Enantioselective allylic substitution catalyzed by an iridium complex: remarkable effects of the counter cation

Abstract

Allylic substitution of a methyl carbonate of cinnamyl alcohol with the anion of dimethyl malonate gave the branched olefin with high enantioselectivity in the presence of (S)-1,1′-binaphthyl-2,2′-diyl phenyl phosphite when a combination of lithium and zinc was used as counter cation.

References

1. R. Takeuchi and M. Kashio, J. Am. Chem. Soc., 1998, 120, 8647; Angew. Chem., Int. Ed. Engl., 1997, 36, 263.
2. J. R. Janssen and G. Helmchen, Tetrahedron Lett., 1997, 38, 8025.
3. B. Bartels and G. Helmchen, Chem. Commun., 1999, 741.
4. P. H. Dussault and K. R. Woller, J. Org. Chem., 1997, 62, 1556.
5. M. J. Baker and P. G. Pringle, J. Chem. Soc., Chem. Commun., 1991, 1292.
6. Easily prepared by a procedure similar to that for 1.
7. K. Fuji, N. Kinoshita and K. Tanaka, Chem. Commun., 1999, 1895.
8. R. Schwesinger and H. Schlemper, Angew. Chem., Int. Ed. Engl., 1987, 26, 1167.
9. T. Pietzonka and D. Seebach, Chem. Ber., 1991, 124, 1837.