Hydroxy Phosphonates Research Articles

Lewis Acid Enables Ketone Phosphorylation: Synthesis of Alkenyl Phosphonates

Main observation and conclusionAn efficient Lewis acid enabled ketones phosphonylation to synthesize vinylphosphonates has been developed. This method relays on ketone hydrophosphonylation/α‐hydroxy phosphonates unimolecular elimination (E1) dehydration cascade reaction sequence. Various C—P bond formation products were obtained in moderate to excellent yields with water as the only byproduct in the reaction.

ChemInform Abstract: A Simple Heterogeneous Catalyst for Phosphite Addition on Carbonyl Groups.

Abstractα‐Hydroxy phosphonates are efficiently obtained by selective addition of phosphites to the carbonyl group of aldehydes and ketones using hydrotalcite MG70 as reusable and cheap heterogeneous catalyst under solvent‐free conditions.

Synthesis of Quaternary α‐Hydroxy Phosphonates via Direct Hydroxylation of Phosphonate Compounds

AbstractIt was found for the first time that Cs2CO3 serves as highly efficient catalyst for the direct hydroxylation reactions of phosphonates under mild conditions. This reaction provides an efficient approach to quaternary α‐hydroxy phosphonates, which possess intriguing biological activities and are widely used in many areas.

Enantioselective Copper-Catalyzed O-H Insertion of α-Diazo Phosphonates

A copper-catalyzed asymmetric O-H insertion of α-di-azophosphonates with alcohols by using chiral spiro bisoxazoline ligandswas developed. The insertion reaction exhibited good yields (upto 89%) with high enantioselectivities (up to 98% ee)and provided an efficient approach for synthesis of enantiomericallyenriched α-alkoxy and hydroxy phosphonate derivatives startingfrom readily available materials.

Synthesis and Herbicidal Activity of α‐Hydroxy Phosphonate Derivatives Containing Pyrimidine Moiety

AbstractA series of α‐hydroxy phosphonate derivatives containing pyrimidine moiety were designed and synthesized. Their structures were characterized by IR, 1H NMR, MS and elemental analysis. The results of preliminary herbicidal activities (in vitro) showed that some of the title compounds 2 exhibited moderate herbicidal activities against dicotyledonous weeds (Brassica campestris L), and most of compounds 2 showed better activity against dicotyledonous weeds than monocotyledonous weeds (Echinochloa crus‐galli). Further bioassays (in vivo) indicated that some of the title compounds 2 possessed good and selective herbicidal activity against amaranth pigweed (A. retroflexus) in both pre‐ and post‐emergence treatments at the dose of 1.5 kg/ha. For exmple, compounds 2a, 2b and 2e exhibited 100% inhibition against A. retroflexus in pre‐emergence treatment, and 91.7%, 98.8% and 99.5% inhibition in post‐emergence treatment at the dose of 1.5 kg/ha, respectively.

ChemInform Abstract: Synthesis of Enantiomerically Pure 2′,3′,5′-Trideoxy-4′-[(diethoxyphosphoryl)difluoromethyl]thymidine Analogues.

D- and L-(diethoxyphosphoryl)difluoromethyl nucleoside analogues 10 have been synthesized using the building block approach, starting from chiral fluorinated molecules. The key steps of the synthetic sequence were condensation of 2-methyl-5-(4-methylphenylsulfinyl)pent-2-ene (1) and ethyl 2-(diethoxyphosphoryl)-2,2-difluoroacetate (2), reduction of the thus formed ketones 3 to alcohols 4, reductive removal of the sulfur moiety to give hydroxy phosphonates 6, and oxidative cyclization to give furanose derivatives 8.

술팜산: 초음파 조사를 이용한 α-히드록시 인산염 합성의 효과적인 촉매

무용제하에서 <TEX>$\alpha$</TEX>-히드록시 인산염을 합성하기 위해 술팜산은 비용효율이 높고 일반적인 산들의 친환경적인 대안으로 활용되었다. 초음파 조사를 이용하여 더 나은 수율을 얻었고 반응시간이 짧았다. Sulphamic acid has been exploited as a cost-effective catalyst and green alternative for conventional acidic materials to synthesize <TEX>$\alpha$</TEX>-hydroxy phosphonates under solvent-free condition. The reaction carried out using ultrasound irradiation with better yields and shorter reaction time.

Asymmetric Hydrogenation of Enamides, α-Enol and α-Enamido Ester Phosphonates Catalyzed by IndolPhos-Rh Complexes

The scope of the IndolPhos-Rh-catalyzed asymmetric hydrogenation of enamides, alpha-enol and alpha-enamido ester phosphonates, has been investigated. In addition, Taddol-based IndolPhos ligands are introduced. High activities and good to excellent enantioselectivities up to 99% ee are obtained for a broad range of structurally diverse substrates, giving important chiral products such as alpha, beta(2), and beta(3) amino acid derivatives, arylamines, and amino and hydroxy phosphonates.

4-Aminophenyl Diphenylphosphinite (APDPP) as a Heterogeneous and Acid Scavenger Reagent for Thiocyantion or Isothiocyanation of Alcohols and Protected Alcohols

4-Aminophenyl diphenylphosphinite (APDPP) as a heterogeneous phosphinite reagent is used for the efficient conversion of alcohols, trimethylsilyl- and tetrahydropyranyl ethers, α -hydroxy phosphonates, and α -trimethylsilyloxyphosphonates to their corresponding thiocyanates or isothiocyanates in the presence of Br 2 and NH 4 SCN.

ChemInform Abstract: Synthesis of Cyclopentenones via Intramolecular HWE and the Palladium‐Catalyzed Reactions of Allylic Hydroxy Phosphonate Derivatives.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis of Cyclopentenones via Intramolecular HWE and the Palladium-Catalyzed Reactions of Allylic Hydroxy Phosphonate Derivatives

Palladium-catalyzed decarboxylative rearrangement of nonracemic phosphono allylic acetoacetates, or the intermolecular allylic substitution of nonracemic phosphono allylic carbonates with tert-butyl acetoacetate followed by hydrolysis and decarboxylation, gave omega-ketovinyl phosphonates. A highly regioselective Wacker oxidation gave the omega,beta-diketophosphonates which underwent intramolecular HWE reaction to give nonracemic cyclopentenones. An aldol condensation leading to phosphonocyclopentenones was competitive with the HWE reaction. The stereochemistry of the cyclopentenone and the ratio of HWE to aldol products were dependent upon the choice of base used in the reaction.

Chiral Hydroxy Phosphonates: Synthesis, Configuration and Biological Properties

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

A method for determining the optical purity of hydroxy phosphonates using cinchonidine as chiral solvating reagent

A method for determining the optical purity of hydroxy phosphonates using cinchonidine as chiral solvating reagent

Allylic Hydroxy Phosphonates: Versatile Chiral Building Blocks.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthesis of Nonracemic Allylic Hydroxy Phosphonates via Alkene Cross Metathesis.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Allylic hydroxy phosphonates: versatile chiral building blocks

Allylic hydroxy phosphonates are converted into β and γ substituted amino phosphonates using a series of palladium-catalyzed reactions. The judicious selection of nitrogen nucleophile and palladium catalyst allow for excellent regio- and stereochemical control. Palladium(0)-catalyzed amine addition or tosyl carbamate rearrangement gives rise to the γ-substituted phosphonates, whereas, reaction of tosyl carbamates with palladium (II) and base gives oxazolidinones (β-substitution).

Synthesis of Nonracemic Allylic Hydroxy Phosphonates via Alkene Cross Metathesis

Allylic hydroxy phosphonates and their derivatives can be interconverted by using cross metathesis with second generation Grubbs catalyst. The absolute stereochemistry of the starting phosphonate is conserved in the product. Cross metathesis reaction of the acrolein-derived phosphonate 2a yields a series of functionalized allylic hydroxy phosphonates. However, the cross metathesis reaction is often accompanied by competing dimerization and alkene migration reactions leading to a reduction in yield. The cinnamaldehyde- and crotonaldehyde-derived phosphonates 2b and 2c were also examined. In general, the metathesis reactions of phosphonates 2b and 2c are considerably slower than those for phosphonate 2a leading to mixtures. Several hydroxyl-protected derivatives of the phosphonate 2a (methyl carbonate 3a, acetate 4a, N-tosyl carbamate 5a, TBDMS 6a, and acetoacetate 7a) undergo metathesis without competing side reactions to give substituted allylic phosphonates in good to excellent yield.

Stereospecific Pd(O)‐Catalyzed Malonate Additions to Allylic Hydroxy Phosphonate Derivatives: A Formal Synthesis of (‐)‐Enterolactone.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Stereospecific Pd(O)-catalyzed malonate additions to allylic hydroxy phosphonate derivatives: a formal synthesis of (-)-enterolactone.

A combination of cross-metathesis and malonate addition was applied to a formal synthesis of the mammalian lignan enterolactone 5. The cross-metathesis of alkene 6 and phosphonate 3a gave the substituted allylic phosphonate 3d. The palladium-catalyzed addition of malonate 10d to the allylic phosphonate 3d was stereospecific and highly regioselective and yielded the vinyl phosphonate 11d. The vinyl phosphonate 11d was converted in two steps into the lactone 14, a known intermediate in the synthesis of enterolactone 5.

Stereospecific Pd(0)‐Catalyzed Arylation of an Allylic Hydroxy Phosphonate Derivative: Formal Synthesis of (S)‐(+)‐ar‐Turmerone.

AbstractFor Abstract see ChemInform Abstract in Full Text.