1. 1 Sébastien Goudreau Literature meeting : 13-02-2007 Rhodium(I) Chemistry Rhodium(I)

2. 2 Rhodium Number 45 [Kr]4d 8 5s 1 Hard silvery white and durable metal that has a high reflectance. (Use in jewellery) Does not form an oxide, is not attacked by acids. Very high melting point : 2236°C It is the most expensive precious metal. http://en.wikipedia.org/wiki/Rhodium

3. 3 Applications The primary use of this element is as an alloying agent for hardening platinum and palladium.platinumpalladium It is used as an electrical contact material due to its low electrical resistance, low and stable contact resistance, and its high corrosion resistance. electrical resistancecorrosion Plated rhodium, made by electroplating or evaporation, is extremely hard and is used for optical instruments.electroplating This metal finds use in jewelry and for decorations.jewelry It is also a highly useful catalyst.catalyst http://en.wikipedia.org/wiki/Rhodium

4. 4 History Rhodium was discovered in 1803 by William Hyde Wollaston soon after his discovery of palladium. Wollaston made this discovery in England using crude platinum ore that he presumably obtained from South America. His procedure involved dissolving the ore in aqua regia (HCl + HNO 3 ), neutralizing the acid with NaOH. He then precipitated the platinum metal by adding NH 4 Cl, as ammonium chloroplatinate. The element palladium was removed as palladium cyanide after treating the solution with mercuric cyanide. The material that remained was a red rhodium(III) choride. (Greek rhodon meaning "Rose") Wilkinson’s catalyst : RhCl(PPh 3 ) 3 : 1965 William Hyde Wollaston Geoffrey Wilkinson Nobel Prize 1973 Wilkinson et al. J. Org. Chen. Chem. Commun., 1965, 7, 131. http://en.wikipedia.org/wiki/Rhodium

5. 5 Rhodium(I) in Organic Chemistry 1)C-H and C-C bond activation 2)Hydrorhodation A) Hydrogenation B) Hydroarylation C) Hydroalkynation D) Hydroacylation E) Hydrosilylation F) Hydroboration 3) Addition A) 1,4 addition B) 1,2 addition C) Coupling 4) Sigmatropic Rearrangement A) Cycloaddition B) Alder-ene 5)  -Allyl chemistry 6)  -aryl elimination Square plane

6. 6 1) C-H and C-C bond activation (a) Milstein et al. Angew. Chem. Int. Ed. 2007, 46, ASAP. (b) Bergman et al. J. Am. Chem. Soc. 2006, 128, 2452. (c) Milstein et al. J. Am. Chem. Soc. 2003, 125, 11041. Prof. David Milstein The Weizmann Institute of Science, Israel

7. 7 2) Hydrorhodation A)Hydrogenation B) Hydroarylation C) Hydroalkynation D) Hydroacylation E) Hydrosilylation F) Hydroboration

8. 8 A) Hydrogenation Zassinovich, Mestroni Chem. Rev. 1992, 92, 1051 and references cited therein

9. 9 Enantioselective Hydrogenation Burk et al. J. Am. Chem. Soc. 1993, 115, 10125.

10. 10 B) Hydroarylation Pfeffer et al. Chem. Rev. 2002, 102, 1731.

11. 11 B) Hydroarylation : exemple Pfeffer et al. Chem. Rev. 2002, 102, 1731.

12. 12 B) Hydroarylation : exemple Pfeffer et al. Chem. Rev. 2002, 102, 1731.

13. 13 C) Hydroalkynation Pfeffer et al. Chem. Rev. 2002, 102, 1731.

14. 14 C) Hydroalkynation : exemples Pfeffer et al. Chem. Rev. 2002, 102, 1731.

15. 15 D) Hydroacylation Pfeffer et al. Chem. Rev. 2002, 102, 1731.

16. 16 D) Hydroacylation : exemples Pfeffer et al. Chem. Rev. 2002, 102, 1731.

17. 17 D) Hydroacylation : example Pfeffer et al. Chem. Rev. 2002, 102, 1731.

18. 18 Intramolecular Hydroacylation Pfeffer et al. Chem. Rev. 2002, 102, 1731.

19. 19 C) Hydrosilylation

20. 20 C) Hydrosilylation Pfeffer et al. Chem. Rev. 2002, 102, 1731.

21. 21 D) Hydroboration Guiry et al. Adv. Synth. Catal. 2005, 347, 609.

22. 22 D) Hydroboration Guiry et al. Adv. Synth. Catal. 2005, 347, 609.

23. 23 Hydrorhodation : Conclusion Atom efficient Mild conditions Good alternative route Regioselectivity : can be problematic Enantioselectivity : can be very good

24. 24 2) Addition reaction A)1,4 addition B)1,2 addition C)Coupling

25. 25 A) 1,4 addition reaction M : Organoboron (organostannate, organosilane, organobismuth) R : Aryl Fagnou, Lautens Chem. Rev. 2003, 103, 169.

26. 26 A) 1,4 Addition : exemples Fagnou, Lautens Chem. Rev. 2003, 103, 169.

27. 27 A) 1,4 Addition : examples Fagnou, Lautens Chem. Rev. 2003, 103, 169.

28. 28 A) 1,4 Addition : examples Fagnou, Lautens Chem. Rev. 2003, 103, 169.

29. 29 A) 1,4 Addition : examples Fagnou, Lautens Chem. Rev. 2003, 103, 169.

30. 30 Fagnou, Lautens Chem. Rev. 2003, 103, 169. A) 1,4 Addition : examples

31. 31 Krische’s chemistry

32. 32 Krische’s chemistry Krische et al. J. Am. Chem. Soc. 2002, 124, 15156.

33. 33 B) 1,2 Addition reaction Fagnou, Lautens Chem. Rev. 2003, 103, 169. M : Organoboron (organostannate, organosilane, organobismuth) R : Aryl

34. 34 B) 1,2 Addition : exemples Fagnou, Lautens Chem. Rev. 2003, 103, 169.

35. 35 Ellman et al. J. Am. Chem. Soc. 2005, 127, 1092. B) 1,2 Addition : exemples

36. 36 (a) Fagnou, Lautens Chem. Rev. 2003, 103, 169. (b) Iwasawa et al. J. Am. Chem. Soc. 2006, 128, 8706. B) 1,2 Addition : exemples

37. 37 Krische’s chemistry Krische et al. J. Am. Chem. Soc. 2006, 128, 718.

38. 38 C) Coupling Fagnou, Lautens Chem. Rev. 2003, 103, 169.

39. 39 Addition reaction : Conclusion Mild conditions : presence of water Good enantioselectivity Excess of organoboron needed

40. 40 4) Sigmatropic rearrangement A) Cycloaddition B) Alder-ene 2+2+2 2+2+1 (Pauson-Khand) 3+2 4+2 5+2 6+1 4+2+2 Paul A. Wender Stanford University, USA

41. 41 Mecanism : [2+2+2] Lautens et al. Chem. Rev. 1996, 96, 49.

42. 42 [2+2+1] Cycloaddition : Pauson-Khand Reaction Lautens et al. Chem. Rev. 1996, 96, 49.

43. 43 [2+2+1] Cycloaddition : Pauson-Khand Reaction Jeong et al. J. Am. Chem. Soc. 2000, 122, 6771.

44. 44 [3+2] Cycloaddition Wender et al. J. am. Chem. Soc. 2006, 128, 14814.

45. 45 [4+2] Cycloaddition : Diels Alder Mikami et al. J. Am. Chem. Soc. 2006, 128, 12648.

46. 46 [5+2] Cycloaddition Saito et al. J. Org. Chem. 2006, 71, 6437.

47. 47 [6+1] cycloaddition Wender et al. Angew. Chem. Int. Ed. 2006, 45, 3957.

48. 48 [4+2+2] and [2+2+2+1] cycloaddition Ojima et al. Org. Lett. 2004, 6, 3589. Wender et al. J. Am. Chem. Soc. 2006, 128, 5354.

49. 49 B) Alder-ene Zhang et al. J. Am. Chem. Soc. 2002, 124, 8198.

50. 50 Conclusion Access to a large variety of cycles Regioselectivity : need linkers

51. 51 5) Allylic (a) P.A. Evans et al. J. Am. Chem. Soc. 2004, 126, 8642. (b) P.A. Evans et al. J. Am. Chem. Soc. 2003, 125, 8974. (c) P.A. Evans et al. J. Am. Chem. Soc. 2002, 124, 7882.

52. 52 6)  -aryl elimination John F. Hartwig Yale University, USA

53. 53 Conclusion 1)C-H and C-C bond activation 2)Hydrorhodation A) Hydrogenation B) Hydroarylation C) Hydroalkynation D) Hydroacylation E) Hydrosilylation F) Hydroboration 3) Addition A) 1,4 addition B) 1,2 addition C) Coupling 4) Sigmatropic Rearrangement A) Cycloaddition B) Alder-ene 5)  -Allyl chemistry 6)  -aryl elimination Square plane

54. 54 Conclusion