10088-45-6Relevant articles and documents
Wet and dry processes for the selective transformation of phosphonates to phosphonic acids catalyzed by br?nsted acids
Li, Chunya,Saga, Yuta,Onozawa, Shun-Ya,Kobayashi, Shu,Sato, Kazuhiko,Fukaya, Norihisa,Han, Li-Biao
, p. 14411 - 14419 (2020)
A "wet"process and two "dry"processes for converting phosphonate esters to phosphonic acids catalyzed by a Bronsted acid have been developed. Thus, in the presence of water, a range of alkyl-, alkenyl-, and aryl-substituted phosphonates can be generally hydrolyzed to the corresponding phosphonic acids in good yields catalyzed by trifluoromethyl sulfonic acid (TfOH) at 140 °C (the wet process). On the other hand, with specific substituents of the phosphonate esters, the conversion to the corresponding phosphonic acids can be achieved under milder conditions in the absence of water (the dry process). Thus, the conversion of dibenzyl phosphonates to the corresponding phosphonic acids took place smoothly at 80 °C in toluene or benzene in high yields. Moreover, selective conversion of benzyl phosphonates RP(O)(OR′)(OBn) to the corresponding mono phosphonic acids RP(O)(OR′)(OH) can also be achieved under the reaction conditions. The dealkylation via the generation of isobutene of ditert- butyl phosphonate, and the related catalysis by TfOH took place even at room temperature to give the corresponding phosphonic acids in good to high yields. Nafion also shows high catalytic activity for these reactions. By using Nafion as the catalyst, phosphonic acids could be easily prepared on a large scale via a simple process.
Competition of methanol and tert-butanol in nucleophilic substitution at phosphorus atom
Cieplucha, Agnieszka,Jankowski, Stefan
, p. 1448 - 1453 (2009)
2,3-Oxaphosphabicyclo[2.2.2]octene 1 reacts with alcohols simultaneously according to two competitive mechanisms: bimolecular addition-elimination and unimolecular elimination-addition with the intermediacy of metaphosphonate Ph-PO2 (2). In 1,2-dichloroet
Double role of the hydroxy group of phosphoryl in palladium(II)-catalyzed ortho -olefination: A combined experimental and theoretical investigation
Liu, Liu Leo,Yuan, Hang,Fu, Tingting,Wang, Tao,Gao, Xiang,Zeng, Zhiping,Zhu, Jun,Zhao, Yufen
, p. 80 - 87 (2014/01/17)
Density functional theory calculations have been carried out on Pd-catalyzed phosphoryl-directed ortho-olefination to probe the origin of the significant reactivity difference between methyl hydrogen benzylphosphonates and dimethyl benzylphosphonates. The overall catalytic cycle is found to include four basic steps: C-H bond activation, transmetalation, reductive elimination, and recycling of catalyst, each of which is constituted from different steps. Our calculations reveal that the hydroxy group of phosphoryl plays a crucial role almost in all steps, which can not only stabilize the intermediates and transition states by intramolecular hydrogen bonds but also act as a proton donor so that the η1-CH3COO- ligand could be protonated to form a neutral acetic acid for easy removal. These findings explain why only the methyl hydrogen benzylphosphonates and methyl hydrogen phenylphosphates were found to be suitable reaction partners. Our mechanistic findings are further supported by theoretical prediction of Pd-catalyzed ortho-olefination using methyl hydrogen phenylphosphonate, which is verified by experimental observations that the desired product was formed in a moderate yield.
