Ionic Liquids and Water as “Green” Solvents in Organophosphorus Synthesis

Synthesis of 2-(arylamino)ethyl phosphonic acids via the aza-Michael addition on diethyl vinylphosphonate

“…The use of dry alcoholic solvents like EtOH or MeOH allowed to improve the reaction conditions (Table 1, entries 6 and 8), nevertheless, despite their polar character better results were obtained by adding water (Table 1, entry 7). But none of these conditions compete with reaction in water that was completed within only 45 min at 100 C in high chemical yield ( Having demonstrated that water is the solvent of choice to perform this reaction (agreeing with reported literature 3,27,33,34 ), we next evaluated the aza-Michael additions of primary and secondary amines, focussing particularly on those bearing an aromatic group, to diethyl vinylphosphonate in presence of water (Scheme 2). To begin with, amines 1aei, namely, benzylamine 1a, N-benzylmethylamine 1b, N-naphthylmethylamine 1c, dibenzylamine 1d, 1,2,3,4-tetrahydroisoquinoline 1e, phenethylamine 1f, N-methylethylenediamine 1g, diisopropylamine 1h, and dipropylamine 1i were selected and evaluated in this reaction (see Table 2).…”

Synthesis of α‐aminophosphonates from α‐hydroxyphosphonates; a theoretical study

“…The basic method for the synthesis of α‐hydroxyphosphonates is the Pudovik reaction involving direct phosphonylation of carbonyl compounds by the addition of dialkyl phosphites . Base‐ or acid‐catalyzed variations were also described .…”

Mechanism and kinetics of Horner–Wadsworth–Emmons reaction in liquid–liquid phase-transfer catalytic system

“…Even though the principal advantage consists in easy work-up procedure (the formed phosphates can easily be removed by water), HWE reaction is known to proceed at a slow reaction rate, high energy consumption and difficult solvent recycle [3]. Hence, the green synthetic method have been one topic of researches on HWE reaction [4].…”