An Expedient and Stereoselective Synthesis of Alkenyl Nonaflates from Silyl Enol Ethers: Optimization, Scope and Limitations
作者:Ilya M. Lyapkalo、Matthias Webel、Hans-Ulrich Reißig
DOI:10.1002/1099-0690(200203)2002:6<1015::aid-ejoc1015>3.0.co;2-k
日期:2002.3
catalysts for this process. The reaction allows the synthesis of a wide variety of cyclic and acyclic alkenyl nonaflates 3 in good to excellent yields. For E/Z isomeric alkenes the configuration of the double bond is essentially retained. Remarkably, enolates derived from methyl ketones also provide C-sulfonylation products 4 as a side product; the desired alkenyl nonaflates 3l and 3m could, however, be prepared
已优化甲硅烷基烯醇醚 1 和九氟丁烷磺酰氟 (NfF) 之间的氟化物催化反应,从而可以方便地合成相应的烯基九氟甲磺酸酯 3。四正丁基氟化铵,用分子筛或氟化钾干燥,以及在二苯并 18-crown-6 存在下的氟化钾是该过程的最佳和最实用的催化剂。该反应允许以良好到极好的产率合成各种环状和无环烯基壬二酸酯 3。对于 E/Z 异构烯烃,基本上保留了双键的构型。值得注意的是,衍生自甲基酮的烯醇也提供 C-磺酰化产物 4 作为副产物;然而,可以通过进一步优化以良好的产率制备所需的烯基壬二酸酯 3l 和 3m。