Synthesis of Phosphinoferrocenyloxazolines. New Ligands for Asymmetric Catalysis

详细信息    查看全文

• 作者：Richards ; Christopher J. ; Mulvaney ; Andrew W.
• 刊名：Tetrahedron: Asymmetry
• 出版年：1996
• 出版时间：May, 1996
• 年：1996
• 卷：7
• 期：5
• 页码：1419-1430
• 全文大小：692 K

文摘

Condensation of β-hydroxy alcohols with ferrocenyl chloride gave the corresponding amides which were dehydrated to give ferrocenyl oxazolines in good overall yield. Subsequent lithiation with n-BuLi in the presence of TMEDA and addition of PPh₂Cl led to the isolation of (S)-(S)-ⁱPr-phosferrox and (S)-(S)-Me-phosferrox ligands 1 and2 . Their corresponding diastereoisomers, (S)-(R)-ⁱPr-phosferrox and (S)-(R)-Me-phosferrox 3 and 4 were obtained via the intermediacy of removable trimethylsilyl blocking groups. The CD spectra of 1 - 4 and their parent ferrocenyl oxazolines 9 and 10 were obtained.