A Rapid, Efficient and Green Method for Synthesis of 3,3'-Arylmethylene-bis-4-hydroxycoumarins without Use of any Solvent, Catalyst or Solid Surface

Abstract: A rapid, efficient and green methodology has been developed for the synthesis of 3,3'-arylmethylene-bis-4-hydroxycoumarins by microwave assisted condensation of aromatic aldehydes and 4-hydroxycoumarin without use of any solvent, catalyst or solid surface

Synthesis of several types of 2,8-dioxabicyclo[3.3.1]nonanes using amberlyst-15 as an efficient recyclable heterogeneous catalyst

<p>A facile synthesis of 2,8-dioxabicyclo[3.3.1]nonane derivatives starting from simple molecules like 2-hydroxychalcones as one component and dimedone, 4-hydroxycoumarin, 2-hydroxynaphthoquinone, 2-naphthol or 1-naphthol, as the other has been achieved by use of amberlyst-15, a sulfonated polystyrene resin, as a recyclable heterogeneous catalyst. The methodology involves a domino sequence of Michael addition and two-stage cyclisation.</p