Search

Chromenes represent a pivotal molecular structure found in a diverse range of biologically active compounds. Specifically, derivatives of 2‐amino‐3‐cyano‐4H‐chromene have demonstrated pharmacological applications, displaying potential antioxidant and anticancer activities. This has heightened interest in the exploration of new and more efficient methods for their synthesis. In recent years, few examples have emerged, focusing on the organocatalytic and enantioselective synthesis of 2‐amino‐3‐cyano‐4H‐chromene derivatives, although the overall number of works to date is limited. In this study, we present the results of the synthesis of 2‐amino‐4H‐chromen‐3,4‐dicarbonitriles through a Michael addition of cyanide to 2‐iminochromenes. To achieve this, we utilized a mild source of cyanide (acetone cyanohydrin), green solvents and catalytic conditions at room temperature, via a multicomponent approach. Furthermore, we initiated the enantioselective study of this process using chiral organocatalysts obtaining promising preliminary results. [ABSTRACT FROM AUTHOR]

The potential of phosphites as nucleophiles for the asymmetric synthesis of chiral chromene derivatives has been overlooked in the literature. Herein, we report a promising approach via asymmetric organocatalyzed phospha‐Michael addition to iminochromenes, using a bifunctional squaramide, which gives access to chromenylphosphonates, an interesting family of bioactive compounds. Our optimized protocol provides very good reactivity, affording yields of up to 95% and with chiral products exhibiting an enantiomeric excess of up to 98%. [ABSTRACT FROM AUTHOR]

Keywords: asymmetric synthesis; phosphite; chromene; organocatalysis; phospha-Michael; biological activity EN asymmetric synthesis phosphite chromene organocatalysis phospha-Michael biological activity 3181 3181 1 10/18/23 20231013 NES 231013 The inside cover picture is an artistic illustration of the bifunctional activation of the phosphite and the iminochromene by a chiral squaramide tattooed on the arm of a chemist. Asymmetric synthesis, phosphite, chromene, organocatalysis, phospha-Michael, biological activity Cover Picture: Asymmetric Organocatalyzed Phospha-Michael Addition for the Direct Synthesis of Biologically Active Chromenylphosphonates (Adv. [Extracted from the article]