5-Hydroxypentylammonium acetate as a reusable ionic liquid catalyzes tandem Knoevenagel-phospha-Michael reaction of aldehydes, malononitrile and phosphites

PMDTA-catalyzed multicomponent synthesis and biological activity of 2-amino-4H-chromenes containing a phosphonate or phosphine oxide moiety

A new approach for the preparation of (2-amino-3-cyano-4H-chromen-4-yl)phosphonate derivatives is described. The multicomponent reaction of salicylaldehydes, malononitrile and dialkyl phosphites catalyzed by pentamethyldiethylenetriamine (PMDTA) provided the bicyclic derivatives in high yields. The method developed did not require chromatographic separation, since the products could be recovered from the reaction mixture by simple filtration. Our approach made also possible condensation with secondary phosphine oxides, and this reaction has not been previously reported in the literature. The crystal structures of five derivatives were studied by single-crystal XRD analysis. The in vitro cytotoxicity on different cell lines and the antibacterial activity of the (2-amino-4H-chromen-4-yl)phosphonates synthesized were also explored. According to the IC50 values determined, several derivatives showed moderate or promising activity against mouse fibroblast (NIH/3T3) and human promyelocytic leukemia (HL-60) cells. Furthermore, three (2-amino-3-cyano-4H-chromen-4-yl)phosphine oxides were active against selected Gram-positive bacteria.

Synthesis of organophosphorus compounds using ionic liquids

Organophosphorus chemistry was developed in the last decade by promoting the synthesis reactions using ionic liquids either as solvent or catalyst. Ionic liquids (ILs), the so-called “green solvents”, have gained interest in the synthesis of organophosphorus compounds as alternatives to flammable and toxic organic solvents and catalysts. ILs have beneficial properties because they provide high solubility for many organic and inorganic compounds or metal complexes, have no vapor pressure, and are reusable. Also, in some cases, they can enhance the reactivity of chemical reagents. In this review, we aimed at showing the synthesis of different organophosphorus compounds under green and mild conditions using ILs as reaction media or catalysts, according to a trend developed in the last years. A novel trend is to perform these syntheses under microwave irradiation conditions together with ILs as solvents and catalysts.

Pyridine-grafted graphene oxide: a reusable acid–base bifunctional catalyst for the one-pot synthesis of β-phosphonomalonates via a cascade Knoevenagel–phospha Michael addition reaction in water

Py–GO as a new acid–base bifunctional catalyst was synthesized and employed for the one-pot synthesis of β-phosphonomalonates in water.

Lanthanum(iii) triflate supported on nanomagnetic γ-Fe2O3: a new magnetically recyclable heterogeneous Lewis acid for the one-pot synthesis of β-phosphonomalonates

A new magnetically recyclable heterogeneous Lewis acid was synthesized and used for the one-pot synthesis of β-phosphonomalonates.