- Fragmentation-Related Phosphonylation of Nucleophiles Utilizing P-Alkyl 2,3-oxaphosphabicyclo[2.2.2]octene 3-oxide Precursors
-
New P-alkyl 2,3-oxaphosphabicyclo-[2.2.2]octene 3-oxides were synthesized by the Bayer-Villiger oxidation of the corresponding 7-phosphanorbornene 7-oxides and were used as precursors for reactive alkylmetaphosphonates useful in the phosphonylation of alcohols. This is the first case that the reactivity of the two regioisomers formed by O-insertion was differentiated and that the fragmentation-related phosphonylation leading to phosphonic acid-esters was achieved under microwave-assisted conditions.
- Kovács, Tamara,Fül?p, Laura Szandra,Keglevich, Gy?rgy
-
-
Read Online
- An optimized and scalable synthesis of propylphosphonic anhydride for general use
-
Abstract Propylphosphonic anhydride (T3P) is an effective coupling and dehydrating agent, which has been used for a large number of chemical transformations. An efficient and versatile synthetic method is described to synthesize propylphosphonic anhydride (T3P) in pure form, in an overall yield of 51% in four steps from commercially available diethyl phosphonate.
- Pizova, Hana,Bobal, Pavel
-
supporting information
p. 2014 - 2017
(2015/03/30)
-
- Mild and efficient esterification of alkylphosphonic acids using polymer-bound triphenylphosphine
-
Mild and efficient esterification of alkylphosphonic acids using primary alcohols, iodine, imidazole and polymer-bound triphenylphosphine is developed.
- Purohit, Ajay Kumar,Pardasani, Deepak,Tak, Vijay,Kumar, Ajeet,Jain, Rajeev,Dubey, Devendra Kumar
-
experimental part
p. 3795 - 3797
(2012/09/21)
-
- Highly enantioselective hydrogenation of β-acyloxy and β-acylamino α,β-unsaturated phosphonates catalyzed by rhodium phosphane-phosphite complexes
-
The enantioselective hydrogenation of β-(acyloxy)- and β-(acylamino)vinylphosphonates with rhodium catalysts based on chiral phosphane-phosphite ligands has been studied. In the case of the β-(acyloxy)vinylphosphonates, the reaction also produces an achiral phosphonate resulting from the elimination of the benzoate group. High ligand modularity has led to a highly chemo- and enantioselective catalyst for both types of substrates, which afford a good range of β-acyloxy- and β-acylaminophosphonates with enantioselectivities between 90 and 99% ee. Most interestingly, the configuration of the hydrogenation products indicates the same stereochemical sense for the reduction of both types of substrates, which is opposite to that observed before for α-(acyloxy) vinylphosphonates. This observation has been rationalized by assuming the formation of a β-alkyl intermediate during the catalytic cycle, which also explains the formation of the elimination product in the hydrogenation of the β-(acyloxy)-vinylphosphonates. Copyright
- Chavez, M. Angeles,Vargas, Sergio,Suarez, Andres,Ulvarez, Eleuterio,Pizzano, Antonio
-
experimental part
p. 2775 - 2794
(2011/12/21)
-
- Highly enantioselective hydrogenation of enol ester phosphonates: A versatile procedure for the preparation of chiral β-hydroxyphosphonates
-
A study was conducted to demonstrate a procedure for the preparation of chiral β-hydroxyphosphonates. The reaction sequence was investigated and the validity of the approach was demonstrated. The study also reported an olefin hydrogenation reaction, which gives access to a wide variety of chiral β-hydroxyphosphonates 2, with excellent levels of asymmetric induction, which can be converted into the corresponding alcohols. The application of phosphane-phosphite ligands 4 and 5 were investigated in diverse hydrogenation reactions. Unsaturated phosphonates 1 were chosen as substrates, in an effort to broaden the scope of these catalysts. Investigations were also initiated by the development of a convenient procedure for the synthesis of a set of olefins 1.
- Vargas, Sergio,Suarez, Andres,Alvarez, Eleuterio,Pizzano, Antonio
-
supporting information; experimental part
p. 9856 - 9859
(2009/10/02)
-
- P-Toluenesulfonic acid-Celite as a reagent for synthesis of esters of alkylphosphonic acids under solvent-free conditions
-
The coupling reaction of alkylphosphonic acids and alcohols on the surface of p-toluenesulfonic acid-Celite under mild and solvent-free conditions gave the corresponding phosphonates in excellent yields. This method provides a useful rapid synthesis of phosphonates for use in the unambiguous identification of chemical warfare agents.
- Gupta, Arvind K.,Kumar, Rajesh,Dubey, Devendra K.,Kaushik
-
p. 328 - 331
(2008/02/10)
-
- An efficient method for the esterification of phosphonic and phosphoric acids using silica chloride
-
Silica chloride is used as an effective heterogeneous catalyst for the rapid esterification of alkyl/aryl phosphonic/phosphoric acids to their corresponding alkyl/aryl phosphonates/phosphates under mild conditions with quantitative yields.
- Sathe, Manisha,Gupta, Arvind K.,Kaushik
-
p. 3107 - 3109
(2007/10/03)
-
- Surface-mediated solid phase reactions: A simple, efficient and base-free synthesis of phosphonates and phosphates on Al2O3
-
Al2O3-supported solvent free condensation of alkylphosphonic dichlorides with alcohols at room temperature yielded phosphorus esters in excellent yields.
- Acharya, Jyotiranjan,Shakya, Purushottam D.,Pardasani, Deepak,Palit, Meehir,Dubey, Devendra K.,Gupta, Arvind K.
-
p. 194 - 196
(2007/10/03)
-