Et2Zn as a base: zinc enolate free from other metals significantly enhances the enantiomeric excess in palladium-catalyzed allylic alkylation
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Kaoru Fuji, Naosumi Kinoshita and Kiyoshi Tanaka
Abstract
The enantiomeric excess of palladium-catalyzed allylic alkylations was greatly increased when Et2Zn was used as the base to generate an anion from malonates.
References
M. Kitamura, S. Suga, H. Oka and R. Noyori, J. Am. Chem. Soc., 1998, 120, 9800 CrossRefCAS and references cited therein.
A. Alexakis, J. Vastra and P. Mangeney, Tetrahedron Lett., 1997, 38, 7745 CrossRefCAS and references cited therein.
For a review; see A. B. Charette and J.-F. Marcoux, Synlett, 1995, 1197 Search PubMed.
M. Kimura, Y. Ogawa, M. Shimizu, M. Sueishi, S. Tanaka and Y. Tamaru, Tetrahedron Lett., 1998, 39, 6903 CrossRefCAS and references cited therein.
For example; H. Ozaki Ozaki, A. Hirano and S. Nakahara, Macromol. Chem. Phys., 1995, 196, 2099 Search PubMed.
Zinc enolates of ketones free from other metals were generated from α-iodo ketones or α-iodo aldehydes with Et2Zn; see S. Ito, H. Shinokubo and K. Oshima, Tetrahedron Lett., 1998, 39, 5253 Search PubMed.
M. Hayashi, K. Ono, H. Hoshimi and N. Oguni, Tetrahedron, 1996, 52, 7817 CrossRefCAS.
M. Yamaguchi, T. Shima and T. Yamagishi, Tetrahedron: Asymmetry, 1991, 2, 663 CrossRef.
Et2Zn was successfully used in the asymmetric Horner–Wadsworth–Emmons reaction. K. Tanaka, T. Watanabe, K. Shimamoto, P. Sahakitpichan and K. Fuji, Tetrahedron Lett., 1999, 40, 6599 Search PubMed.
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