FeCl₃-Catalyzed Cascade Reaction: An Efficient Approach to Functionalized Coumarin Derivatives

Abstract

An efficient and environmentally benign synthesis of 3-substituted or 3,4-disubstituted coumarins was accomplished via iron(III) chloride-catalyzed cascade reactions of salicylaldehydes and activated methylene compounds. The reaction preceded cleanly under mild reaction conditions to provide the desired coumarin derivatives in good to excellent yields.

Synthesis and Biological Properties of Coumarin Derivatives. A Review

“…Under ultrasonic irradiation, Sripathi and Logeewari [32] reported the synthesis of 3‐phenylcoumarins from salicylaldehydes and phenylacetyl chloride using K 2 CO 3 in THF, Scheme 5.…”

Recent Advances in the Synthesis of Coumarin Derivatives from Different Starting Materials

“…Yields obtained with ethyl 2-cyanoacetate were higher than with malonoitrile. Synthesis of 3-substituted coumarins catalyzed by iron(III) chloride was reported by He et al [34]. Model reaction of salicylaldehydes and malononitrile was performed in order to determine the best reaction conditions.…”

“…Most of the extracted coumarins have biological activity and therefore coumarin derivatives are increasingly being synthesized, since their extraction from plants is time-consuming and unprofitable (too many operation steps to the final product) [32]. Coumarins could be synthesized with many different methods like Perkin reaction, Knoevenagel condensation, Pechmann condensation, Wittig reaction, Baylis-Hillman reaction, Claisen rearrangement and Vilsmeier-Haack and Suzuki cross-coupling reaction [33,34]. Many authors have published researches exploring the medicinal properties of coumarins [4,6,12,[35][36][37].…”

Palladium‐catalyzed cross‐coupling reactions of coumarin derivatives: An overview

“…[ 31–33 ] Most of these reactions are multistep and time‐consuming, but this has been solved by the introduction of metal‐catalyzed intermolecular or intramolecular coupling reactions. Owing to the great importance of this small, but useful, moiety, much attention has been given to the development of synthetic methods for substituted coumarins using transition‐metal catalysts such as palladium, [ 34 ] iron, [ 35 ] gold, [ 36 ] silver, [ 37 ] copper, [ 38 ] platinum, [ 39 ] nickel, [ 40 ] cobalt, [ 41 ] rhodium, [ 42 ] gallium, [ 43 ] and zinc. [ 44 ] Recently, a review based on the efficient synthetic methods for 4‐arylcoumarins has been reported.…”