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...

Monofunctional (Dimethylaminol)silane as Silylating Agent.

New, practical approaches for the synthesis of α-amino (2-alkynylphenyl)-methylphosphonates and 1,2-dihydroisoquinolin-1-ylphosphonates were developed. By the propylphosphonic anhydride (T3P®)-mediated Kabachnik–Fields reaction of 2-alkynylbenzaldehydes, aniline, and dialkyl phosphites, α-amino (2-alkynylphenyl)-methylphosphonates were obtained selectively in high yields. The method developed is a simple operation and did not require a chromatographic separation since the products could be isolated from the reaction mixture by a simple extraction. At the same time, 2,3-disubstituted-1,2-dihydroisoquinolin-1-ylphosphonates could be prepared effectively from the same kinds of starting materials (2-alkynylbenzaldehydes, aniline, and dialkyl phosphites) at 60 °C in a short reaction time by changing the catalyst for CuCl. Therefore, it was proved that the catalyst system applied played a crucial role with respect to the reaction outcome.

Organophosphorus compounds play an important role in the medicinal-or agricultural industry, and in the human body as well. Over the last years, heterocyclic phosphonates have received an intensively growing interest due to their potential biological activity. An efficient tool for the preparation of such derivatives is their synthesis via multicomponent reactions. These transformations possess several criteria of an "ideal synthesis", such as the high atom economy, the fast and simple accomplishment, the energy efficiency and the environmentally friendliness. A number of heterocyclic phosphonates were prepared by us utilizing multicomponent syntheses. In this proceeding, the synthesis of the diethyl (2-amino-3-cyano-4H-chromen-4-yl)phosphonate by the condensation of salicylaldehyde, malononitrile and diethyl phosphite is briefly introduced. The reaction was optimized in respect of the catalyst type, the catalyst amount, the reaction time, and the temperature.

An efficient, practical, and green approach for the synthesis of α-aminophosphonates incorporating a chromone moiety by the one-pot Kabachnik-Fields reaction has been developed. The three-component reactions of 3-formylchromones, primary amines and dialkyl phosphites was carried out in short reaction times in the absence of any catalyst or solvent under microwave irradiation. The method developed did not require column chromatographic separation since the products could be recovered from the reaction mixture by simple filtration. The method developed could be applied to a range of primary amines and dialkyl phosphites, which confirmed the large scope and functional-group tolerance.