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
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.
In the title compound, C16H12O2, the six-membered ring adopts a half-chair conformation and the fused five-membered ring is in a conformation between flattened sofa and half-chair. The propargyl residue is twisted diagonally towards the five-membered ring. In the solid state, the propargyl group is involved in C-H ... O intermolecular hydrogen bonds to form an infinite one-dimensional chain along the a axis.
Enantioselective synthesis of the gibbane framework
The triketone (1), possessing a mirror plane of symmetry, prepared from indane-1,3-dione, has been transformed into the gibbaneframeworkenantioselectively by asymmetric aldolization catalysed by L-proline.