- Synthesis of a polymerizable benzocyclobutene that undergoes ring-opening isomerization at reduced temperature
-
1-Ethoxyvinylbenzocyclobutene is a substituted benzocyclobutene that undergoes radical polymerization to produce polymers that can be crosslinked at 100-150 °C. The 4- and 5-vinyl isomers are synthesized in a 1:4 ratio via a halogenated benzyne intermediate produced from anthranilic acid, followed by cycloaddition with ethyl vinyl ether and replacement of the halogen atom with a vinyl group. Georg Thieme Verlag Stuttgart · New York.
- Pugh, Coleen,Baker, James S.,Storms, William K.
-
-
Read Online
- Substituted dienes prepared from betulinic acid – Synthesis, cytotoxicity, mechanism of action, and pharmacological parameters
-
A set of new substituted dienes were synthesized from betulinic acid by its oxidation to 30-oxobetulinic acid followed by the Wittig reaction. Cytotoxicity of all compounds was tested in vitro in eight cancer cell lines and two noncancer fibroblasts. Almost all dienes were more cytotoxic than betulinic acid. Compounds 4.22, 4.30, 4.33, 4.39 had IC50 below 5 μmol/L; 4.22 and 4.39 were selected for studies of the mechanism of action. Cell cycle analysis revealed an increase in the number of apoptotic cells at 5 × IC50 concentration, where activation of irreversible changes leading to cell death can be expected. Both 4.22 and 4.39 led to the accumulation of cells in the G0/G1 phase with partial inhibition of DNA/RNA synthesis at 1 × IC50 and almost complete inhibition at 5 × IC50. Interestingly, compound 4.39 at 5 × IC50 caused the accumulation of cells in the S phase. Higher concentrations of tested drugs probably inhibit more off-targets than lower concentrations. Mechanisms disrupting cellular metabolism can induce the accumulation of cells in the S phase. Both compounds 4.22 and 4.39 trigger selective apoptosis in cancer cells via intrinsic pathway, which we have demonstrated by changes in the expression of the crucial apoptosis-related protein. Pharmacological parameters of derivative 4.22 were superior to 4.39, therefore 4.22 was the finally selected candidate for the development of anticancer drug.
- ?arek, Jan,Benická, Sandra,D?ubák, Petr,Frydrych, Ivo,Gurská, Soňa,Hajdúch, Marián,Kotulová, Jana,Li?ková, Barbora,Olejníková, Denisa,Pokorny, Jan,Urban, Milan
-
-
- Visible Light Induced Cyclization to Spirobi[indene] Skeletons from Functionalized Alkylidienecyclopropanes
-
In this paper, we revealed a metal-free and visible light photoinduced method for the rapid construction of spirobi[indene] skeletons, providing a simple and efficient way for easy access to spirobi[indene] scaffolds under mild conditions along with a broad substrate scope and good functional group tolerance.
- Li, Quanzhe,Liu, Jiaxin,Shi, Min,Wei, Yin
-
supporting information
(2020/03/26)
-
- Organic phosphine salt and optical physical property regulation and control method and application thereof (by machine translation)
-
The invention discloses an organic phosphine salt and an optical physical property regulation and control method and application, of the compound, with different alkyl chain lengths through an ion exchange reaction; to obtain the organic phosphine salt, with different alkyl chain lengths through the ion exchange reaction to control the photophysical property (Cl, Br, I), of the compound by using alkyl, chain length and heavy atom, after, ultraviolet irradiation to achieve information, encryption application 300 nm. (by machine translation)
- -
-
Paragraph 0045-0053
(2020/05/30)
-
- Practical synthesis of phosphonium salts with orthoformates and their application as flame retardants in polycarbonate
-
An efficient and practical approach to phosphonium salts has been developed. By the reaction of phosphines and different acid sources with orthoformates in one-step operation, the process allowed rapid access to phosphonium salts with diverse counterions in high yield after the purification by recrystallization. The flame retardant performance in PC has also been examined by blending several phosphonium salts to PC respectively. Phosphonium phosphates showed excellent flame retardancy in PC with only 2 phr blending.
- Jiang, Pingkai,Li, Tao,Xu, Chencong,Zhang, Yong Jian
-
-
- Quaternary phosphonium salt flame retardant and synthesis method and application thereof
-
The invention provides a quaternary phosphonium salt flame retardant and a synthesis method and application thereof, and the method comprises the following steps: by taking an acidic compound, ortho-formic acid trisubstituted ester and an organic phosphine compound III or IV as raw materials, carrying out a one-step reaction process to prepare the quaternary phosphonium salt flame retardant I or II. The flame retardant disclosed by the invention has good thermal stability and has an excellent flame-retardant effect when being applied to various polymers. The method is simple and convenient insynthesis operation, low in raw material price, mild in synthesis condition and high in yield. According to the synthesis method, introduction of halogen ions is avoided, and dozens of anions are successfully introduced. By adding a small amount of the flame retardant, the obtained PC flame-retardant composite material UL-94 can reach the V-0 grade.
- -
-
Paragraph 0215-0219
(2020/06/20)
-
- Exploring an Umpolung strategy for quaternization of phosphorus
-
We propose a new, potentially widely-applicable, Umpolung approach for the synthesis of quaternary phosphonium salts R3PR1 X (X = Cl, Br) from phosphine oxides R3PO. The new organic group R1 is introduced via nucleophilic attack on an intermediate halophosphonium salt using a Grignard reagent R1MgX and replaces the traditional phosphine quaternization approach. Consequently, the new method does not suffer from the limited availability of many parent phosphines and is much faster than standard quaternization.
- Vetter, Anna C.,Nikitin, Kirill,Gilheany, Declan G.
-
p. 339 - 342
(2019/03/07)
-
- Iron-Nickel Dual-Catalysis: A New Engine for Olefin Functionalization and the Formation of Quaternary Centers
-
Alkene hydroarylation forms carbon-carbon bonds between two foundational building blocks of organic chemistry: olefins and aromatic rings. In the absence of electronic bias or directing groups, only the Friedel-Crafts reaction allows arenes to engage alkenes with Markovnikov selectivity to generate quaternary carbons. However, the intermediacy of carbocations precludes the use of electron-deficient arenes, including Lewis basic heterocycles. Here we report a highly Markovnikov-selective, dual-catalytic olefin hydroarylation that tolerates arenes and heteroarenes of any electronic character. Hydrogen atom transfer controls the formation of branched products and arene halogenation specifies attachment points on the aromatic ring. Mono-, di-, tri-, and tetra-substituted alkenes yield Markovnikov products including quaternary carbons within nonstrained rings.
- Green, Samantha A.,Vásquez-Céspedes, Suhelen,Shenvi, Ryan A.
-
supporting information
p. 11317 - 11324
(2018/09/18)
-
- Simplified Structural Mimetics of AIPS as Quorum Sensing Inhibitors
-
Compounds that regulate quorum sensing in Staphylococcal bacteria and in particular in Staphylococcus aureus are provided. Compounds are described in formulas I, II, III, IV, V and VI herein. One or more compounds herein can be employed to inhibit QS and to thus inhibit virulence in Staphylococcus bacteria and in particular in Staphylococcus aureus. Compounds herein and pharmaceutical compositions containing one or more of these compounds are useful, for example, in treating infections of Staphylococcus bacteria and in particular of Staphylococcus aureus. Methods for treating such bacterial infections are provided.
- -
-
Paragraph 0317
(2018/07/05)
-
- Synthesis method of resveratrol
-
The invention provides a synthesis method of resveratrol, and belongs to the technical field of natural product synthesis. The synthesis method comprises the following steps: with 3,5-dimethoxy benzoic acid as a raw material, generating 3,5-dimethoxy benzoyl chloride (12) through an acylating chlorination reaction; generating 3,5-dimethoxy benzamide (13) through an amidation reaction of the (12);generating 3,5-dimethoxyaniline (14) through a Hofmann degradation reaction of the (13); generating 3,5-dimethoxy iodobenzene (15) through a Sandmeyer reaction on the (14); generating 3,5,4'-trimethoxy diphenylethene (31) through a reaction between the (15) and p-methoxystyrene (23), and performing demethylation of the (31) to finally obtain resveratrol (1), wherein total yield is 23.3%. Accordingto the method, the adopted reagent is cheap and easily available, aftertreatment is simple, and two expensive intermediates for Heck reaction are synthesized by adopting cheap raw materials. A new synthesis method is provided for synthesizing resveratrol.
- -
-
Paragraph 0041; 0042
(2018/05/03)
-
- Frustrated Lewis Pair Chemistry with Magnesium Lewis Acids
-
Anilido imine–magnesium bromide complexes, (LHMgBr)2 and (LMeMgBr)2, have been prepared [LH = DIPP-N(C6H4)C(H)N-DIPP and LMe = DIPP-N(C6H4)C(Me)N-DIPP (DIPP = 2,6-iPr2C6H3)]. Their dimeric crystal structures are compared to the dimer (DIPP-nacnacMgBr)2 [DIPP-nacnac = DIPP-NC(Me)C(H)C(Me)N-DIPP]. The anilido imine ligands show some degree of charge delocalization but are clearly more asymmetric than the DIPP-nacnac complex: one of the N atoms has considerable anilido character, whereas the other one is close to an imine. Calculated natural population analysis (NPA) charges (B3PW91/6-311++G**) and an atoms-in-molecules (AIM) study on model systems quantify the asymmetry in charge distribution. Quantification of the Lewis acidity of LHMgBr and LMeMgBr by the Gutmann–Beckett test gave acceptor numbers of 58.9 and 58.3, respectively. The complexes themselves are inert to a number of electrophiles; however, in combination with PPh3 the substrate 1-butene oxide was ring-opened. The resulting betaine-type alkoxide complex is unstable and decomposes at room temperature through a Wittig-type reaction. At higher temperatures also a reverse Wittig-type decomposition is observed.
- Brand, Steffen,Pahl, Jürgen,Elsen, Holger,Harder, Sjoerd
-
p. 4187 - 4195
(2017/10/06)
-
- Synthesis and evaluation of novel tetrapropoxycalix[4]arene enones and cinnamates for protection from ultraviolet radiation
-
A series of novel calix[4]arene enones (5-7) and cinnamates (12-14) have been synthesized and evaluated for ensuring protection from ultraviolet radiation (UVR). Spectroscopic analyses has revealed that compound 6 absorbs ultraviolet radiations between 280 and 350 nm with an absorption maximum at 312 nm. Its molar absorption coefficient (ε) (>5 × 104 M-1 cm-1) and bandwidth are larger than those for the commercially used sun protectants (oxybenzone (OB), 2-ethylhexyl 4-methoxycinnamate (OMC) and avobenzone). The in vitro Sun Protection Factor (SPF) measurement revealed an SPF of 5.2 at 2% concentration of 6 in home made emulsion formulations while combination of 2% each of 6 and OMC gave an SPF of 8.8. Lower sun protection seems to be compensated by significant protection from more harmful UVA radiations (UVA/UVB absorbance ratio of 0.62).
- Chawla,Pant, Nalin,Kumar, Satish,Mrig, Sarika,Srivastava, Bindu,Kumar, Naresh,Black, D. Stc.
-
body text
p. 25 - 33
(2012/05/05)
-
- Thermogravimetrical investigations of the dealkoxycarbonylation of N-acyl-α-triphenylphosphonioglycinates
-
Thermogravimetrical experiments revealed that immediately after the endothermic process of the melting of N-acyl-α- triphenylphosphonioglycinates 1, an exothermic demethoxycarbonylation of phosphonioglycinates commenced, accompanied by the release of CO2. The residues contained the corresponding N-acylaminomethyltriphenylphosphonium salts 2 (18.3-49.5%), methyltriphenylphosphonium salts 7 (21.8-67.9%), and the corresponding 1,2-di(N-acylamino)fumaric acid dimethyl ester 6 (2.1-26.0%). When the reaction was carried out in the presence of Ph3P and the corresponding triphenylphosphine hydrobromide, hydroiodide, or tetrafluoroborate, N-acyl-α-triphenylphosphoniumglycinate bromides and iodides 1a-f underwent demethoxycarbonylation to form the corresponding N-acylaminomethyltriphenylphosphonium salts 2a-f at 95-130 °C in good to excellent yields (79-100%). On the other hand, tetrafluoroborates 1g-i underwent corresponding reactions at about 170-175 °C to give phosphonium tetrafluoroborates 2g-i in much lower yields (34-67%). Plausible mechanisms of the investigated reaction are discussed. It was also demonstrated that the obtained crude α-(N-acylamino)alkyltriphenylphosphonium salts 2 could be applied as valuable α-amidoalkylating agents in spite of their contamination with inert methyltriphenylphosphonium salts 7.
- Adamek, Jakub,Mrowiec-Bia?on?, Julita,Pa?dzierniok-Holewa, Agnieszka,Mazurkiewicz, Roman
-
experimental part
p. 22 - 27
(2011/02/26)
-
- Dichotomous reactivity in the reaction of triethyl- and triphenylphosphane HBr salts with dimethyl acetals: A novel entry to α-alkoxy-functionalized ylides and general synthesis of vinyl ethers and alkoxy dienes
-
The discovery of dichotomous reactivity in the reaction of trialkyl- vs. triphenylphosphane HBr salts with acetals allows entry to functionalized α-methoxy phosphonium salts and a novel process for tertiary phosphane methylation. The new protocol opens a general entry to the synthesis of vinyl ethers and differentially substituted 1,3-dienes via Wittig reactions of the functionalized ylides derived from the α-methoxy phosphonium salts.
- Das, Priyabrata,McNulty, James
-
supporting information; experimental part
p. 3587 - 3591
(2010/09/05)
-
- Thermal decomposition of triphenylphosphonium alkyl ester salts
-
In thermolyses of molten triphenylphosphonium alkyl ester bromides and chlorides, alkyl = methyl, ethyl, isopropyl, at 130 and 225°C, initial attack of the halide ion on the methyl group gives the methyl halide and ylid 1, Ph3P = CH2, which can be methylated, or is protonated by the phosphonium salt with transylidation giving Ph3P+-CH3X-, X = Br, Cl. The initial reactions of the ethyl or isopropyl esters are with the halide ion, X-, as a base giving ylid, 1, which can be protonated by HX or by transylidation. The t-butyl ester generates Ph3P+-CH3X-but no products of transylidation. The first-formed ylid1, can be trapped by reactive alkyl and acyl halides, and the transient ylidic esters decompose thermally to triphenyl phosphine oxide, Ph3P = O, react further with unreacted phosphonium ester, or are trapped by added aldehyde in a Wittig reaction. The final product compositions are affected by a decrease in pressure, due to escape of volatile intermediates, and by replacement of the X- halide ion by the less nucleophilic and basic tosylate ion. Reactions under reflux, in solution in chloroform, or in suspension in benzene, are similar to those of the molten salts, but yields are generally lower at the lower temperatures. Copyright Taylor & Francis Group, LLC.
- Castaneda, Fernando,Aliaga, Christian,Acuna, Cristina,Silva, Paul,Bunton, Clifford A.
-
experimental part
p. 1188 - 1208
(2009/04/16)
-
- A practical synthesis of chiral and achiral phosphonium salts from phosphine borane complexes
-
Phosphine borane complexes are transformed under mild conditions, in presence of an olefin, into quaternary phosphonium salts by reaction with an alkyl (or aryl) halide. In the case of the reaction of (R)-PAMP.BH3 1e with benzyl bromide, the enantiomerically pure phosphonium salt 3h is obtained.
- Uziel, Jacques,Riegel, Nadege,Aka, Benoit,Figuiere, Pierre,Juge, Sylvain
-
p. 3405 - 3408
(2007/10/03)
-
- PROTEASE-BINDING COMPOUNDS AND METHODS OF USE
-
Non-peptide, protease-binding compounds are described as useful in the detection, labelling, and inhibition of retroviral proteases. Aryl piperidinyl derivatives and other compounds related in structure have been found to be HIV-1 and HIV-2 protease-binding compounds.
- -
-
-
- 4,5-bridged-2,3,4,5-tetrahydro-1H-3-benzazepine-7-ols and derivatives and compositions and methods employing such compounds
-
Novel benzazepines of the formula I: STR1 or a pharmaceutically acceptable salt thereof, wherein R represents H, alkyl, allyl or STR2 A represents --[CR1 R2]n --; n represents 3 or 4; R1 and R2 may be the same or different and each independently represents H, OH, atkyl, alkoxy, phnenyl or substituted phenyl, with the proviso that R1 and R2 on the same carbon atom are not both OH, or R1 and R2 on the same carbon atom together represent=O; G represents H, R3 (CO)-- or ArNHCO--; R3 represents H, alkyl, alkoxy, phenyl or substituted phenyl; Ar represents phenyl or substituted phenyl; and Y and Z may be the same or different and each is independently selected from H, halo, alkyl, alkoxy or halpalkyl; the pharmaceutically acceptable salts thereof, and pharmaceutical compositions thereof, useful in the treatment of psychoses, drug dependence, D1 dependent neurological disorder or pain are disclosed.
- -
-
-
- Synthesis of Chiral Vinylglycines
-
(R)- or (S)-benzyl 4-formyl-2,2-dimethyl-3-oxazolidinecarboxylate (7a) and (R)- or (S)-1,1-dimethylethyl 4-formyl-2,2-dimethyl-3-oxazolidinecarboxylate (7b), readily available from serine, react with Wittig reagents to give alkenes 8.Selective deprotection followed by oxidation of the resulting unsaturated amino alcohols 9 provides vinylglycines 5 of defined configuration (>95percent ee) and double-bond geometry.D-Vinylglycines are obtained from L-serine, and conversely, D-serine gives β,γ-unsaturated amino acids with the L configuration.The double-bond geometry is controlled by the nature of the phosphorous ylide employed.The scope and limitations of this new methodology for the preparation of chiral vinylglycines is examined.
- Beaulieu, Pierre L.,Duceppe, Jean-Simon,Johnson, Carolyne
-
p. 4196 - 4204
(2007/10/02)
-
- A CONVENIENT SYNTHESIS OF ALKYLPHOSPHONIUM SALTS
-
The reaction of methanol and its homologs with Ph3P in 48percent aqueous hydrobromic acid provides alkyltriphenylphosphonium salts in quantitative yields.
- Hercouet, A.,Corre, M. le
-
p. 279 - 280
(2007/10/02)
-
- Reaction des oxirannes avec la triphenylphosphine en milieu phenolique
-
A new access to the vinylphosphonium salts 4 is proposed, using the reaction of epoxides 1 with triphenylphosphine at 100 deg C in phenol.It succeeds very well for the unfunctional epoxides 1 : 2-monosubstituted and 2,3-disubstituted epoxides.In the case of arylepoxides and 2,2-disubstituted unfunctional epoxides, Wittig and " retro-Wittig " side-reactions decrease the yields in vinylphosphonium salts.The reaction of opening epoxides by triphenylphosphine takes place since 40 deg C and is regio and stereoselective.At 40 deg C, the reaction leads to the formation of β-hydroxy alkylphosphonium salts 3.
- Christol, Henri,Grelet, Danielle,Darvich, Mohammad Raouf,Fallouh, Fayez,Plenat, Francoise,Cristau, Henri-Jean
-
p. 477 - 483
(2007/10/02)
-
- NOVEL REACTIONS OF PHOSPHONIUM YLIDES WITH PERHALOALKANES: FIRST EXAMPLES OF HALOPHILIC ATTACKS BY PHOSPHONIUM YLIDES AND A FACILE ROUTE TO α-HALOALKYLPHOSPHONIUM SALTS
-
Phosphonium ylides Ph3=CHR (R = H, CH3, C2H5, n-C3H7, n-C5H11) react readily with perhalofluoroalkanes to afford regiospecifically α-haloalkylphosphonium salts Ph3P+-CHXR Y- (X = I, Br, Cl) in good yields.These reactions reveal a new type of reactivity phosphonium ylides, i.e., the halophilic attack on C-X bonds, and may be useful for the regiospecific synthesis of substituted haloolefins via Wittig reaction.
- Li, Xing-Ya,Hu, Jin-Shan
-
p. 6317 - 6320
(2007/10/02)
-
- Studies on the Synthesis of Linear Aliphatic Compounds. Part. 3. The Synthesis of Paraffins with Very Long Chains
-
The approach derived in Part 2 has been modified to increase the purity and yield of intermediates.The C12 starting materials have been doubled in chain length five times, and by using components of similar or different chain length in Wittig condensations ω-halogeno-acetals with 12n carbon atoms have been made up with n up to 32.They have been converted into paraffins with 102, 104, 150, 198, 246, 294, and 390 carbon atoms.Those paraffins with 150 or more carbon atoms show chain-folding in the crystalline state; this observation is contributing to the understanding of chain-folding behaviour long known in linear polyethylene but hitherto unknown in essentially pure paraffins.
- Bidd, Ilesh,Holdup, David W.,Whiting, Mark C.
-
p. 2455 - 2464
(2007/10/02)
-
- Synthesis of (E)- and (Z)-Pulvinones
-
Two new routes to pulvinones have been developed, one of which involves a novel Wittig reaction.For the first time, members of the E-series, including the parent (E)-pulvinone, are reported and the structural elucidation of the geometric isomers is descri
- Campbell, Alexander C.,Maidment, Maurice S.,Pick, John H.,Stevenson, Donald F. M.
-
p. 1567 - 1576
(2007/10/02)
-
- REACTION OF ARACYL- AND ALKOXYCARBONYLMETHYLSELENONIUM SALTS WITH NUCLEOPHILIC REAGENTS
-
A method is proposed for the synthesis of α-methylselenium derivatives of aryl and heteryl methyl ketones and ethyl acetate by demethylation of readily available aracyl-, heteroacyl-, and methoxycarbonylmethylselenonium salts with triethylamine.It was established that triphenylphosphine cleaves dimethylphenacylselenonium bromide both at the Se-methyl and at the Se-CH2COPh bond (preferentially).Triphenylphosphine selenide is formed in this reaction in addition to the corresponding phosphonium salts.
- Magdesieva, N. N.,Kyandzhetsian, R. A.,Kirpichenok, M. A.,Chovnikova, N. G.
-
p. 2279 - 2284
(2007/10/02)
-
- Deuterium Isotope Effects for Migrating and Nonmigrating Groups in the Solvolysis of Neopentyl-Type Esters
-
α- and γ-deuterium rate effects on the solvolysis of (1-methylcyclohexyl)methyl, (1-methylcyclopentyl)methyl, and (1-methylcyclobutyl)methyl sulfonate esters have been measured and the solvolysis products examined by 2H NMR spectroscopy.The results indicate that the products of the solvolysis of all these sulfonate esters are predominantely ((*) 98percent) rearranged.In the solvolysis of (1-methylcyclohexyl)methyl triflate, rearranged products with methyl migration slightly dominate over those with ring expansion.Normal isotope effects, 1.057 in 80E and 1.073 in 97T, are observed for the methyl-d3 compound and an inverse effect, 0,963, is observed in 80E for the methylene-d4 compound.However, in the solvolysis of both (1-methylcyclopentyl)methyl and (1-methylcyclobutyl)methyl sulfonates, the major products are those of ring expansion.In these examples, inverse effects are observed for the methyl-d3-labeled species.The observed isotope effects can be separated into respective values of 0.927, 0.913 for the nonmigrating methyl-d3 group and 1.177, 1.224 for the migrating methyl-d3 group in the solvolysis of (1-methylcyclohexyl)methyl triflate and (1-methylcyclopentyl)methyl brosylate.This explains the relative intramolecular migratory aptitudes of CH3/CD3 of 1.20 - 1.30 and the low γ-d9 isotope effect in the solvolysis of neopentyl sulfonates previously reported and makes them consistent with a mechanism which involves neighboring carbon participation during ionization.
- Shiner, V. J.,Tai, Jimmy J.
-
p. 436 - 442
(2007/10/02)
-
- Diphenyl compounds that are intermediates in preparation of polymerization initiators
-
Organo-lithium compounds of the formula: STR1 wherein R is an alkyl group of up to 5 carbon atoms, R' is either hydrogen or an alkyl group of up to 5 carbon atoms and n is an integer from 2 to 10. These bifunctional organo-lithium compounds are prepared w
- -
-
-
- Bi-and trifunctional organolithium initiators
-
New organo-lithium initiators, their synthesis, and their use. The initiators have the formula: STR1 IN WHICH R" is either a hydrogen atom or a methyl radial; either n is 1, in which case R' = H and m and p are integers, the sum of which is between 0 and
- -
-
-
- Mercaptoalkylpyridine disulfides
-
Mercaptoalkylpyridines carrying an ethenyl or ethynyl substituent are prepared from known pyridine compounds, principally pyridoxine, by known chemical procedures, and are useful in the treatment of rheumatoid arthritis and related inflammatory diseases.
- -
-
-
