An Expeditious and Green Approach for the Synthesis of 2-Amino-4h-Chromenes Using a Catalyst of Natural Origin

Abstract

A highly efficient three-component one step system for the synthesis of 2-amino-4H-chromens is developed. Excellent yields were obtained simply by mixing malononitrile, aromatic aldehyde and α-napthol in lemon juice as a catalyst of natural origin and solvent, avoiding using hazardous organic solvents. The main advantages of this method are its green method character, short reaction time and simple workup procedures and the lack of using any metal containing catalysts. * Corresponding Authors

From traditional to greener alternatives: potential of plant resources as a biotransformation tool in organic synthesis

“…7) using lemon peel and baker's yeast as bio-agents. 27,62,63 Later, using bio-resources like coconut water, bakers' yeast and bilimbi fruit extract, two more biologically active 2-amino-4pyran derivatives 32 & 34 were synthesised 26,27,63,64,65 (Fig. 7).…”

Copper Schiff base complex immobilized on magnetic graphene oxide: Efficient heterogeneous nanocatalyst for treating environmental pollutants and synthesis of chromenes

“…To examine the efficiency of the synthesized catalytic system, its catalytic activity in the reaction of different aldehydes, malononitrile, and 1-naphthol for the synthesis of 2-amino-4H-chromene derivatives was compared with other reported ones; the results are shown in Table 3. [17,[52][53][54][55][56][57][58][59] As seen, simple workup of the synthesized catalyst, its nontoxicity and suitable needed amount, the short reaction time, use of green solvents, low temperature, low price, high stability, and high yield are its main advantages in comparison with the others. Environmental pollution is one of the major challenges for modern society.…”

Valorisation of Fruits, their Juices and Residues into Valuable (Nano)materials for Applications in Chemical Catalysis and Environment

“…Rec. 2020, 20, 1338 -1393 mens via an efficient single-step reaction (Scheme 17) [109] with advantages such as shorter reaction time, greener approach with simple workup procedures in a metal-free catalysis. [110] good-to-excellent yields were achieved when esters 1 a-o used through 24 h; but the best yield was attained for 5 a (97 %) from 3 and 1 a.…”

“…In 2018, Ingle and co‐workers used lemon juice as an organic catalyst and solvent to synthesize 2‐amino‐4 H ‐chromens via an efficient single‐step reaction (Scheme 17) [109] with advantages such as shorter reaction time, greener approach with simple workup procedures in a metal‐free catalysis.…”