Addition Of Dialkyl Phosphites Research Articles

Magnesium Perchlorate Catalyzed Phospha-Michael Addition of Dialkyl Phosphite to Chalcone

Aim and Objective: Phosphonate possesses a broad range of applications ranging from agrochemistry to medicines. Because of the synthetic and biological importance of phosphonate, their chemistry has stimulated an increasing interest. Hence we developed an efficient and eco-friendly Mg(ClO4)2 catalyzed one pot, solvent free synthesis of phosphonate derivatives of chalcones. Materials and Methods: Magnesium perchlorate phosphonate derivatives of chalcones were synthesized. The reactions were executed at room temperature in the presence of Anhydrous Magnesium perchlorate Anhy. Mg(ClO4)2 under solvent free condition, affording high yield of the product. The cardinal significance of the method lies in its uncomplicated and eco- friendly experimental conditions. Results: The PMA method for P-C bond formation, using dialkyl phosphite with chalcone, was performed in the presence of Anhydrous Magnesium perchlorate under solvent free condition. Despite the solvent free condition, the methodology is efficient since it is required only in catalytic amount of Anhy. Mg(ClO4)2 in one pot reaction. Results demonstrated that the catalytic PMA of dimethyl phosphite, diethyl phosphite, diisopropyl phosphite and dibutyl phosphite with chalcone generates desired products with a percentage yield of 60-80%. Conclusion: We have developed a new efficient PMA method for P-C bond formation, using dialkyl phosphite with α,β-unsaturated ketone i.e. chalcone. To the best of our knowledge, Anhy. Mg(ClO4)2 catalyzed phosphamicheal addition of dialkyl phosphite with chalcones was found to be a new and efficient method for various biological applications.

Radical‐Initiated Reaction of Methyl Linoleate with Dialkyl Phosphites

AbstractThe addition of dialkyl phosphite (methyl, ethyl and n‐butyl) to methyl linoleate (MeLin) double bonds was investigated. The reaction proved to be more challenging than the analogous reaction with methyl oleate (MeOl), due to inhibition of the radical reaction by the bis‐allylic hydrogens of MeLin and the lower reactivity of MeLin double bonds. However, we demonstrated that this self‐inhibition problem can be solved by simply keeping the MeLin reagent at low concentrations, while keeping the dialkyl phosphite at high concentrations. For optimization of the reaction, four different radical initiators were investigated: dilauroyl peroxide (LP), 2,2′‐azobis(2‐methylpropionitrile) (AIBN), tert‐butyl perbenzoate (t‐BP), and tert‐butyl peroxide (TOOT). The initiators were used at temperatures that provided a half‐life of 10 h: 64, 64, 104, and 125 °C respectively for LP, AIBN, t‐BP, and TOOT. The tests showed the reaction to be faster at higher temperatures, but transesterification of the ester groups was also observed at elevated temperatures. t‐BP was chosen as an optimal initiator for carrying the reaction. The apparent order of reactivity of the dimethyl, diethyl and di‐n‐butyl phosphites (Me >Et >n‐Bu) towards MeLin was due to differences in their molar volumes. When the concentrations of dialkyl phosphite were kept the same, the order reversed (n‐Bu > Et~Me). GC–MS spectra of the resulting phosphonates are reported and the main fragments assigned.

The Addition of Dialkyl Phosphites and Diphenylphosphine Oxide on the Triple Bond of Dimethyl Acetylenedicarboxylate under Solvent-Free and Microwave Conditions

The addition of dialkyl phosphites or diphenylphosphine oxide to the triple bond of dialkyl acetylenedicarboxylate may result in mono- and/or bisadducts. The ratio of the products may be influenced by the molar ratio of the reactants and the conditions (temperature of microwave irradiation and reaction time). Stereospecific (3)J(PP) couplings were utilized in the assignments to the meso and racemic forms of the bisadducts. The bis(dialkylphosphonyl)-succinates were formed as a mixture of the corresponding meso form and racemate, while bis(diphenylphosphinoyl)-succinate was obtained as a racemate. The P-31-(CH)-C-12-(CH)-C-13-P-31 spin system of bis(dialkylphosphonyl)-succinates was subjected to a detailed NMR analysis supported by simulation.

Environmentally Friendly Syntheses and Tools

Recent results obtained by our group on MW-assisted reactions, such as the alkylation of P˭O-functionalized CH-acidic compounds and the addition of dialkyl phosphites to α-ketophosphonates, are summarized together with the rational synthesis of hydroxy-methylene bis(phosphinic acids).

3‐P⩵O‐Functionalized Phospholane 1‐Oxides by the Michael Reaction of 1‐Phenyl‐2‐phospholene 1‐Oxide and Dialkyl Phosphites, H‐Phosphinates, or Diphenylphosphine Oxide

ABSTRACTThe addition of dialkyl phosphites, H‐phosphinates, and diphenylphosphine oxide on the β carbon atom of the not too reactive double bond of 1‐phenyl‐2‐phospholene 1‐oxide was carried out in two ways. According to the first approach (A), the P‐reagents were activated by trimethylaluminum prior to the Michael addition. The second method (B) involved the microwave(MW)‐assisted solventless reaction of the P‐species with the phospholene oxide. In general, method A was more efficient and more selective than route B. However, the addition of dialkyl phosphites and diphenylphosphine oxide could also be accomplished well under MW conditions. The disadvantage of the MW‐assisted approach is that the Michael adducts are formed as a mixture of isomers. The 3‐P⩵O‐phospholane oxides are novel products, and among these, the bis(phosphine oxide) is the precursor of the bidentate P‐ligand LuPhos.

ChemInform Abstract: Microwave‐Assisted Phospha‐Michael Addition of Dialkyl Phosphites, a Phenyl‐H‐phosphinate, and Diphenylphosphine Oxide to Maleic Derivatives.

AbstractA variety of new P‐substituted succinic acid derivatives is synthesized via microwave‐assisted phospha‐Michael addition of phosphites, phosphinates or phosphine oxides to maleimide or maleic acid derivatives.

Microwave‐assisted phospha‐michael addition of dialkyl phosphites, a phenyl‐H‐phosphinate, and diphenylphosphine oxide to maleic derivatives

AbstractA series of new >P(O)‐substituted succinic derivatives was synthesized by the microwave‐assisted phospha‐Michael addition of dialkyl phosphites, ethyl phenyl‐H‐phosphinate, and diphenylphosphine oxide to N‐phenyl and N‐methyl maleimide, as well as to maleic acid anhydride. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:235–240, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21007

Microwave‐assisted synthesis of α‐hydroxy‐benzylphosphonates and ‐benzylphosphine oxides

AbstractA series of α‐hydroxy‐benzylphosph‐ onates and ‐benzylphosphine oxides was synthesized by the Na2CO3‐catalyzed microwave‐assisted addition of dialkyl phosphites and dipenylphosphine oxide to P‐substituted benzaldehydes. The solventless reaction provided the products in short reaction times and in 71–88% yield. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 22:15–17, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20649

Addition of Phosphites to N,N-Diferrocenylidene-1,3-phenylenedimethylamine and N,N-Diferrocenylidene-1,3-cyclohexylenedimethylamine: Synthesis of Corresponding Model Bis-Aminophosphonates

The preparation of tetraalkyl 1,3-phenylene-di(methylamino)-di-ferrocenylmethyl-phosph onates (4a–c) and tetraalkyl 1,3-cyclohexylene-di(methylamino)-di-ferrocenylmethylphosph onates (5a–c) by the addition of dialkyl phosphites to N,N-diferrocenylidene-1,3-phenylenedimethylamine 1 and N,N-diferrocenylidene-1,3-cyclohexylenedimethylamine 2 is described. The diastereoselectivity, which was observed in both cases, is consistent with that observed in other cases.

Lewis Acid–Mediated Nucleophilic Addition of Dialkylphosphite to C=N Double Bond of Hydrazones

The synthesis of new phenyl substituted derivatives ( 2) of α -hydrazino-alkylphosphonic acids by Lewis acid–mediated addition of dialkylphosphite to hydrazones, derived from benzoylhydrazines and benzaldehydes, is described. Reactions were successfully promoted by boron trifluoride etherate under mild conditions in methylene chloride at room temperature.

Radical addition of dialkyl phosphites: Application in organic synthesis

Synthesis and application of phosphorylated esters, alcohols, ketones, epoxides, carbamates and carbamides, amino acids, and pyrimidines is reviewed.

Synthesis and NMR Spectroscopic Study of New Furan-Derived Bis(Aminophosphonates)

The synthesis of two novel furyl-containing bis(aminophosphonates) 1,5-bis[N-methyl(dimethoxyphosphonyl)-1-(2-furyl)]diaminonaphthalene (1) and 1,5-bis[N-methyl(diethoxyphosphonyl)-1-(2-furyl)]diaminonaphthalene (2) through an addition of dialkyl phosphites to N,N′-difurfurylidene-1,5-naphthalenediamine is reported. The compounds have been characterized by elemental analysis, TLC, IR and NMR (1H, 1C and 31P) spectra. Some new 31P NMR data of three previously described analogues (3–5) of the above bis(aminophosphonates) is also presented. The 31P NMR study reveals that in most of the cases (1, 3–5), the addition reaction is completely stereoselective, and only one diastereomer is formed. By the preparation of compound 2, this reaction proceeds not completely stereoselectively with the predominant formation (in 90%) of one of the two possible diastereomers.

Enantiomerically Pure 4‐Amino‐1,2,3‐trihydroxybutylphosphonic Acids.

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Enantiomerically pure 4-amino-1,2,3-trihydroxybutylphosphonic acids

(1 S,2 R,3 S)-, (1 R,2 R,3 S)- and (1 S,2 R,3 R)-4-amino-1,2,3-trihydroxybutylphosphonic acids were synthesised. The synthetic strategy involved preparation of the respective 4-azido-2,3- O-isopropylidene- l-threose or - d-erythrose, addition of dialkyl phosphites, separation of C-1 epimeric O, O-dibenzyl phosphonates, the reduction of azides and the removal of the protecting groups. The (2 R,3 S) and (2 R,3 R) configurations in the final products were secured by employing diethyl l-tartrate and d-isoascorbic acid as starting materials. The stereochemical course of the addition to the carbonyl groups in 4-azido-2,3- O-isopropylidene- l-threose or - d-erythrose followed that established earlier for 2,3- O-isopropylidene- d-glyceraldehyde and similar (3:1–4:1) diastereoselectivities were achieved.

NOUVELLES VOIES D'ACCES AUX 2-ETHOXYCARBONYLALLYLPHOSPHONATES

The Michaelis-Arbusov reaction (method A) and the nucleophilic addition of dialkylphosphites followed by Hoffman olefination (method B) represent two synthetic methods giving a variety of 2-ethoxycarbonylallyl-phosphonates 2, in good yields, from readily accessible ethyl 2-(N,N-dialkylaminomethyl) acrylates 1.

Behavior of 3,6-bis(vinylsulfonyl)-1,2,4,5-tetrafluorobenzene in homolytic addition of dialkyl phosphites

Reaction of 3,6-bis(vinylsulfonyl)-1,2,4,5-tetrafluorobenzene with dialkyl phosphites at thermal initiation (70°C) gives rise to 3,6-bis(dialkoxyphosphonoethylsulfonyl)-1,2,4,5-tetrafluorobenzenes in up to 45% yield. The formation of diethoxyphosphonyl radicals in the course of the reaction was observed with the use of ESR method applying spin trapping by 2-methyl-2-nitrosopropane. The use as initiator of the azo-bis-isobutyronitrile increased the yield of diadducts to 60%.

Asymmetric Synthesis of Aminophosphonic Acids and Trifluoromethylated Derivatives Thereof

Various approaches leading to chiral aminophosphonic acids were described. Catalytic asymmetric-induced addition of dialkylphosphite to chiral aldimine gives low ee. value. The diastereoselective alkylation of bicyclic phosphonamide derived from anilinomethylpyrrolidine and followed by subsequent reactions provide much better results. 1,3-Proton Schiff reaction was applied successfully for chiral trifluoromethylated f - and/or g -aminophosphonic acids.

Kinetics and Mechanism of the Pudovik Reaction in the Series of Shiff Bases. Addition of Dialkylphosphites to Substituted N-Alkyl(Aryl)Benzylideneamines

Kinetic and preparative investigation of the reaction of addition of dialkylphosphites to a serias of Shiff bases of the type Ar-CH˭N-R (R = Alk, Ar3) (1) is investigated. On the basis of kinetic data obtained (Table) the nucleophilic addition mechanism is suggested.

ADDITION PRODUCTS OF DIALKYL PHOSPHITES TO A DIFURYL-CONTAINING SCHIFF BASE

Abstract New difuryl-containing diesters of aminophosphonic acids were synthesized through addition of dialkyl phosphites (dimethyl- and diisopropyl phosphite) to bis[4-(furfurylidene amino)-phenyl]methane. The reaction was carried out in the presence of an alkaline catalyst at ambient temperature. The structure of the compounds prepared was confirmed by means of IR, 1H- and 31P-NMR spectroscopy. TLC data are also presented.

THE SYNTHESIS AND FAB MASS ANALYSIS OF O,O-DIALKYL 1-BENZYLAMINOBENZYLPHOSPHONATES, PRECURSORS OF IMPORTANT STRUCTURAL UNITS IN ANTI-THROMBOTIC TRIPEPTIDES

Abstract O,O-Dialkyl 1-benzylaminobenzylphosphonates (3) formed in quantitative yield at R.T. by the nucleophilic addition of dialkyl phosphite (1) to benzylidenebenzylamines (2) in CH2C12 give highly characteristic fragmentation patterns in their positive ion FAB mass spectrum. Catalytic hydrogenolysis of these precursors produces ‘P1’ structural units which when incorporated into substrate-like peptides, form potent inhibitors of thrombin.