In organic chemistry, phosphonates or phosphonic acids are organophosphorus compounds containing groups (where R = alkyl, aryl, or just hydrogen). Phosphonic acids, typically handled as salts, are generally nonvolatile solids that are poorly soluble in organic solvents, but soluble in water and common alcohols.
Many commercially important compounds are phosphonates, including glyphosate (the active molecule of the herbicide Roundup), and ethephon, a widely used plant growth regulator. Bisphosphonates are popular drugs for treatment of osteoporosis.
In biochemistry and medicinal chemistry, phosphonate groups are used as stable bioisosteres for phosphate, such as in the antiviral nucleotide analog, Tenofovir, one of the cornerstones of anti-HIV therapy. And there is an indication that phosphonate derivatives are "promising ligands for nuclear medicine."
Phosphonates feature tetrahedral phosphorus centers. They are structurally closely related to (and often prepared from) phosphorous acid.
Phosphonate salts are the result of deprotonation of phosphonic acids, which are diprotic acids:
RPO(OH)2 + NaOH → H2O + RPO(OH)(ONa) (monosodium phosphonate)
RPO(OH)(ONa) + NaOH → H2O + RPO(ONa)2 (disodium phosphonate)
Phosphonate esters are the result of condensation of phosphonic acids with alcohols.
Several methods exist for the preparation of phosphonic acids and their salts.
Most processes begin with phosphorous acid (aka phosphonic acid, H3PO3), exploiting its reactive P−H bond.
Phosphonic acid can be alkylated via the Kabachnik–Fields reaction or Pudovik reaction to give aminophosphonate, which are useful as chelating agents. One example is the industrial preparation of nitrilotris(methylenephosphonic acid):
NH3 + 3 H3PO3 + 3 CH2O → N(CH2PO3H2)3 + 3 H2O
Phosphonic acid also can be alkylated with acrylic acid derivatives to afford carboxyl functionalized phosphonic acids. This reaction is a variant of the Michael addition:
CH2=CHCO2R + 3 H3PO3 → (HO)2P(O)CH2CH2CO2R
In the Hirao coupling dialkyl phosphites (which can also be viewed as di-esters of phosphonic acid: (O=PH(OR)2) undergo a palladium-catalyzed coupling reaction with an aryl halide to form a phosphonate.
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
Organophosphorus chemistry is the scientific study of the synthesis and properties of organophosphorus compounds, which are organic compounds containing phosphorus. They are used primarily in pest control as an alternative to chlorinated hydrocarbons that persist in the environment. Some organophosphorus compounds are highly effective insecticides, although some are extremely toxic to humans, including sarin and VX nerve agents. Phosphorus, like nitrogen, is in group 15 of the periodic table, and thus phosphorus compounds and nitrogen compounds have many similar properties.
In organic chemistry, a phosphite ester or organophosphite usually refers to an organophosphorous compound with the formula P(OR)3. They can be considered as esters of an unobserved tautomer phosphorous acid, H3PO3, with the simplest example being trimethylphosphite, P(OCH3)3. Some phosphites can be considered esters of the dominant tautomer of phosphorous acid (HP(O)(OH)2). The simplest representative is dimethylphosphite with the formula HP(O)(OCH3)2. Both classes of phosphites are usually colorless liquids.
In organic chemistry, phosphinites are organophosphorus compounds with the formula . They are used as ligands in homogeneous catalysis and coordination chemistry. Phosphinites are prepared by alcoholysis of organophosphinous chlorides. For example, treatment of chlorodiphenylphosphine with methanol and base gives methyl diphenylphosphinite: ClPPh2 + CH3OH → CH3OPPh2 + HCl Although they are esters of phosphinous acids (R2POH), phosphinites are not made via such intermediates.
Explores degradation pathways in photoelectrochemical systems, focusing on artificial photosynthesis and electrode modifications.
Explores redox reactions of aldehydes, including Evans-Tishchenko, Cannizzaro, and Benzoin reactions, reduction of imines, and Wittig reaction variants.
Delves into the environmental impact of phthalates, covering their presence in everyday objects, regulations, and mitigation strategies.
The removal of organophosphorus (OP) herbicides fromwater hasbeen studied using adsorptive removal, chemical oxidation, electrooxidation,enzymatic degradation, and photodegradation. The OP herbicide glyphosate(GP) is one of the most used herbicides worldwi ...
AMER CHEMICAL SOC2023
, , ,
Competitive adsorption of dilute quantities of certain organic molecules and water at silicate surfaces strongly influence the rates of silicate dissolution, hydration, and crystallization. Here, we determine the molecular-level structures, compositions, a ...
American Chemical Society2015
The photo-Fenton process is a promising emerging technology for the treatment of contaminated water streams. It is based on the generation of reactive oxygen species that are capable of destroying recalcitrant contaminants otherwise unaffected by conventio ...