A new one-pot synthesis of α-amino phosphonates catalyzed by H3PW12O40

An eco-friendly procedure for the efficient synthesis of diethyl α-aminophosphonates in aqueous media using natural acids as a catalyst

“…This problem was solved either by co-use of catalyst with dehydrating agent or by application of catalysts being stable in water, as, for example, Brønsted acids such as heteropoly acid, guanidine hydrochloride and supported oxalic acid [51][52][53]. These methods involve either long reaction times, low yields of the products, required stoichiometric amount of reagents, use of additives or expensive catalysts.…”

An eco-friendly procedure for the efficient synthesis of dialkyl α-aminophosphonates in aqueous media

“…Generation of water during the course of the reaction can decompose or deactivate these Lewis acids [5,6]. This drawback has been overcome by some recent methods using lanthanide triflates/magnesium sulfate [7], InCl 3 [8], TaCl 5 -SiO 2 [9], ZrCl 4 [10], Sc(DS) 3 [11], H 3 PW 12 O 40 [12], BiNO 3 Á 5H 2 O [13], Mg(ClO 4 ) 2 [14,15] and b-cyclodextrine [16]. However, these methods involve either long reaction times, low yields of the products, required stoichiometric amount of reagents, use of additives or expensive catalysts.…”

One‐pot synthesis of α‐aminophosphonates catalyzed by boric acid at room temperature

“…One-pot threecomponent condensation of aldehydes, amines, and dimethylphosphite or trimethylphosphite is the most convenient method for the preparation of these compounds. In this context, some methods and catalysts have been reported such as LiClO 4 [8], oxalic acid [9], TaCl 5 -SiO 2 [10], β-cyclodextrin [11], Mg(ClO 4 ) 2 [12], InCl 3 [13], SmI 2 [14], amberlite-IR 120 [15], H 3 PW 12 O 40 [16], ionic liquid [17], FeCl 3 [18], and silica sulfuric acid [19]. However, these methodologies show varying degrees of success as well as limitations due to use of toxic organic solvents, expensive catalyst, prolonged reaction times, the requirement of special apparatus, or harsh reaction conditions.…”