Novel Synthesis of Phosphinates by the Microwave-Assisted Esterification of Phosphinic Acids

Environmentally Friendly Chemistry with Organophosphorus Syntheses in Focus

“…Similar experiments were carried out for the synthesis of risedronic acid (45b) applying pyridylacetic acid (46) and phosphorus trichloride (Scheme 20.) [91].…”

“…A series of phosphinic acids underwent efficient esterification using alcohols with longer chain at around 200°C on MW irradiation (Scheme 7) [43,[46][47][48]. The esterification of cyclic phosphinic acids, such as 1-hydroxy-3-phospholene oxides (8a and 8b), 1-hydroxyphospholane oxides (8c and 8d) and 1-hydroxy-1,2,3,4,5,6-hexahydrophosphinine oxide (8e) was carried out in a closed vessel to afford the phosphinates (9a-e) in acceptable to excellent yields [43,[46][47][48]. The method elaborated by us is of a more general value.…”

Mikor igazán érdemes mikrohullámú körülmények között lejátszatni egy szerves kémiai reakciót?

“…27 Mi azonban azt tapasztaltuk, hogy 200-220 °C-on -az alkoholokat 15-szeres feleslegben alkalmazva -MW besugárzásra a különféle foszfinsavak észteresíthetõk. [28][29][30] Modellreakcióként válasszuk az 1-hidroxi-3-metil-3-foszfolén-1-oxid butanollal megvalósított észteresítését. 200 °C-on végzett 3 órás MW fûtés után 58%-os konverzióval képzõdött az 1-butoxi-foszfolén-oxid.…”

The Use of MW in Organophosphorus Chemistry

“…We have recently found that a series of phosphinic acids underwent direct esterification with longer chain alcohols on MW irradiation at around 170-220°C [21]. The first example was the esterification of phenyl-H-phosphinic acid (8) at 170°C to give the corresponding phosphinates (9) in yields of 73-90 % (Scheme 3.4).…”