efficient and practical protocol for the synthesis of both Wieland–Miescher ketone and Hajos–Parrishketone as well as their analogues. The reaction can be conducted in gram scale with 1% mol catalyst loading producing high enantioselectivity (up to 96% ee) and excellent yields (up to 98%). This procedure represents one of the most efficient methods for the synthesis of these versatile chiral building blocks
Desymmetrisation of <i>meso</i>-diones promoted by a highly recyclable polymer-supported chiral phosphoric acid catalyst
作者:Lidia Clot-Almenara、Carles Rodríguez-Escrich、Miquel A. Pericàs
DOI:10.1039/c7ra13471a
日期:——
A polystyrene-supported BINOL-derived chiral phosphoric acid has been applied to the desymmetrisation of meso-diones to produce enantioenriched cyclohexenones. The catalytic resin has proven highly active and robust, giving rise to Hajos–Parrish or Wieland–Miescher type products in good yields and enantioselectivities, while allowing for extended recycling.
Chiral effectiveness: The title transformation is applicable to a wide variety of substrates to give chiralcyclohexenones in high yields and with excellent enantioselectivity (see scheme). To clarify the origin of the enantioselectivity ONIOM calculations were carried out