Anti-Selective Aldol Reactions of Pentafluorosulfanylacetic Acid Esters with Aldehydes Mediated by Dicyclohexylchloroborane
详细信息 查看全文
- 作者：Florian W. Friese ; Anna-Lena Dreier ; Andrej V. Matsnev ; Constantin G. Daniliuc ; Joseph S. Thrasher ; Günter Haufe
- 刊名：Organic Letters
- 出版年：2016
- 出版时间：March 4, 2016
- 年：2016
- 卷：18
- 期：5
- 页码：1012-1015
- 全文大小：308K
- ISSN：1523-7052
文摘
Aldol reactions of pentafluorosulfanyl (SF5)-substituted acetic acid esters with both aromatic and aliphatic aldehydes proceeded with excellent anti-diastereoselectivity and good to high yields using dicyclohexylchloroborane/triethylamine. This methodology enabled the synthesis of hitherto unknown α-SF5-β-hydroxy esters. Using a norephedrine-based auxiliary, high asymmetric induction was observed. The stereochemistry of products was assigned by NMR spectroscopy and proved by X-ray diffraction analysis. The intermediate enolate was identified as a highly unstable species.