Ligand Effects in Nickel Catalysis Anthony S. Grillo Chem 535 Seminar October 22, 2012 Transition Metals in Chemistry Organotransition Metal Chemistry, Hartwig, J. F. University Science Books: Mill Valley, CA, 2010. The Emergence of Nickel 8000 6000 4000 2000 Number of Publications Number 0 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 Publication Year www.scifinder.cas.org www.sigmaaldrich.com Crystal Field Theory Ni II most commonly square planar Tetrahedral with bulky ligands (PR3) Advanced Inorganic Chemistry, Cotton, F.A.; Wilkinson, G.; Murillo, C.A.; Bochmann, M., John Wiley and Sons, Inc.: New York, 1999. Modern Organonickel Chemistry Tamaru, Y. Wiley-VCH: Weinheim, Germany, 2005. Nickel-Catalyzed Processes • Hydrogenation Hibino, T.; Makino, K.; Sugiyama, T.; Hamada, Y. Chem. Cat. Chem. 2009, 1, 237-240. • Hydrocyanation/amination/arylation Robbins, D. W.; Hartwig, J. F. Science 2011, 333, 1423-1427. • Multi-Component Reactions Ogata, K.; Atsuumi, Y.; Shimada, D.; Fukuzawa, S. Angew. Chem. Int. Ed. 2011, 50, 5896-5899. Nickel-Catalyzed Processes • Nozaki-Hiyama-Kishi (NHK) Reaction Kobayashi, K.; Fujii, Y.; Hayakawa, I.; Kigoshi, H. Org. Lett. 2011, 13, 900-903. • Cycloadditions Nishimura, A.; Ohashi, M.; Ogoshi, S. J. Am. Chem. Soc. 2012, 134, 15692-15695. • Cycloisomerizations Phillips, J. H.; Montgomery, J. Org. Lett. 2010, 12, 4556-4559. Nickel-Catalyzed Processes • Reductive Couplings Shareef, A.-R.; Sherman, D. H.; Montgomery, J. Chem. Sci. 2012, 3, 892-895. 3 • sp Cross-Couplings Huang, C.-Y.; Doyle, A. G. J. Am. Chem. Soc. 2012, 134, 9541-9544. Outline Steric Effects Nickel Catalysis Electronic Chelation Effects Effects Electronic Effects Steric Effects Nickel Catalysis Electronic Chelation Effects Effects Electronic Effects - Phosphines Tolman, C. A. Chem. Rev. 1997, 77, 313-348. Electronic Effects – NHCs Dorta, R.; Stevens, E. D.; Scott, N. M.; Costabile, C.; Cavallo, L.; Hoff, C. D.; Nolan, S. P. J. Am. Chem. Soc. 2005, 127, 2485-2495. Electronic Effects – π-Systems Dewar, M. Bull. Soc. Chim. Fr. 1951, 18, C79. Chatt, J.; Duncanson, L. A. J. Chem. Soc. 1953, 2939. Vicic, D. A. et al. J. Am. Chem. Soc. 2006, 128, 13175-13183. sp3 Cross-Coupling Sp3 cross-coupling is difficult • Slow oxidative addition • Sterics, electronics • Prone to isomerization through β-Hydride Elimination • Metal-alkyl complexes are generally not stabilized M = Pd, Ni, Fe, Co, etc. X = I, Br, Cl, F, S, OR, NR SR, etc. 2, • Slow transmetalation M’ = B, Sn, Zn, Mg, Zr, Si, X, etc. R’ = Ar, Alkyl, Alkynyl, B, N, etc. Rudolph, A.; Lautens, M. Angew. Chem. Int. Ed. 2009, 48, 2656-2670. sp3 Cross-Coupling • Olefin necessary • Binding as π-acid decreases rate of β-Hydride Elimination • Makes nickel more electrophilic for transmetalation Devasagayaraj, A.; Studemann, T.; Knochel, P. Giovannini, R.; Studemann, T.; Devasagayaraj, A.; Angew. Chem., Int. Ed. 1995, 34, 2723-2725. Dussin, G.; Knochel, P. J. Org. Chem. 1999, 64, 3544-3553. sp3 Cross-Coupling Nielsen, D. K.; Doyle, A. G. Angew. Chem. Int. Ed. 2011, 50, 6056-6059. sp3 Cross-Coupling Vicic, D. A. et al. J. Am. Chem. Soc. 2006, 128, 13175-13183. Reductive Coupling of Alkynes Miller, K. M.; Huang, W. -S.; Jamison, T. F. J. Am. Chem. Soc. 2003, 125, 3442-3443. Montgomery, J.; Sormunen, G. J. Top. Curr. Chem. 2007, 279, 1-23. Sa-ei, K.; Montgomery, J. Org. Lett. 2006, 8, 4441. Reductive Coupling of Alkynes Evidence • Isotope Labeling • Kinetics • Stoichiometric Studies • IR • X-Ray Analysis Proposed TS Miller, K. M.; Huang, W. -S.; Jamison, T. F. Baxter, R. D.; Montgomery, J. J. Am. Chem. Soc. 2011, 133, 5728-5731. J. Am. Chem. Soc. 2003, 125, 3442-3443. Steric Effects Steric Effects Nickel Catalysis Electronic Chelation Effects Effects Steric Effects d10 Ni0 14e- Linear Species Tolman, C. A. Chem. Rev. 1997, 77, 313-348. Matsubara, K.; Miyazaki, S.; Koga, Y.; Nibu, Y.; Hashimura, T.; Clavier, H.; Nolan, S. P. Chem. Commun. 2010, 46, 841-861. Matsumoto, T. Organometallics, 2008, 27, 6020-6024. Reductive Ynal Couplings Malik, H. A.; Chaulagain, M. R.; Montgomery, J. Org. Lett. 2009, 11, 5734-5737. Malik, H. A.; Sormunen, G. J.; Montgomery, J. J. Am. Chem. Soc. 2010, 132, 6304-6305. Reductive Ynal Couplings Liu, P.; Montgomery, J.; Houk, K. N. J. Am. Chem. Soc. 2011, 133, 6956-6959. Reductive Ynal Couplings Shareef, A.-R.; Sherman, D. H.; Montgomery, J. Chem. Sci. 2012, 3, 892-895. Chelation Effects Steric Effects Nickel Catalysis Electronic Chelation Effects Effects Chelation Effects Zhou, J.; Fu, G. C. J. Am. Chem. Soc. 2003, 125, 14726-14727. Fischer, C.; Fu, G. C. J. Am. Chem. Soc. 2005, 127, 4594-4595. Chelation – Red. Elimination Bite Angle Dierkes, P.; van Leeuwen, P. W. N. M. J. Chem. Soc., Dalton Trans., 1999, 1519-1530. Chelation - β-H Elimination Pentacoordinate nickel decreases rate of β-H elimination • Coordinatively saturated (no agostic interactions) • More stabilized NiII center • Electrophilic NiII center Other Ligands Hu, X. Chem. Sci. 2011, 2, 1867-1886. sp3 Cross-Coupling Vechorkin, O.; Hu, X. L. Angew. Chem., Int. Ed. 2009, 48, 2937-2940. Binder, J. T.; Cordier, C. J.; Fu, G. C. J. Am. Chem. Soc. 2012, 134, 17003-17006. Summary Summary Advantages • Low costs relative to other transition metals • Diverse range of unique reactivities • Stereoconvergency and asymmetric advancements • The reactivity and regioselectivity are sensitive to ligand environment Disadvantages • Predictability, substrate scope, and generality are currently low • Small changes in substrate, conditions, catalyst have large effects on the efficiency of catalysis for each reaction class Future Directions • Production of more robust catalytic systems and precatalysts • Development of general reactivity rules/trends • Advancements to include carbon-heteroatom bond formation • Expand applications to include tertiary alkyl halides • 2-electron vs. 1-electron chemistry • Square planar vs. tetrahedral chemistry 1 vs. 2 electron Sq. Planar vs. Tetrahedral Modern Organonickel Chemistry Tamaru, Y. Wiley-VCH: Weinheim, Germany, 2005. Electronic Effects Steric Effects Nickel Catalysis Electronic Chelation Effects Effects Steric Effects Steric Effects Nickel Catalysis Electronic Chelation Effects Effects Chelation Effects Steric Effects Nickel Catalysis Electronic Chelation Effects Effects Nickel Catalysis Steric Effects Nickel Catalysis Electronic Chelation Effects Effects Acknowledgements Professor Burke Professor Hergenrother Chem 535 Burke Group .