- Desymmetrization of Phosphinic Acids via Pd-Catalyzed Asymmetric Allylic Alkylation: Rapid Access to P-Chiral Phosphinates
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The synthesis of P-chiral compounds is challenging, especially since useful catalytic methods for preparing such molecules are scarce. Herein we disclose a desymmetrization that employs phosphinic acids as prochiral nucleophiles in a Pd-catalyzed asymmetr
- Trost, Barry M.,Spohr, Simon M.,Rolka, Alessa B.,Kalnmals, Christopher A.
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p. 14098 - 14103
(2019/10/11)
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- New aspects connected with the synthesis of H-phosphinate anhydrides
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A novel reaction between sodium salt of phenylphosphinic acid PhP(O)(OH)H (1) and various phosphorus electrophiles, R2P(O)C1 (2; R = alkyl, aryl, alkoxy or aryloxy) has been described. The presented reaction showed a high selectivity (yield up to 96%) in the products of the symmetric phosphorus anhydrides, R2P(O)-O-(O)PR2(4), which preferentially come from the starting phosphorus electrophiles (2). The results demonstrate that the phosphorus-phosphorus mixed anhydrides, RPH(O)-O-(O)PR2(3) are unstable under basic condition and possibly decomposed with expulsion of a phosphinylidene (Ph-P=O) fragment (6).
- Nycz
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experimental part
p. 589 - 594
(2009/12/26)
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- Aminophosphine oxides in a pyridine series. Studies on the cleavage of pyridine-2- and pyridine-4-yl-(N-benzylamino)-methyldiphenylphosphine oxides in acidic solutions
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The synthesis and reactions of 1-(N-benzylamino)-1-(2-pyridyl)- and 1-(N-benzylamino)-1-(4-pyridyl)-methyldiphenylphosphine oxides are described. It was found that these compounds were exceptionally easy to cleave in aqueous sulfuric acid solutions to form diphenylphosphinic acid and the corresponding N-(pyridylmethyl)-benzylamines. The structure of a single diastereoisomer, that is, the (R)-(+)-1-[N-(α-methylbenzylamino)]-1-(4-pyridyl)-(S)-methyldiphen ylphosphine oxide was determined by X-ray crystallography. The acidic alcoholysis of the selected model chiral pyridine aminophosphine oxides was investigated by means of 31P NMR spectroscopy. The cleavage kinetics were also studied. On the basis of the obtained results, a mechanism of the cleavage was formulated.
- Goldeman, Waldemar,Olszewski, Tomasz K.,Boduszek, Bogdan,Sawka-Dobrowolska, Wanda
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p. 4506 - 4518
(2007/10/03)
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- New approaches to the synthesis of diphosphine dioxides and hypophosphoric acid esters
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An union >P-O- has been applied as an efficient synthetic precursor of four coordination compounds of the R2P(O)-(O)PR 2 type, namely diphosphine dioxides (R = alkyl, aryl) as well as hypophosphoric acid esters (R = alkoxy, aryloxy), in a one-pot reaction. Furthermore, there were elaborated some mechanistic aspects of the origin of the >P(O)-O-(O)PP-O- and >P(O)X (X= Cl, Br) electrophiles. Attention is focused on the synthesis of the >P(O)-(O)P compounds.
- Nycz, Jacek E.,Musiol, Robert
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p. 310 - 316
(2007/10/03)
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- Reactivity of diacyloxyiodobenzenes toward trivalent phosphorus nucleophiles
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The reaction of diacyloxyiodobenzenes and tetravalent phosphorus nucleophiles was investigated. It was established that both H-phosphonates and secondary phosphine oxides react with diacetoxyiodobenzene in alcohols in the presence of sodium alcoholates yi
- Makowiec, Slawomir,Rachon, Janusz
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p. 352 - 359
(2007/10/03)
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- The reactions of dialkyl phosphites and phosphine oxides with iodosylbenzene
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The reaction of iodosylbenzene with > P(O)H type of acids (dialkyl phosphites, secondary phosphine oxides) was studied. The acids of >P(O)H type add to iodosylbenzene to yield intermediate 6 which in the aprotic solvents yields oxidation products, it means >P(O)OH acids and/or anhydride of >P(O)OP(O) P(O)OR ester is the major product.
- Makowiec, Slawomir,Rachon, Janusz
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p. 941 - 955
(2007/10/03)
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- Reductive cleavage of the halogen-phosphorus, oxygen-phosphorus and phosphorus-phosphorus bonds with alkali metals
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The reduction of phosphorus acid chlorides as well as hypophosphates, pyrophosphates and mixed P(III)-P(V) anhydrides with alkali metals (Li, Na, K) in NH3 liq. / THF solution and potassium naphthalenide was investigated. It was found that this type of phosphorus compounds easily undergo reduction: a) >P(O)Cl to >P(O)H; b) >P(O)P(O)P(O)H; c) >P(O)-O-P(O)P(O)OH and >P(O)H; d) >P(O)-O-PP(O)O- and >P-. The results of our experiments strongly suggest that the mixed P(III)-P(V) anhydride is reduced by potassium naphthalenide in THF with the cleavage of the P(III)-oxygen bond.
- Nycz, Jacek,Rachon, Janusz
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- Phosphoric-Carboxylic Anhydrides. New Synthetic Procedures and Reactions with Nucleophiles. Reexamination of the Reaction of Se-alkyl-phosphoroselenoates with Alcohols and Mercuric Trifluoroacetate
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Phosphorus trimethylsilyl esters RR'P(O)OSiMe3 react smoothly with carboxylic anhydrides to give phosphoric-carboxylic anhydrides RR'P(O)-O-COR" in excellent yield.A similar reaction proceeds between stannyl esters RR'P(O)OSnMe3 and carboxylic anhydrides.We also have found that the anhydrides RR'P(O)-O-COCF3 are formed in almost quantitative yield when the phosphorus acid halides RR'P(O)X (X=Cl,Br,I) are allowed to react with trifluoroacetic anhydride in the presence of N-methylimidazole. We were able to confirm again that acyclic phosphoric-carboxylic anhydrides exhibit acetylating properties towards amines and alcohols.Our findings contradict with those of Wozniak, Krzyzanowska and Stec relating to the reaction of Se-alkylphosphoroselenoates RR'P(O)SeR" with mercuric trifluoroacetate Hg(OCOCF3)2.Our interpretation of this reaction differs entirely from those presented by the above mentioned authors. Key words: phosphorus-carboxylic anhydrides, Se-alkyl-phosphoroselenoates
- Wasiak, J.,Helinski, J.,Dabkowski, W.,Skrzypczynski, Z.,Michalski, J.
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p. 1027 - 1032
(2007/10/02)
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- OPTICALLY ACTIVE TRIORGANOSILYL ESTERS OF PHOSPHORUS. SYNTHESIS AND STRUCTURE
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We report this synthesis of the first optically active silyl esters of phosphorus having two centres of chirality : one on silicon and the other on phosphorus.Compounds are obtained of general formula : t-BuPhP(X)YSiαNpPhMe X,Y=O, O(1); S, O(2); Se, O(3); S, S(4); doublet, O(5) including 1 and 3 with optical activity located on Si, 2 and 5 with the activity on Si or P and on both these centres, 4 only racemic.Absolute configurations are determined. 31P and 29Si NMR spectra of these models and their trimethylsilyl analogues are reported.The triorganosilyl group is always preferentially bound to phosphorus through oxygen atom.Surprisingly, diastereotopic NMR chemical shifts exclude the fast 1,3 migration in esters 1 and 4. 29Si NMR spectra correspond to a tetracoordinate silicon atom.
- Chojnowski, J.,Cypryk, M.,Michalski, J.,Wozniak, L.,Corriu, R.,Lanneau, G.
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p. 385 - 398
(2007/10/02)
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- Synthesis of S-Sulfonyl-Phosphinothioates and Phosphinodithioates, a Novel Organophosphorus-sulphur Structure
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Racemic and optically active S-sulphonylphosphinothioates R-SO2-S-P(O)ButPh and dithioates R-SO2-S-P(S)ButPh (R = Me, p-tolyl) have been prepared for the first time by the reaction of the corresponding acids ButPhP(S)SH(X = O,S) of their salts with sulphonylating reagents RSO2-Y (Y = Cl, O-SO2R, triazolide).
- Dabkowski, Wojciech,Lopusinski, Andrzej,Michalski, Jan,Radziejewski, Czeslaw
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p. 375 - 378
(2007/10/02)
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