Cu(OAc)2 catalyzed ultrasound assisted rapid synthesis of isocoumarin derivatives bearing 3-oxobutyl moiety at C-4 position

A rapid synthesis of isocoumarins has been achieved via the Cu-catalysed cascade reaction involving tandem intramolecular cyclization followed by olefin addition under ultrasound irradiation. The methodology involved one-pot reaction of 2-alkynylbenzoate esters with methyl vinyl ketone in the presence of Cu(OAc)(2) in aqueous DMF to afford a range of isocoumarin derivatives bearing 3-oxobutyl moiety at C-4 position. The use of inexpensive, stable and environmentally friendly catalyst along with aqueous media, shorter reaction time and simple operational procedure are the key advantages of this Pd-free methodology. 2009 Elsevier Ltd. All rights reserved. (C) 2022 Elsevier B.V. All rights reserved.