Cross coupling olefination methods

Cross coupling olefination methods Metathesis reaction Olefin metathesis • 1956 – Initial discovery by Ziegler • 1971 – Mechanism postulated by Chauvin • 1990 – Schrock describes the first welldefined Mo catalyst • 1993 – Ru catalyst system proposed by Grubbs • 2005 – Grubbs, Schrock and Chauvin share Nobel Prize Mechanism of olefin metathesis Development of Olefin metathesis catalyst Classes of olefin metathesis Ring Closing Metathesis (RCM) Cross Metathesis (CM) Ring Opening Metathesis Polymerization (ROMP) Acyclic Diene Metathesis Polymerization(ROMP) Cross metathesis • Homodimerization • Heterodimerization Cross metathesis • Regioselectivity in CrossMetathesis E selective Steric bulk at allylic position Crowe, W. Tet. Lett. 1996, 37, 2117 Grubbs, R. et al. J. Am. Chem. Soc. 2000, 122, 58 Cross metathesis • Regioselectivity in CrossMetathesis E selective Electronpoor olefins Grubbs, R. J. Am. Chem. Soc. 2000, 122, 3783 Cross metathesis • Regioselectivity in CrossMetathesis E selective Electronpoor olefins Grubbs, R. Angew. Chem. Int. Ed. 2001, 40, 1277 Grubbs, R. Synlett. 2001, 1034 Grela, K. and Bieniek, M. Tet. Lett. 2001, 42, 6425 Cross metathesis • Regioselectivity in CrossMetathesis E selective Electronpoor olefins Bouzbouz, S. and Cossy, J. Org. Lett. 2001, 3, 1451 Cross metathesis • Regioselectivity in CrossMetathesis E selective Electronpoor olefins Bouzbouz, S. and Cossy, J. Org. Lett. 2001, 3, 1451 Cross metathesis • Regioselectivity in CrossMetathesis E selective Other useful functional groups Miyaura, N. Synlett. 2002, 128 Grubbs, R. Angew. Chem. Int. Ed. 2002, 41, 3172 Grubbs, R. J. Am. Chem. Soc. 2000, 122, 3783 Lautens, M. Angew. Chem. Int. Ed. 2000, 39, 4079 Cross metathesis • Regioselectivity in CrossMetathesis Z selective • First Zselective Metathesis Catalyst – Effective in CM of alkenes, enol ethers, ROCM • Grubbs Zselective Ru Catalyst – Highly reactive (