53269-48-0Relevant articles and documents
Exploring an Umpolung strategy for quaternization of phosphorus
Vetter, Anna C.,Nikitin, Kirill,Gilheany, Declan G.
, p. 339 - 342 (2019/03/07)
We propose a new, potentially widely-applicable, Umpolung approach for the synthesis of quaternary phosphonium salts R3PR1 X (X = Cl, Br) from phosphine oxides R3PO. The new organic group R1 is introduced via nucleophilic attack on an intermediate halophosphonium salt using a Grignard reagent R1MgX and replaces the traditional phosphine quaternization approach. Consequently, the new method does not suffer from the limited availability of many parent phosphines and is much faster than standard quaternization.
Physical and electrochemical properties of room-temperature dicyanamide ionic liquids based on quaternary phosphonium cations
Tsunashima, Katsuhiko,Kodama, Shun,Sugiya, Masashi,Kunugi, Yoshihito
experimental part, p. 762 - 766 (2011/03/20)
The physicochemical and electrochemical properties of room temperature ionic liquids based on quaternary phosphonium cations together with a dicyanamide anion are presented in this report. The most dicyanamide-based phosphonium ionic liquids prepared were hydrophilic, except ionic liquids containing a long alkyl chain in the phosohonium cation. It was found that asymmetric phosphonium cations gave low-melting salts in combination with a dicyanamide anion. The dicyanamide-based phosphonium ionic liquids exhibited relatively low viscosities and high conductivities when compared to those of the corresponding ammonium ionic liquids. Particularly, the ionic liquids containing a methoxy group in the phosphonium cations indicated very low viscosities. Comparatively good electrochemical stability of the dicyanamide-based phosphonium ionic liquids was confirmed by voltammetric measurements. The thermogravimetric analysis suggested that the dicyanamide-based phosphonium ionic liquids showed higher thermal stability than those of the corresponding ammonium ionic liquids, indicating an improving effect of the phosphonium cations on the thermal stability.
The reaction of primary aromatic amines with alkylene carbonates for the selective synthesis of bis-N-(2-hydroxy)alkylanilines: The catalytic effect of phosphonium-based ionic liquids
Selva, Maurizio,Fabris, Massimo,Lucchini, Vittorio,Perosa, Alvise,Noe, Marco
experimental part, p. 5187 - 5198 (2010/12/25)
At T ≥ 140 °C, different primary aromatic amines (pX-C 6H4NH2; X = H, OCH3, CH3, Cl) react with both ethylene- and propylene-carbonates to yield a chemoselective N-alkylation process: bis-N-(2-hydroxyalkyl)anilines [pX-C 6H4N(CH2CH(R)OH)2; R = H, CH 3] are the major products and the competitive formation of carbamates is substantially ruled out. At 140 °C, under solventless conditions, the model reaction of aniline with ethylene carbonate goes to completion by simply mixing stoichiometric amounts of the reagents. However, a class of phosphonium ionic liquids (PILs) such as tetraalkylphosphonium halides and tosylates turn out to be active organocatalysts for both aniline and other primary aromatic amines. A kinetic analysis monitored by 13C NMR spectroscopy, shows that bromide exchanged PILs are the most efficient systems, able to impart a more than 8-fold acceleration to the reaction. The reactions of propylene carbonate take place at a higher temperature than those of ethylene carbonate, and only in the presence of PIL catalysts. A mechanism based on the Lewis acidity of tetraalkylphosphonium cations and the nucleophilicity of halide anions has been proposed to account for both the reaction chemoselectivity and the function of the catalysts.
Dichotomous reactivity in the reaction of triethyl- and triphenylphosphane HBr salts with dimethyl acetals: A novel entry to α-alkoxy-functionalized ylides and general synthesis of vinyl ethers and alkoxy dienes
Das, Priyabrata,McNulty, James
supporting information; experimental part, p. 3587 - 3591 (2010/09/05)
The discovery of dichotomous reactivity in the reaction of trialkyl- vs. triphenylphosphane HBr salts with acetals allows entry to functionalized α-methoxy phosphonium salts and a novel process for tertiary phosphane methylation. The new protocol opens a general entry to the synthesis of vinyl ethers and differentially substituted 1,3-dienes via Wittig reactions of the functionalized ylides derived from the α-methoxy phosphonium salts.
