A Relay Ring-Closing Metathesis Synthesis of Dihydrooxasilines, Precursors of (<i>Z</i>)-Iodo Olefins
作者:Qiuzhe Xie、Richard W. Denton、Kathlyn A. Parker
DOI:10.1021/ol802063h
日期:2008.12.4
A convenient Grubbs II metathesis provides dihydrooxasilines by relay RCM (RRCM). Dihydrooxasilines undergo ring opening to give Z-vinyl silanes. These can then be converted to Z-vinyl iodides. This sequence provides a short, high yield, and convenientroute to trisubstituted Z-vinyl iodides, useful intermediates for the preparation of polypropionate antibiotics.
方便的 Grubbs II 复分解通过中继 RCM (RRCM) 提供二氢恶唑啉。二氢恶唑啉开环得到 Z-乙烯基硅烷。然后可以将它们转化为 Z-乙烯基碘化物。该序列为三取代的 Z-乙烯基碘(用于制备聚丙酸酯抗生素的有用中间体)提供了一条短、产率高且方便的途径。
Stereoselective Synthesis of Silacyclohexanols by Silicon Tethered Type II Ene Cyclisation
作者:Jeremy Robertson、Garry O'Connor、Tsarina Sardharwala、Donald S. Middleton
DOI:10.1016/s0040-4020(00)00737-7
日期:2000.10
silane precursors for intramolecular ene reaction were prepared either by sequential organometallic substitution of appropriate silyl halides or by ring opening of oxasilacyclopentanes with 2-propenyllithium. The oxasilacyclopentane intermediates were prepared by free-radicalcyclisation, intramolecular hydrosilylation, or intramolecular Diels–Alder reaction. Treatment of the ene precursors with methylaluminium