School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
J Am Chem Soc. 2010 Dec 8;132(48):17096-8. doi: 10.1021/ja1084207. Epub 2010 Nov 16.
While tertiary boranes undergo efficient protodeboronation with carboxylic acids, tertiary boronic esters do not. Instead, we have discovered that CsF with 1.1 equiv of H2O (on tertiary diarylalkyl boronic esters) or TBAF·3H2O (on tertiary aryldialkyl boronic esters) effect highly efficient protodeboronation of tertiary boronic esters with essentially complete retention of configuration. Furthermore, substituting D2O for H2O provides ready access to deuterium-labeled enantioenriched tertiary alkanes. The methodology has been applied to a short synthesis of the sesquiterpene, (S)-turmerone.
虽然三取代硼烷可与羧酸高效地进行脱硼反应，但三取代硼酸酯却不能。相反，我们发现 CsF 与 1.1 当量的 H2O（用于三芳基烷基硼酸酯）或 TBAF·3H2O（用于三芳基二烷基硼酸酯）可有效地对三取代硼酸酯进行脱硼反应，立体构型基本保持不变。此外，用 D2O 代替 H2O 可以方便地获得氘标记的对映体富集的三级烷烃。该方法已应用于倍半萜（S）-turmerone 的短合成中。
