The Effects of a Remote Stereogenic Center in the Lewis Base Catalyzed Aldol Additions of Chiral Trichlorosilyl Enolates
作者:Scott E. Denmark、Shinji Fujimori
DOI:10.1021/ol026594n
日期:2002.10.1
Chiral trichlorosilylenolates bearing a remote stereogenic center were employed in the phosphoramide-catalyzed aldol reaction. The additions of the methyl ketoneenolates proceeded with only moderate diastereoselectivities. The addition of the Z-enolate to various aldehydes selectively produced the syn relative diastereomers. In both cases, the effect of the beta-silyloxy stereogenic center was modest
Lewis Base Catalyzed Aldol Additions of Chiral Trichlorosilyl Enolates and Silyl Enol Ethers
作者:Scott E. Denmark、Shinji Fujimori、Son M. Pham
DOI:10.1021/jo051930+
日期:2005.12.1
diastereodifferentiation in chiral Lewis base catalyzed aldoladditions using chiral enoxysilanes derived from lactate, 3-hydroxyisobutyrate, and 3-hydroxybutyrate have been investigated. Trichlorosilylenolates derived from the chiral methyl and ethyl ketones were subjected to aldolization in the presence of phosphoramides, and the intrinsic selectivity of these enolates and the external stereoinduction