- Gas phase reaction of phosphorus trichloride and methanol: Matrix isolation infrared and DFT studies
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Abstract Gas phase reaction of phosphorus trichloride (PCl3) and methanol (CH3OH) was carried out with different ratios of PCl3:CH3OH:N2 (1:1:1000, 1:2:1000 and 1:3:1000) and the products were identified using matrix isolation infrared spectroscopy. For the 1:1 and 1:2 ratios of PCl3:CH3OH, dichloro methyl phosphite (DCMP) and methyl chloride (CH3Cl) were the products formed. Interestingly, only methyl chloride (CH3Cl) was observed for the 1:3 ratio of PCl3:CH3OH. DFT computations were carried out at B3LYP/6-311++G(d,p) level of theory to give insights into the formation of the reaction products. Based on the experimental findings and computations a reaction mechanism has been proposed through a nucleophilic substitution reaction to explain the formation of the products.
- Joshi, Prasad Ramesh,Ramanathan,Sundararajan,Sankaran
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Read Online
- Synthesis and properties of 4-(dibromomethyl)benzenecarbaldehyde
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4-(Dibromomethyl)benzenecarbaldehyde was synthesized for the first time using a new method which also allowed the co-preparation of terephthalic aldehyde. The reaction of this aldehyde with primary amines resulted in the formation of imines, including those containing an additional acetal group, while the reaction with trialkyl orthoformates led to the formation of acetals. The latter compounds were transformed into 4-(dibromomethyl)-substituted benzenes containing a phosphorus functional group in the side chain via consecutive reactions with phosphorus trichloride and the esters of P(III) acids.
- Gazizov, Mukattis B.,Ivanova, Svetlana Yu.,Bagauva, Liliya R.,Khairullin, Rafail A.,Musin, Rashid Z.
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supporting information
p. 210 - 212
(2015/12/31)
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- Synthesis of P-Stereogenic Phosphoramidite and Phosphorodiamidite Ligands and Their Application in Asymmetric Catalysis
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A series of P-stereogenic monodentate phosphoramidite (PNO2) and phosphorodiamidite (PN2O) ligands based on chiral Betti bases has been prepared by modular synthetic procedures. The chirality at the phosphorus can be controlled to a large extent by the synthetic route, leading to stereoselective access to single P-epimers. The absolute configuration of the P-atom was assigned by X-ray diffraction analysis. The new ligands were evaluated in asymmetric catalysis and the influence of the exocyclic amine or alcohol moiety as well as the interplay between the P-chirality and the stereocenters in the backbone were investigated. Enantioselectivities of up to 85 and 83 % ee were obtained in the Rh-catalyzed hydrogenation of dimethyl itaconate and in the Pd-catalyzed allylic amination of (rac)-(E)-1,3-diphenylallyl acetate with benzylamine, respectively. In the Ni-catalyzed hydrovinylation of styrene, ee values of up to 68 %, excellent chemoselectivities, and high activities (TOFav up to 3000 h-1) were achieved. A series of phosphoramidite (R = OR) and phosphorodiamidite (R = NR2) ligands containing a stereogenic phosphorus atom has been synthesized from chiral Betti bases as amino alcohol building blocks. The new ligands have been applied in three different asymmetric metal-catalyzed reactions, and the interplay between P-stereochemistry, structural features of R, and chirality at the backbone evaluated.
- Schmitz, Christian,Leitner, Walter,Franciò, Giancarlo
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p. 6205 - 6230
(2015/10/06)
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- CYCLIC NUCLEOTIDE ANALOGS
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Disclosed herein are cyclic nucleotide analogs, methods of synthesizing cyclic nucleotide analogs and methods of treating diseases and/or conditions such as viral infections, cancer, and/or parasitic diseases with cyclic nucleotide analogs.
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Page/Page column 58-59
(2012/07/13)
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- A general preparation of protected phosphoamino acids
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Fmoc-O-benzyl-l-phosphoserine is an important building block in the synthesis of Forigerimod, a phosphopeptide being investigated for Systemic Lupus Erythematosus (SLE). An efficient one-pot process was developed using inexpensive, readily available starting materials. This general procedure was used to prepare a variety of protected phosphoamino acids.
- Petrillo, Daniel E.,Mowrey, Dale R.,Allwein, Shawn P.,Bakale, Roger P.
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supporting information; experimental part
p. 1206 - 1209
(2012/05/04)
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- New approach to the synthesis of phosphorodichloridites, phosphorochloridites, and trialkyl phosphites
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Different trivalent organophosphorus esters such as phosphorodichloridites, phosphorochloridites, and mixed trialkyl phosphites have been easily synthesized in good yields using a HCl-catalyzed reaction of the corresponding chlorophosphine and alkoxytrimethylsilane by mutual exchange of the alkoxy and chlorine ligand pIIICl/ROSiR′3; exchange reaction). Chemoselectivity of the exchange reaction with primary and secondary alkoxytrimethylsilanes, as well as with alkoxytrimethylsilanes and thioalkoxytrimethylsilanes, respectively, has also been examined. It has been also found that the substitution reaction of chlorophosphines with secondary amine occurs more rapidly than the exchange reaction with ROSiR′ 3.
- Majewski, Piotr
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experimental part
p. 942 - 955
(2010/01/17)
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- First synthesis of etidronate partial amides starting from PCl3.
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Methods for the preparation of mixed tetra-amide esters 1 and 2, the partial amide ester 3, and tri- and P,P-diamides 4 and 5 from monophosphorus spieces 12, 8 and 9, respectively, were developed. Compounds 8 and 9 were obtained from phosphorus trichloride via MeOPCl2, which was treated with 2 eq. and 4 eq. of piperidine, followed by water or acetyl chloride, respectively. Tetrasubstituted amide bisphosphonates 1 and 2 were selectively dealkylated with lithium or silyl halide to achieve target compounds 3-5. Piperidine was found to be a good desilylation reagent. Quantum mechanical calculations illustrate why derivative 2 was produced in low yield. The usefulness of compounds 1, 3 and 4 as prodrugs of etidronate was determined in aqueous buffer and human serum.
- Turhanen, Petri A,Niemi, Riku,Peraekylae, Mikael,Jaervinen, Tomi,Vepsaelaeinen, Jouko J
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p. 3223 - 3226
(2007/10/03)
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- Hybridization of phosphate-methylated DNA and natural oligonucleotides. Implications for protein-induced DNA duplex destabilization
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Duplex stabilities have been determined for several hybrids of phosphate-methylated oligonucleotides and natural DNA or RNA using UV hyperchromicity experiments.These hybrids have a higher stability than the corresponding natural duplexes, due to the absence of interstrand electrostatic repulsions.Comparison with stability data for hybrids of other neutral oligonucleotides (with phosphate-ethylated and methyl phosphonate linkages) and natural DNA or RNA revealed that differences in stability could be attributed mainly to steric and stereoelectronic factors.For phosphate -ethylated oligonucleotides, hybridization with a natural strand is strongly influenced by steric interactions of the ethyl group.Hybridization with RNA, which requires a tight A-type conformation, is therefore difficult and the ethyl orientation (inward or outward, depending on the phosphorus configuration) determines the strength of the association with natural DNA.In methyl phosphonate systems, it appears that the presence of a P-C bond disturbs the helix conformation for stereoelectronic reasons.This leads to a weaker hybridization with DNA and RNA for longer strands.Phosphate-methylated oligonucleotides are found to have an optimal combination of steric and stereoelectronic factors and form the strongest hybrids with natural DNA.Absence of intrastrand phosphate-phosphate repulsions causes a slightly different comformation for phosphate-methylated DNA, which is evident in the cooperative character of the hybridization with natural DNA.A thermodynamic model for this cooperativity is presented and the model studies are extended to protein-DNA complexes in which phosphate charges are also shielded.The preliminary results suggest that protein association can destabilize a DNA duplex, thus providing a possible mechanism for the action of DNA unwinding enzymes.
- Genderen, Marcel H. P. van,Koole, Leo H.,Buck, Henk M.
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- THE PREPARATION OF DIMETHYL PHOSPHOROCHLORIDITE AND ITS HOMOLOGS FROM TRIALKYL PHOSPHITES AND DICHLOROTRIPHENYLPHOSPHORANE
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A novel convenient sythesis of dialkyl phosphorochloridites based on the reaction of trialkyl phosphites with dichlorotriphenylphosphorane has been described.In this way the commomly used dialkyl phosphorochloridites (3a-e) were prepared in satisfactory yields.Their identity was confirmed by 31P-NMR spectroscopy as well as by their refractive index.
- Majewski, Piotr
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- (2'--> 5')- and (3'--> 5')-Tubercidylyl-tubercidins - Synthesis via Phosphit Triester and Investigation of Secondary Structure
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The (2'--> 5')- and (3'--> 5')-linked dinucleoside monophosphates 3e and 2e of tubercidin were synthesized by condensation of the monomers 1c or 1b and 1a with dichloromethoxyphosphane.By 1H NMR studies it could be demonstrated that the conformation of these nucleobases is different from that in (3'--> 5')ApA and (2'--> 5')ApA.From thermodynamic parameters, as well as from hypochromicity, a stronger base-base interaction in 3e than in 2e was deduced.Single-strand specific nuclease S1 hydrolyses 2e at a much higher rate than (3'--> 5')ApA demonstrating that the enzyme is sensitive towards modification of the aglycone.Condensation of the 5'-deprotected dimer 3b with the monomer 1c followed by complete deprotection yields (2'--> 5')TupTupTu (4e), which is an analogue of (2'--> 5')ApApA, the triphosphate of which is antivirally active.
- Seela, Frank,Ott, Johann,Hissmann, Edith
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p. 692 - 707
(2007/10/02)
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- Preparation of O.S.-dimethyl phosphoroamidothioates
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O,S-dimethyl phosphoroamidothioates are prepared by reacting in the liquid phase methyl phosphorodichloridite with methyl sulfenyl chloride in the presence of a lower alkanoic acid to produce O,S-dimethyl phosphorochloridothioate and subsequently reacting in the liquid phase the O,S-dimethyl phosphorochloridothioate with ammonia or an amine.
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