling Reaction

42. A3-Coupling Reactions Catalyzed by a Reusable PS-supported Ag(I)-NHC complex 1.Structure indefinite 2.Quantitative NHC-Silver (I) by ICP-Mass 24 h Wang, Li. P.; Zhang, Y. L.; Wang M. Tetrahedron Letters 49 2008 6650–6654

43. Quantitative by NMR 10 min AA analysis: 0.0038 mol/g ICP-Mass anlysis: 0.0039 mol/g 送校外 需時 2天 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

44. Reusable Au NPs-Ag(I)(NHC)2PF6 Catalyst for A3-Coupling Reaction Reaction conditions: Catalyst loading = 20 mol%; para-formaldehyde = 1.00 mmol; pyperidine = 1.10 mmol; phenylacetylene = 1.50 mmol propionitrile = 1.0 mL

45. Reactivity Comparision Between Au NPs-Ag(I)(NHC)(PF6) and [Ag(hmim)2]PF6 Reaction conditions: catalyst loading = 1.5 mol%; Benzaldehyde = 1.00 mmol; Piperidine = 1.20 mmol; Phenylacetylene = 1.50 mmol; Propionitrile = 1.0 mL

46. Conclusions 1.The air- and water-stable catalyst [Ag(hmim)2]PF6was synthesized and characterized by 1H- and13C-NMR, ESI-MS, IR, UV, X-ray. 2.We have developed a methodology to successfully immobilize [Ag(hmim)2]PF6onto surfaces of Au NPs.The structure of the supported Ag(I)-NHC complexcatalystwas characterized by 1H-NMR, IR, TEM, UV, EDS, AA, ICP-Mass. 3.Since the Au NPs- Ag(I) hybrid catalysts are highly soluble in organic solvents, their structures and reactions werestudied by simple solution NMR technique. 4. We have successfully demonstrated the catalytic activity of the Ag(I) complex for the three-component coupling reactionsof aldehyde, alkyne, and amine. 5. The Au NPs- Ag(I)catalystcan be quantitatively recovered and effectively reused for many times without any loss of reactivity.