- Diphenyl Diselenide-Catalyzed Synthesis of Triaryl Phosphites and Triaryl Phosphates from White Phosphorus
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Industrially important triaryl phosphites, traditionally prepared from PCl3, have been synthesized by a diphenyl diselenide-catalyzed one-step procedure involving white phosphorus and phenols, which provides a halogen- and transition metal-free way to these compounds. Subsequent oxidation of triaryl phosphites produces triaryl phosphates and triaryl thiophosphates. Phosphorotrithioates are also prepared efficiently from aromatic thiols and aliphatic thiols.
- Zhang, Yue,Cai, Ziman,Chi, Yangyang,Zeng, Xiangzhe,Chen, Shuanghui,Liu, Yan,Tang, Guo,Zhao, Yufen
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supporting information
p. 5158 - 5163
(2021/07/20)
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- Ni-Catalyzed Regioselective β,δ-Diarylation of Unactivated Olefins in Ketimines via Ligand-Enabled Contraction of Transient Nickellacycles: Rapid Access to Remotely Diarylated Ketones
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We disclose a [(PhO)3P]/NiBr2-catalyzed regioselective β, δ-diarylation of unactivated olefins in ketimines with aryl halides and arylzinc reagents. This diarylation proceeds at remote locations to the carbonyl group to afford, after simple H+ workup, diversely substituted β, δ-diarylketones that are otherwise difficult to access readily with existing methods. Deuterium-labeling and crossover experiments indicate that diarylation proceeds by ligand-enabled contraction of transient nickellacycles.
- Basnet, Prakash,Dhungana, Roshan K.,Thapa, Surendra,Shrestha, Bijay,Kc, Shekhar,Sears, Jeremiah M.,Giri, Ramesh
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supporting information
p. 7782 - 7786
(2018/06/22)
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- Simple phosphonic inhibitors of human neutrophil elastase
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Herein, we describe the synthesis and resulting activity of a complex series of α-aminophosphonate diaryl esters as irreversible human neutrophil elastase inhibitors and their selectivity preference for human neutrophil elastase over several other serine proteases such as porcine pancreatic elastase, trypsin, and chymotrypsin. We synthesized and examined the inhibitory potency of several new simple Cbz-protected α- aminoalkylphosphonate diaryl esters that yielded several new HNE inhibitors, where one of the obtained compounds Cbz-ValP(OC6H 4-4-COOMe)2 displayed an apparent second-order inhibition value at 33,015 M-1 s-1.
- Sieńczyk, Marcin,Winiarski, ?ukasz,Kasperkiewicz, Paulina,Psurski, Mateusz,Wietrzyk, Joanna,Oleksyszyn, Józef
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supporting information; experimental part
p. 1310 - 1314
(2011/04/16)
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- Wittig-Horner approach for the synthesis of tamoxifen
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A stereoselective synthesis of Z-tamoxifen, a tetra-substituted alkene with antiestrogenic activity, is described. The Wittig-Horner reaction has been employed as the key step to establish the olefin stereochemistry. Copyright Taylor & Francis, Inc.
- Pandey, Rajesh K.,Wakharkar,Kumar, Pradeep
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p. 2795 - 2800
(2007/10/03)
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- Selective synthesis of organophosphites
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Disclosed herein is a process for the selective synthesis of triorganophosphites intermediates, including chloridites and dichloridites, from PX3 (X=Cl, Br or I), alcoholos and triorganoamines where alcohol and triorganoamine are added either (a) separately and concurrently, or (b) alternating equimolar portions of amine and alcohol.
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- Nickel phosphate catalysts
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Methods for coupling aryl halides or aryl sulfonates to produce biaryls or polyaryls using novel nickel phosphite catalysts are provided.
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- Use of ammonium aryl H-phosphonates in the preparation of nucleoside H-phosphonate building blocks
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Ammonium 4-methylphenyl H-phosphonate 4c was used in the conversion of 5'-0-(dimethoxy-trityl)-2'-deoxynucleoside derivatives 6 into the corresponding 3'-H-phosphonates 2, which were isolated in a high state of purity and in high yield.
- Ozola, Vita,Reese, Colin B.,Song, Quanlai
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p. 8621 - 8624
(2007/10/03)
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- ELECTROCHEMICALLY INDUCED PROCESSES OF FORMATION OF PHOSPHORUS ACID DERIVATIVES. 4. SYNTHESIS OF TRIALKYL PHOSPHATES FROM WHITE PHOSPHORUS
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The products of electrolysis in dipolar aprotic solvents on the background of tetraethylammonium iodide in the presence of white phosphorus are trialkyl phosphite (the primary product after splitting of all the P - P bonds in the phosphoric oligomers) and triaryl phosphate.It was found that the formation of triaryl phosphate from white phosphorus proceeds by way of electrochemical reduction of pentaaroxyphosphorane - an intermediate product of the reaction of triaryl phosphite with iodine and phenol.A strong dependence of the yields and distribution of the products on the composition of the electrolyte has been observed. Keywords: white phosphorus, electrosynthesis, triaryl phosphate.
- Budnikova, Yu. G.,Kargin, Yu. M.,Zaripov, I. M.,Romakhin, A. S.,Ignat'ev, Yu. A.,et al.
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p. 1585 - 1588
(2007/10/02)
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- Syntheses und NMR-Spektren phosphororganischer Antioxidantien und verwandter Verbindungen
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The syntheses of various aliphatic, aromatic, sterically hindered, and cyclic organophosphorus compounds (phosphorous acid esters, esters chlorides and ester amides, hydrogen phosphites, phosphinates and phosphates) are reported, and general procedures for preparation are given.The compounds synthesized were investigated by means of 31P-, 1H- and 13C-n.m.r. spectroscopy, and the chemical shifts measured are listed.
- Koenig, T.,Habicher, W.D.,Haehner, U.,Pionteck, J.,Rueger, C.,Schwetlick, K.
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p. 333 - 349
(2007/10/02)
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- The Mechanism of Nickel-Catalyzed Ethylene Hydrocyanation. Reductive Elimination by an Associative Process
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The complex (c2H4)L(CN)(C2H5)NiII has been identified at -40 deg C by 1H, 31P, and 13C NMR spectroscopy as the primary intermediate in the catalytic hydrocyanation of ethylene.Reaction of this intermediate with L causes reductive elimination of propanenitrile and produces (C2H4)L2Ni which reacts with ethylene and hydrogen cyanide to regenerate the intermediate.Measurements of second-order rate constants at -50 to -10 deg C result in ΔHexct=8.8 +/- 0.9 kcal/mol and ΔSexct=-34 +/- 4 eu (ΔGexct=16.7 +/- 0.1 kcal/mol at -40 deg C).At higher L concentrations, these nickel species are also in equilibrium with (C2H4)L3Ni, L4Ni, and HNi(CN)L3 which remove nickel from the productive catalytic cycle.Equilibrium constants relating these species and corresponding thermodynamic parameters have been determined.The rates of dissociation of L from L4Ni and HNi(CN)L3 have also been determined.The former reaction is very slow with ΔHexct=20.1 +/- 1.6 kcal/mol and ΔSexct=7 +/- 7 eu (ΔGexct=18.5 kcal/mol at -40 deg C) whereas the latter is about 1E3 faster with ΔHexct=18.8 +/- 2.7 kcal/mol and ΔSexct=17 +/- 10 eu (ΔGexct=14.8 kcal/mol at -40 deg C).
- McKinney, Ronald J.,Roe, D. Christopher
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p. 5167 - 5173
(2007/10/02)
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- Olefin complexes of nickel(0). 4. Equilibria in solutions containing P(O-o-tolyl)3 and cyanoolefins
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31P and 1H NMR and IR spectroscopy and spectrophotometry are used to demonstrate the presence of both olefin and nitrile complexes in solutions containing cyanoolefins, P(O-o-tol)3 (tol = tolyl), and nickel(0). Coordination of the olefinic double bond is favored by a terminal location and by conjugation with the nitrile group. Coordination of the nitrile nitrogen is favored by conjugation and by increased concentrations of free P(O-o-tol)3. A number of equilibrium constants and electronic spectra in benzene at 25 °C are reported and discussed in terms of the structures of the cyanoolefins.
- Tolman, Chadwick A.
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p. 614 - 621
(2008/10/08)
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- N-Phosphonomethyliminodiacetonitrile and certain derivatives thereof
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N-phosphonomethyliminodiacetonitrile and certain derivatives thereof are novel compounds which can be used as herbicides themselves and/or can be converted to known herbicides.
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