1809-20-7Relevant articles and documents
Goodell,Yoke
, p. 2461 (1969)
Way to Enforce Selectivity via Steric Hindrance: Improvement of Am(III)/Eu(III) Solvent Extraction by Loaded Diphosphonic Acid Esters
Matveev, Petr I.,Huang, Pin-Wen,Kirsanova, Anna A.,Ananyev, Ivan V.,Sumyanova, Tsagana B.,Kharcheva, Anastasia V.,Khvorostinin, Evgenii Yu.,Petrov, Vladimir G.,Shi, Wei-Qun,Kalmykov, Stepan N.,Borisova, Nataliya E.
, p. 14563 - 14581 (2021/10/12)
Hybrid donor extractants are a promising class of compounds for the separation of trivalent actinides and lanthanides. Here, we investigated a series of sterically loaded diphosphonate ligands based on bipyridine (BiPy-PO-iPr and BiPy-PO-cHex) and phenant
Copper-Catalyzed C?P Cross-Coupling of (Cyclo)alkenyl/Aryl Bromides and Secondary Phosphine Oxides with in situ Halogen Exchange
Stankevi?, Marek,Wo?nicki, Pawe?
supporting information, p. 3484 - 3491 (2021/07/22)
An efficient protocol for concurrent tandem halogen exchange/C?P cross-coupling of cycloalkenyl bromides and secondary phosphine oxides has been developed. The catalytic system is based on cheap and air-stable copper(I) iodide as the precatalyst, commercially available N,N’-dimethylethylenediamine as the ligand, and Cs2CO3 or K2CO3 as the base. The use of sodium iodide as an additive reduces the excessive use of organic bromides to near-stoichiometric by promoting the in situ transformation to the corresponding iodides. Diarylphosphine oxides undergo cycloalkenylation with 35–99 % yields and dicyclohexylphosphine oxide with 30–53 % yields. In the case of acyclic alkenyl bromides the cross-coupling products undergo conjugate addition of diphenylphosphine oxide and satisfying yields are observed only for internal olefins. In the case of aryl bromides satisfying yields (43–72 %) are observed only for sterically unhindered arenes or arenes possessing an ortho-directing group. Cycloalkenylphosphine oxides prepared in the cross-coupling reaction undergo base-catalyzed and base-promoted conjugate addition to give bis(phosphinoyl)cycloalkanes.
Water determines the products: An unexpected Br?nsted acid-catalyzed PO-R cleavage of P(iii) esters selectively producing P(O)-H and P(O)-R compounds
Li, Chunya,Wang, Qi,Zhang, Jian-Qiu,Ye, Jingjing,Xie, Ju,Xu, Qing,Han, Li-Biao
supporting information, p. 2916 - 2922 (2019/06/18)
Water is found able to determine the selectivity of Br?nsted acid-catalyzed C-O cleavage reactions of trialkyl phosphites: with water, the reaction quickly takes place at room temperature to afford quantitative yields of H-phosphonates; without water, the reaction selectively affords alkylphosphonates in high yields, providing a novel halide-free alternative to the famous Michaelis-Arbuzov reaction. This method is general as it can be readily extended to phosphonites and phosphinites and a large scale reaction with much lower loading of the catalyst, enabling a simple, efficient, and practical preparation of the corresponding organophosphorus compounds. Experimental findings in control reactions and substrate extension as well as preliminary theoretical calculation of the possible transition states all suggest that the monomolecular mechanism is preferred.
