Reporter: You Lin. Supervisor: Prof. Yang Prof. Chen Prof. Tang

Transcription

1 Dances With Metals Reporter: You Lin Supervisor: Prof. Yang Prof. Chen Prof. Tang Johnson, J. B.; Rovis, T. Angew. Chem. Int. Ed. 2008, 47, Crabtree, R. H. The rganometallic Chemistry of the Transition Metals, Wiley, New York, 2003

2 Why did I choose this topic? Chiral lefin Ligands for Asymmetric Catalysis (Group Meeting)

3 Contents I. Dancer ---- Metal-lefin Complexes II. Dance Step ---- rganometallic Transformations III. Dancing ---- The Effect of lefin on Catalytic Reactions IV. Ballet ---- Chiral lefins as Ligands in Asymmetric Catalysis V. Ending ---- Summary &. Acknowledgement

4 Contents I. Dancer ---- Metal-lefin Complexes II. Dance Step ---- rganometallic Transformations III. Dancing ---- The Effect of lefin on Catalytic Reactions IV. Ballet ---- Chiral lefins as Ligands in Asymmetric Catalysis V. Ending ---- Summary &. Acknowledgement

5 1827, Zeise reports first metal-olefin complex - K + H H EtH + K 2 [PtCl 4 ] H H H 2 Cl Pt Cl Cl Zeise's salt π donation σ donation

6 1950s, Dewar-Chatt-Duncanson model M M donation back-donation π back-donation I. Weakens and lengthens the C-C bond rehydridization of carbon centers Free alkene none Zeise s salt Pt(II) Å Å Pt(PPh 3 ) 2 C 2 H 4 Pt(0) 1.43 Å Tolman, C. A. J. Am. Chem. Soc. 1974, 96, 2780.

7 II. Metal-olefin bond strength is determined by π back-donation Electron-rich metal center Electron-deficient olefin III. Back-donation increases with the principal quantum number of metal center Soft Soft Interactions Tolman, C. A. J. Am. Chem. Soc. 1974, 96, 2780.

8 IV. The Trans Effect The effect of a coordinated group on the rate of substitution reaction of ligands trans to itself More electron-deficient (good π accepter) Decrease electron density Stronger trans effects V. Bonding Strength Me B(C 6 F 5 ) 4 - Me Zr t Bu R 4800 ~

9 Contents I. Dancer ---- Metal-lefin Complexes II. Dance Step ---- rganometallic Transformations III. Dancing ---- The Effect of lefin on Catalytic Reactions IV. Ballet ---- Chiral lefins as Ligands in Asymmetric Catalysis V. Ending ---- Summary &. Acknowledgement

10 xidative Addition M n+ M (n+2)+ Reductive Elimination xidative Additive Increase coordination number More labile Increase electron density More electron-rich More electron-deficient Valence state increased More electron-rich Coordination number increased More Coordination site

11 lefin Effects on xidative Additive Altering the electronic nature Metal-olefin bond: dominated by π back-donation Decrease the electron density on metal center Reduces the reactivity of a metal center for oxidative addition Amatore, C.; Jutand, A.; Khalil, F.; M Barki, M. A.; Motter, L. rganometallics 1993, 12, Mace, Y.; Kapdi, A. R.; Fairlamb, I. J. S. Jutand, A. rganometallics 2006, 25, 1795.

12 Increasing the coordination number Labile, easily dissociate [Pd 2 (dba) 3 ] > [Pd(dba) 2 ], lower concentration of olefin Example: [Pd( 3 -C 3 H 5 )Cl] + olefin [Pd(olefin) n ] C 2 Me Cl C 2 Me + C 2 Me PhBu 3 Sn PdCl syn PdCl anti lefin: None 45 : 55 1,5-cod 10 : 90 NC CN 97 : 3 Me 2 C Me 2 C C 2 Me C 2 Me 97 : 3 97 : 3 More electron-rich metal anti More electron-deficient Formation of π-allyl syn Kurosawa, H.; Kajimaru, H.; goshi, S.; Yoneda, H.; Miki, K. Kasa, N.l Murai, S.; Ikeda, I. J. Am. Chem. Soc. 1992, 114, 8417.

13 xidative Addition M n+ M (n+2)+ Reductive Elimination Reductive Elimination Decrease coordination number Bulky Decrease electron density More electron-deficient Valence state decreased More electron-deficient Coordination number decreased Bulky

14 lefin Effects on Reductive Elimination More electron-deficient olefin Altering the electronic nature Induce reductive elimination ccupation of a vacant coordination site Prevent β-hydride elimination

15 Example: Pd L Additive Yield C(20):C(16) none 51% 2:3 C(20): less sterically congested Closer to Pd 96% >7:1 stronger electron-donation than C(16) tans to good π accepter Temple, J. S.; Schwartz, J. J. Am. Chem. Soc. 1980, 102, Temple, J. S.; Riediker, M.; Schwartz, J. J. Am. Chem. Soc. 1982, 104, 1310.

16 Contents I. Dancer ---- Metal-lefin Complexes II. Dance Step ---- rganometallic Transformations III. Dancing ---- The Effect of lefin on Catalytic Reactions IV. Ballet ---- Chiral lefins as Ligands in Asymmetric Catalysis V. Ending ---- Summary &. Acknowledgement

17 lefin-containing Substrates Br Ph + Et 2 Zn [Ni(acac) 2 ](7.5mol%) LiI (20 mol%) THF, -35 o C Et Ph Br Ph + Et 2 Zn [Ni(acac) 2 ](7.5mol%) LiI (20 mol%) THF, -35 o Cto25 o C XZn Ph Accelerate reductive elimination Devasagayaraj, A.; Studemann, T.; Knochel, P. Angew. Chem. Int. Ed. Engl. 1995, 34,

18 lefin-containing Substrates NTs [Pd 2 (dba) 3 ] Ts N Pd(phen) unsaturated saturated Substrates: N phen N unsaturated 45% saturated NR Bu 2 C NTs 44% NTs NR TBS NTs NR NTs NR Accelerate oxidative addition Ts H N Unreactive Pd 0 Ney, J. E.; Wolfe, J. P. J. Am. Chem. Soc. 2006, 128,

19 lefin-containing Substrates Stille: active inactive inactive Heck: active inactive Stille and Heck coupling: reaction rate decreased by increased concentrations of the nucleophile.

20 Substrate Directing Effects 1991, Trost reported an early example of olefin directing effects. E E Pd(Ac) 2 (3 mol%) C 6 H 6,60 o C, 2h E E + E E saturated saturated 1 : >99 unsaturated unsaturated 15 : , Krafft reported the use of olefin to direct the regio-chemistry Pd PPh 3 Trost, B. M.; Lautens, M.; Chan, C.; Jebaratnam, D. J.; Meuller, T. J. Am. Chem. Soc. 1991, 113, 636. Krafft, M. E.; Sugiura, M.; Abboud, K. A. J. Am. Chem. Soc. 2001, 123, 4735.

21 2004, Jamison observed olefin direct the addition of aldehydes to alkyne BEt 2 Ni H R Et 3 B With Cyp3P L Ni R R H H 3 ipr R H R H No Cyp3P 3 R ipr Ni R' Et 3 B R Miller, K. M.; Luanphaisarnnont, T.; Molinaro, C.; Jamison, T. F. J. Am. Chem. Soc. 2004, 126, Miller, K. M.; Jamison, T. F. J. Am. Chem. Soc. 2004, 126, Moslin, R. M.; Jamison, T. F. rg. Lett. 2006, 8, 455.

22 2007, Rovis explored using alkylation chemistry provide directing effects. H H H + Et 2 Zn [Ni(cod 2 )] THF, 0 o C H Et C 2 Me R R = Ph 86% 98 :2 then TMSCHN 2 R R = nbu 98% 98 :2 R = Bn 95% 98 :2 Rovis, T.; Moore, J. L.; Rogers, R. L. Angew. Chem. Int. Ed. Engl. 2007, 46,

23 lefin-containing Catalyst 2004, Fairlamb studied the reactivity of Pd catalyst by changing ligand dissociation. Suzuki-Miyaura coupling: rate-limiting process is ligand dissociation/xidative addition Dissociation Strengthening The presence of olefins appears to have a great influence on the oxidative-addition step Fairlamb, I. J. S. Kapdi, A. R.; Lee, A. F. rg. Lett. 2004, 6,

24 2006, Scrivanti found the role of stabilization of catalyst. X = C 2 Me X = CN Rapidly decomposed R. T. Good ligand for Suzuki coupling: 82% Rapidly decomposed 90 o C 54% Resistant to decomposition Identical conditions Dissociate to form the active species Stabilize the intermediates Crociani, B.; Antonaroli, S.; Marini, A.; Matteoli, U.; Scrivanti, A. Dalton Trans. 2006,

25 Exogenous Additives to Catalytic Reactions 1976, Miller reported rhodium-catalyzed cyclization Coordination of ethylene precedes decarbonylation Increased substrate concentrations 1985, Schwartz observed cross coupling of allyl Pd with allyl tin Facilitation of reductive elimination Lochow, C. F.; Miller, R. G. J. Am. Chem. Soc. 1976, 98, Fairlie, D. P.; Bosnich, B. rganometallics 1988, 7, 936. Gollaszewski, A.; Schwartz, J. rganometallics 1985, 4, 417.

26 1986, Sustmann reported the use of additive olefin to dictate product selectivity. Reductive elimination vs. β-h elimination More electron-deficient &. Decrease coordination number Sustmann, R.; Lau, J.; Zipp, M. Tetrahedron Lett. 1986, 27,

27 1992, Kurosawa examined cross coupling of various allylic chlorides with B, Zn, Sn Kurosawa, H.; Kajimaru, H.; Miyoshi, M. A.; hnishi, H.; Ikeda, I. J. Mol. Catal. 1992, 74, 481..

28 1998, Knochel found a series of styrenes as exogenous olefin. Giovannini, R.; Studemann, T.; Dussin, G.; Knochel, P. Angew. Chem. Int. Ed. Engl. 1998, 37, Korn, T. J.; Knochel, P. Angew. Chem. Int. Ed. Engl. 2005, 117, 3007.

29 2002, Rovis reported styrene as exogenous olefin in alkylation of anhydrides R R R R Ni N N N Ni N Et 2 Zn EtZn Et R R R R ZnEt N Ni Et N Facilitation of reductive elimination Stabilization of catalyst Bercot, E. A.; Rovis, T. J. Am. Chem. Soc. 2002, 124, 174. Johnson, J. B.; Bercot, E. A.; Rowley, J. M.; Coates, G. W.; Rovis, T. J. Am. Chem. Soc. 2007, 129, 2718.

30 2007, Rovis reported asymmetric version Cycle A with styrene N Ni P Rate A : Rate B = 4 : 1 Ph Styrene plays an intimate role in the enantioselectivity-determining event and accelerate the oxidative addition N Ni P Cycle B no styrene Johnson, J. B.; Bercot, E. A.; Rowley, J. M.; Coates, G. W.; Rovis, T. J. Am. Chem. Soc. 2007, 129, 2718.

31 2000, Catellani developed norbornene as exogenous olefin I + 2PrBr + Ph B(H) 2 I + nbui + Pd(Ac) 2 K 2 C 3,DMF,RT -HI Pd(Ac) 2 K 2 C 3,DMF,RT Pr Pd L L I Product L Pd L RI nbu Pr I L Pd L R R E R Pd L R L I nbu C 2 Me Catellani, M.; Motti, E.; Minari, M. Chem. Commun. 2000, 157.

32 2002, Kambe reported diene or tetraene as exogenous olefin Terao,J.; Todo, H.; Watanabe, H.; Ikumi, A.; Kambe, N. Angew. Chem. Int. Ed. Engl. 2004, 43, 6180.

33 Contents I. Dancer ---- Metal-lefin Complexes II. Dance Step ---- rganometallic Transformations III. Dancing ---- The Effect of lefin on Catalytic Reactions IV. Ballet ---- Chiral lefins as Ligands in Asymmetric Catalysis V. Ending ---- Summary &. Acknowledgement

34 1962, Cope prepared the first chiral olefin 1981, Hosokawa developed catalytic asymmetric reaction with chiral allyl ligand 2003, Hayashi's report of chiral diene ligands in rhodium catalysis

35 Phosphino-lefin Ligand Good Chiral environment Strong coordination ability Classes of chiral phosphino-olefin ligands

36 2004, Grutzmacher developed the tropp type ligand 2005, Hayashi developed the norbornene type ligand 2006, Widhalm developed the binapthyl type ligand Ph H Rh P Ph BF 4 thf NCMe "binaphthyl" type

37 Amino-lefin Ligand Good Chiral environment M N likely to be replaced by a stronger σ-donor Weaker than P-olefin ligand Classes of chiral amino-olefin ligands Grutzmacher

38 2005, Grutzmacher developed the tropp type ligand Cl Ph NH Ir N H C Ph [Cat.] Maire, P.; Breher, F.; Schonberg, H.; Grutzmacher, H. organometallics 2005, 24, 3207.

39 Chiral Diene Ligand Classes of chiral diene ligands

40 Benchmark reaction Bn Hayashi 2003 Bn 94% yield 96% ee Bn Rh Favored Ph Bn Ph Rh Ph Ph Bn Hayashi 2006 Bn 93% yield 83% ee 100% yield 96% ee Me Me Me Me Carreira 2004 Me 87% yield 95% ee F F F F R R R = (-)-menthol Hayashi % yield 99% ee

41 Benchmark reaction Ph Ph H Grutzmacher % yield 62% ee H Ph Laschat / 2007 Lin / % yield 91% ee MsHN Du 2010 NHMs 96% yield 95% ee TsN Me Yu 2011 n-bu 89% yield 91% ee

42 1, 2-Addition Cl Bn N Ts diene* = Bn (PhB) 3 H + [RhCl(diene*) 2 ] 2 HN Ts H Cl 96% Y, 98% ee Carborhodation Tokunaga, N.; tomaru, Y.; kamoto, K.; Ueyama, K.; Shintani, R.; Hayashi, T. J. Am. Chem. Soc. 2004, 126, Shintani, R.; kamoto, K.; tomaru, Y.; Ueyama, K.; Hayashi, T. J. Am. Chem. Soc. 2005, 127, 54.

43 Contents I. Dancer ---- Metal-lefin Complexes II. Dance Step ---- rganometallic Transformations III. Dancing ---- The Effect of lefin on Catalytic Reactions IV. Ballet ---- Chiral lefins as Ligands in Asymmetric Catalysis V. Ending ---- Summary &. Acknowledgement

44 Summary Metal: d π electron More electron-rich ligand Weaken metal-olefin bond increase the electron density Accelerate oxidative addition More electron-deficient ligand Strengthen metal-olefin bond Decrease the electron density Stabilized catalyst Accelerate reductive Elimination lefin: Common in substrate Chiral environment

45 Acknowledgement Prof. Yang, Prof. Chen & Prof. Tang Mr. Yu Ruocheng Mr. Zhou Zhiyao; Mr. Li Yuanhe All Members Thank you!