Optically active tricarbonyl[.eta.6-o-(trimethylsilyl)benzaldehyde]chromium(0) complexes in organic synthesis: a highly anti-selective asymmetric aldol reaction with O-silyl ketene O,S-acetals
摘要:
Treatment of optically pure (+)-tricarbonyl[o-(trimethylsilyl)benzaldehyde]chromium(0), (+)-1, with O-silyl ketene O,S-acetals 4c-f afforded, after decomplexation, the (-)-anti-aldol products (-)-5c-f, while an antipode, (-)-1, provided the (+)-anti ones (+)-5c-f. Optical purity of these aldol products were determined to be in a range of 92 to > 98% ee. The absolute configuration was established by an X-ray crystallographic analysis.
New chiral tricarbonyl(η6-arene)chromium(0) complexes: synthesis and preliminary application in asymmetric catalysis
作者:Carsten Bolm、Kilian Muñiz、Christian Ganter
DOI:10.1039/a804390f
日期:——
synthesis of new enantiomericallypure tricarbonyl(η6-arene)chromium(0) complexes having both planar and central chirality is reported. The procedure for their preparation involves a directed ortho-lithiation as the key step using (S)-2-methoxymethylpyrrolidine (SMP) as a suitable anchor group. The absolute configuration of the newly generated element of planarchirality was determined via chemical correlation