Mild Ring‐Opening 1, 3‐Hydroborations of Non‐Activated Cyclopropanes. (21st November 2018) - Wang, Di
Abstract: The Brown hydroboration reaction, first reported in 1957, is the addition of B−H across an olefin in an anti‐Markovnikov fashion. Here, we solved a long‐standing problem on mild 1, 3‐hydroborations of non‐activated cyclopropanes. A three‐component system including cyclopropanes, boron halides, and hydrosilanes has been developed for borylative ring‐opening of cyclopropanes following the anti‐Markovnikov rule, under mild reaction conditions. Density functional theory (M06‐2X) calculations show that the preferred pathway involves a cationic boron intermediate which is quenched by hydride transfer from the silane. Abstract : Ein mildes Dreikomponentensystem wurde für die Herstellung von Alkylboronsäureestern durch ringöffnende 1, 3‐Hydroborierungen nichtaktivierter Cyclopropane entwickelt. Die Methode ist mit funktionellen Gruppen gut kompatibel und eignet sich für borylierende Cyclopropan‐Ringöffnungen in komplexen Molekülen.