cas 4736-60-1, Ethyltriphenylphosphonium iodide

Articles about 4736-60-1Total 27 be found

Article title
Article abstract
Author
Journal number and time
Download

Enzymatic Synthesis of Methylated Terpene Analogues Using the Plasticity of Bacterial Terpene Synthases
Methylated analogues of isopentenyl diphosphate were synthesised and enzymatically incorporated into methylated terpenes. A detailed stereochemical analysis of the obtained products is presented. The methylated terpene precursors were also used in conjunction with various isotopic labellings to gain insights into the mechanisms of their enzymatic formation.
Dickschat, Jeroen S.,Hou, Anwei,Lauterbach, Lukas
(2020)
Read Online

Quaternary Phosphorus-Induced Iodocuprate(I)-Based Hybrids: Water Stabilities, Tunable Luminescence and Photocurrent Responses
Four (triphenyl)phosphonium-based quaternary phosphorus salts with different substituents (varying from methyl to n-butyl) were selected to be structural directed agents (SDAs) to construct four iodocuprate(I) hybrids via solution method, i.e., [(PPh3Me)(Cu3I4)]n (1), [(PPh3Et)(Cu3I4)]n (2), (PPh3iPr)2(Cu2I4) (3), [(PPh3nBu)(Cu3I4)]n (4). The inorganic iodocuprates in 1, 2 and 4 are 1-D (Cu3I4)nn– chains constructed from Cu5I11 units, but (Cu2I4)2– in 3 is a di-nuclear cluster. Interestingly, the strength of Cu···Cu and π–π stacking interactions are weakened with the lengthening of alkyl groups on P-atom. The best water stability of 4 can be ascribed to the better hydrophobicity of n-butyl group, which deters the dispersing of organic and inorganic moieties and as a result, inhibit hydrolysis reaction. Furthermore, all compounds exhibit typical reversible luminescent thermochromic behaviors, among which 4 exhibits blue emission and the quenching of higher energy (HE) zone in 1 and 2 are led by strong π–π stacking interactions. Besides, effective and repeatable photocurrent responses can be detected in these compounds. In all, by systematically introducing alkyl groups into (triphenyl)phosphonium as SDAs to prepare hybrid iodocuprates, we can find that the longer alkyl groups can achieve stronger tunable PL materials with enhanced water stabilities.
Zhang, Wen-Ting,Liu, Jian-Zhi,Liu, Jing-Bo,Song, Kai-Yue,Li, Yi,Chen, Zhi-Rong,Li, Hao-Hong,Jiang, Rong
supporting information
p. 4234 - 4244
(2018/10/15)

Enantioselective palladium-catalyzed addition of malonates to 3,3-difluoropropenes
Monofluoroalkenes bearing a malonate unit at the β position can be synthesized by the enantioselective addition of diesters to 3,3-difluoropropenes. The difference in reactivity regarding the geometry and the substituents of the alkene of the 3,3-difluoropropenes, as well as the alkyl groups of the malonates, was studied and limitations were identified. The reaction was also performed with different 3,3-difluoropropenes. Further synthetic transformations of a newly functionalized monofluoroalkene were also accomplished.
Drouin, Myriam,Paquin, Jean-Fran?ois
supporting information
p. 6023 - 6032
(2018/09/11)

(E)-Selective Wittig Reactions between a Nonstabilized Phosphonium Ylide Bearing a Phosphastibatriptycene Skeleton and Benzaldehydes
Wittig reactions between benzaldehyde derivatives and a nonstabilized phosphonium ylide bearing a phosphastibatriptycene skeleton, regarded as a tridentate aryl ligand, gave (E)-alkenes with high selectivity in the presence of both lithium and sodium salts. As previously reported, reactions between a triphenylphosphonium ylide and benzaldehyde derivatives under the same conditions afforded mainly (Z)-alkenes. Variable-temperature (VT)31P{1H} NMR spectra showed two signals, assigned to cis- and trans-1,2-oxaphosphetanes, which were observed at different temperatures (–80 °C and –40 °C, respectively) in the Wittig reaction between benzaldehyde and the nonstabilized phosphonium ylide bearing the phosphastibatriptycene skeleton, in the presence of both lithium and sodium salts, and showed the existence of equilibrium between these products at –40 °C. On the other hand, this equilibrium was not clearly observed in the reaction between the triphenylphosphonium ylide and benzaldehyde, for which only one signal was detected. The observed intermediates were confirmed to be 1,2-oxaphosphetanes by deprotonation of the isolated β-hydroxyalkylphosphonium salts bearing a phosphastibatriptycene skeleton and a triphenylphosphine moiety, respectively. Crossover reactions were conducted in the deprotonations of β-hydroxyalkylphosphonium salts with TMS2NNa in the presence of p-chlorobenzaldehyde, resulting in the observation of signals corresponding to 1,2-oxaphosphetanes containing phenyl and p-chlorophenyl groups at the 4-positions, indicating the exchange process between benzaldehyde and p-chlorobenzaldehyde at –40 °C for the phosphastibatriptycene system and at 0 °C for triphenyl derivatives. These results clearly indicated that stereochemical drift occurred at those temperatures, even in reactions using nonstabilized phosphonium ylides. The stereochemical drift in the phosphastibatriptycene system occurred at a lower temperature than in the case of the triphenyl derivative, thus explaining the (E)-selective Wittig reactions between the benzaldehyde derivatives and the nonstabilized phosphastibatriptycene-based phosphonium ylide in the presence of lithium and sodium salts.
Uchiyama, Yosuke,Ohtsuki, Takemaru,Murakami, Rikiya,Shibata, Munenori,Sugimoto, Jun
p. 159 - 174
(2017/01/14)

Design, synthesis and SAR study of novel sulfonylureas containing an alkenyl moiety
A series of sulfonylurea compounds was designed and synthesized via introducing an alkenyl moiety into the aryl-5 position and most title compounds exhibited enhanced antifungal activities and limited herbicidal activities compared with chlorsulfuron. Then, a CoMSIA calculation for antifungal activities was carried out to establish a 3D-QSAR model in which a cross-validated q2 of 0.585 and a correlation coefficient r2 of 0.989 were obtained. The derived model revealed that hydrophobic and electrostatic fields were the two most important factors for antifungal activity. Structure optimization was performed according to the CoMSIA model and compound 9z was found to be as potent as chlorothalonil in vitro against C. cornigerum, the pathogen of the wheat sharp eyespot disease. In order to study the fungicidal mechanism, 9z was successfully docked into yeast AHAS using a flexible molecular docking method and the resulting binding pattern was similar to that of chlorimuron-ethyl, indicating that the antifungal activity of compounds 9 was probably due to the inhibition of fungal AHAS.
Wei, Wei,Cheng, Dandan,Liu, Jingbo,Li, Yuxin,Ma, Yi,Li, Yonghong,Yu, Shujing,Zhang, Xiao,Li, Zhengming
p. 8356 - 8366
(2016/09/09)

A transition-metal-free Heck-type reaction between alkenes and alkyl iodides enabled by light in water
A transition-metal-free coupling protocol between various alkenes and non-activated alkyl iodides has been developed by using photoenergy in water for the first time. Under UV irradiation and basic aqueous conditions, various alkenes efficiently couple with a wide range of non-activated alkyl iodides. A tentative mechanism, which involves an atom transfer radical addition process, for the coupling is proposed.
Liu, Wenbo,Li, Lu,Chen, Zhengwang,Li, Chao-Jun
supporting information
p. 6170 - 6174
(2015/06/08)

New methodology for the conversion of epoxides to alkenes
Epoxides have been transformed in good yields to alkenes by a process involving (i) ring-opening of the epoxide with 2-mercaptobenzothiazole, (ii) oxidation of the derived ss-hydroxy thioethers to the corresponding sulfones, and (iii) thermal or base-promoted fragmentation of these sulfones to alkenes. The stereochemistry of the starting epoxide is transfer-red faithfully to the alkene product, because of the SN2 epoxide ring-opening reactions and the antiperiplanar SO2 elimination reaction of the ss- alkoxysulfinate intermediates. This methodology may form the basis of a new protecting group strategy for alkenes.
Wu, Feng-Ling,Ross, Benjamin P.,McGeary, Ross P.
experimental part
p. 1989 - 1998
(2010/06/15)

Highly selective iridium-catalyzed asymmetric hydrogenation of trifluoromethyl olefins: A new route to trifluoromethyl-bearing stereocenters
Fluorine-containing compounds are useful in many applications ranging from pharmaceuticals to ferroelectric crystals. We have developed a new, highly enantioselective synthetic route to trifluoromethyl-bearing stereocenters in up to 96% ee via asymmetric hydrogenation using N,P-ligated iridium catalysts. We also hydrogenated an isomeric mixture of olefins; this reaction gave the hydrogenation product highly enantioselectively (87% ee), and only the E isomer was present after the reaction had reached 56% conversion.
Engman, Mattias,Cheruku, Pradeep,Tolstoy, Paeivi,Bergquist, Jonas,Voelker, Sebastian F.,Andersson, Pher G.
supporting information; experimental part
p. 375 - 378
(2009/11/30)

Iridium-catalyzed asymmetric hydrogenation yielding chiral diarylmethines with weakly coordinating or noncoordinating substituents
Diarylmethine-containing stereocenters are present in pharmaceuticals and natural products, making the synthetic methods that form these chiral centers are important in industry. We have applied iridium complexes with novel N,P-chelating ligands to the asymmetric hydrogenation of trisubstituted olefins, forming diarylmethine chiral centers in high conversions and excellent enantioselectivities (up to 99% ee) for a broad range of substrates. Our results support the hypothesis that steric hindrance in one specific area of the catalyst is playing a key role in stereoselection, as the hydrogenation of substrates differing little at the prochiral carbon occurred with high enantioselectivity. As a result, excellent stereodiscrimination was obtained even when the prochiral carbon bore, for example, phenyl and p-tolyl groups.
Tolstoy, Paeivi,Engman, Mattias,Paptchikhine, Alexander,Bergquist, Jonas,Church, Tamara L.,Leung, Abby W.-M.,Andersson, Pher G.
supporting information; experimental part
p. 8855 - 8860
(2009/12/04)

Synthesis of the deuterated sex pheromone components of the grape borer, xylotrechus pyrrhoderus
Adult males of the grape borer, Xylotrechus pyrrho- derus, secrete (S)-2-hydroxy-3-octanone [(S)-1] and (2S,3S)-2,3-octanediol [(2S,3S)-2] from their nota of prothoraces as sex pheromone components. Their structural similarity suggests that one of them is the biosynthetic precursor of the other component. In order to confirm the biochemical conversion, deuterated derivatives of both components were synthesized by starting from a Wittig reaction between hexanal and an ylide derived from D5-iodoethane and ending with enantiomeric resolution by chiral HPLC. The molecular ions of 1 and 2 could scarcely be detected by using a GC- MS analysis, and the labeled compounds showed similar mass spectra to the unlabeled pheromone components. However, several fragment ions, including four deuterium atoms, were observed in the mass spectra of their acetate derivatives, indicating that the conversion could be confirmed by examining a compound with the diagnostic ions after acetylation of the volatiles collected from insects treated with the labeled precursors.
Kiyota, Ryutaro,Yamakawa, Rei,Iwabuchi, Kikuo,Hoshino, Keita,Ando, Tetsu
experimental part
p. 2252 - 2256
(2010/08/03)

The cyclopropyl group as a hypersensitive probe in the singlet oxygen ene reaction mechanism
(Chemical Equation Presented) Cyclopropyl-substituted olefins are employed as mechanistic probes in the singlet oxygen-alkene ene reaction. In MeOH and aprotic solvents [CHCl3, (CH3)2CO, CH 3CN], only the allylic hydroperoxides bearing an intact cyclopropyl group are detected. The reaction mechanism is independent of solvent polarity. Our findings, to a certain experimental limit, exclude a biradical or dipolar intermediate.
Alberti, Mariza N.,Orfanopoulos, Michael
supporting information; experimental part
p. 2465 - 2468
(2009/05/27)

Solvent-dependent changes in the ene reaction of RTAD with alkenes: The cyclopropyl group as a mechanistic probe
(Chemical Equation Presented) The vinylcyclopropyl moiety was used as an efficient probe to test mechanistic possibilities of the triazolinedione-alkene ene reaction. In non-hydroxylic solvents, this reaction afforded only the ene adducts via a closed three-membered aziridinium imide (Al) intermediate, whereas in hydroxylic solvents a dipolar intermediate is favored and trapped by the cyclopropyl moiety to form the corresponding cyclopropyl-rearranged solvent-trapped adducts.
Roubelakis, Manolis M.,Vougioukalakis, Georgios C.,Angelis, Yiannis S.,Orfanopoulos, Michael
p. 39 - 42
(2007/10/03)

Electronic properties of furyl substituents at phosphorus and their influence on 31P NMR chemical shifts
The electronic properties of 2-furyl and 3-furyl substituents attached to phosphanes and phosphonium salts were studied by means of IR spectroscopy and experimental and computational 31P NMR spectroscopy. The heteroaromatic systems proved to be electron withdrawing with respect to phenyl substituents. However, phosphorus atoms with attached furyl substituents are strongly shielded in NMR. The reason for this phenomenon was studied by solid state 31P MAS NMR experiments. The chemical shift tensor was extracted, and the orientation within the molecules was determined. The tensor component σ33, which is effected the most by furyl systems, is oriented perpendicular to the P-C bonds of the substituents. P-furyl bonds are shorter than P-phenyl bonds. We assume therefore a lower ground-state energy of the molecules, because of the electron withdrawing properties of the 2-furyl systems. The σpara component of the 31P NMR magnetic shielding is therefore smaller, which results in an overall increase of the magnetic shielding.
Ackermann, Marco,Pascariu, Aurelia,Hoecher, Thomas,Siehl, Hans-Ullrich,Berger, Stefan
p. 8434 - 8440
(2007/10/03)

A Wittig reaction with 2-furyl substituents at the phosphorus atom: Improved (Z) selectivity and isolation of a stable oxaphosphetane intermediate
Wittig reactions with ylides bearing one, two or three 2-furyl groups directly bound to the phosphorus atom have been studied. Greatly improved (Z)-alkene selectivities of up to 98:2 could be observed if 2-furyl groups were present. Monitoring of the reactions by NMR spectroscopy revealed only oxaphosphetane intermediates, which became more stable with increasing number of 2-furyl substituents bound to the phosphorus atom. Oxaphosphetane 10d, with three furyl groups, was successfully isolated, and the results of a crystal structure analysis are presented. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
Appel, Marco,Blaurock, Steffen,Berger, Stefan
p. 1143 - 1148
(2007/10/03)

Attempt to approach the role of phenolic phenylpropenol structures in the photoyellowing of softwood mechanical pulps
Three biphenyl (I, II, III) compounds and a benzylarylether (IV) compound were synthesized to detect and quantify the presence of phenolic phenylpropenols in unbleached, peroxide-bleached, or sodium borohydride-reduced mechanical softwood pulps. The methodology used is based on a gas chromatography - mass spectrometry search of the prepared compounds in the residue obtained after ethylation, thioacidolysis, and desulfurization of the pulps. Detection of biphenyl I (≈4 × 10-6 mol g-1) in unbleached and NaBH4-reduced pulps is indicative of the presence of phenolic coniferaldehyde units in these pulps. Traces of biphenyl II, found in the peroxide-bleached pulp, probably came from ferulic acid units formed by oxidation of coniferaldehyde by H2O2. No biphenyl ether III or benzylaryl ether IV were detected in the three pulps. This result indicates that phenolic phenylpropenol units are not present in softwood mechanical pulps and do not contribute to the fast part of their photoyellowing.
Ruffin, Brigitte,Grelier, Stephane,Nourmamode, Aziz,Castellan, Alain
p. 1223 - 1231
(2007/10/03)

Microwave irradiation in organophosphorus chemistry. Part 2: Synthesis of phosphonium salts
Several phosphonium salts have been prepared using a domestic microwave oven. The microwave enhanced reaction of triphenylphosphine and an organic halide shows a remarkable rate acceleration under microwave irradiation and allows the general and facile synthesis of both stabilized and non-stabilized phosphonium salts. (C) 2000 Elsevier Science Ltd.
Kiddle, James J.
p. 1339 - 1341
(2007/10/03)

A Dynamic Equilibrium of Oxaphosphetanes
The course of the Wittig reaction was investigated by rapid injection NMR spectroscopy.Rate constants for the formation of oxaphosphetanes were determined.A new dynamic equilibrium of oxaphosphetanes was observed for the first time.The solvent and substituent dependence of the new effect was investigated.By labeling various oxaphosphetanes with 13C and 17O the lithium salt dependence of the new equilibrium was shown.A lithium adduct of oxaphosphetanes under these conditions is proposed. - Key Words: Wittig reaction / Rapid injection NMR / Dynamic NMR / Oxaphosphetanes
Geletneky, Christian,Foersterling, Frank-Holger,Bock, Willi,Berger, Stefan
p. 2397 - 2402
(2007/10/02)

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)

Synthesis, Structure, and Reactivity of Stable Alkyl and Aryl Iodide Complexes of the Formula 5-C5H5)Re(NO)(PPh3)(IR)>(1+)BF4(1-)
Reaction of methyl complex (η5-C5H5)Re(NO)(PPh3)(CH3) with HBF4*Et2O (CH2Cl2, -78 deg C) and then alkyl and aryl iodides RI gives adducts 5-C5H5)Re(NO)(PPh3)(IR)>(1+)BF4(1-) (3: R = a, CH3; b, CH2CH3; c, CH2CH2CH3; d, CH2CH2CH2CH3; e, CH2Si(CH3)3; f, CH2CH2CH2Cl; g, CH2Cl; h, C6H5; i, p-C6H4OCH3; 63-87percent).The structure of 3e*(CH2Cl2)0.5 is confirmed by X-ray crystallography and compared to that of iodide complex (η5-C5H4CH3)Re(NO)(PPh3)(I) .The C-I bond is not significantly longer than those in free alkyl iodides.Complexes 3a-c decompose (48-60 h, CD2Cl2, 25 deg C) to bridging halide complexes (SS,RR)-5-C5H5)Re(NO)(PPh3)>2X(1+)BF4(1-) and react with CH3CN to give acetonitrile complex 5-C5H5)Re(NO)(PPh3)(NCCH3)>(1+)BF4(1-) (82-87percent) and RI (72-82percent).Complexes 3a-c rapidly alkylate PPh3 (5-C5H5)Re(NO)(PPh3)(I) (>99-92percent).The reaction of 3b and PPh3 is second order (ΔH(excit.) = 12.9 +/- 0.6 kcal/mol, ΔS(excit.) = -12.0 +/- 0.9 eu) and (3.3 +/- 1.3) x 1E5 faster (298 K) than that of ICH2CH3 and PPh3 to give Ph3PCH2CH3(1+)I(1-) (ΔH(excit.) = 16.3 +/- 0.4 kcal/mol, ΔS(excit.) = -25.9 +/- 1.5 eu).Complex 3b reacts similarly with Br(1-), but 3h yields IC6H5 and (η5-C5H5)Re(NO)(PPh3)(Br).Ethyl bromide and chloride complexes analogous to 3b are less stable but can be prepared in situ.
Winter, Charles H.,Veal, William R.,Garner, Charles M.,Arif, Atta M.,Gladysz, J. A.
p. 4766 - 4776
(2007/10/02)

Bridged-ring Nitrogen Compounds. Part 9. Use of a Ring-expansion Reaction for the Synthesis of 1,5-Methano-4-benzazonin-12-ones and Derivatives of Benzocycloheptapyrrole.
-
McKay, Roslyn,Proctor, George R.,Scopes, David I. C.,Sneddon, Andrew H.
p. 2024 - 2055
(2007/10/02)

NEW EVIDENCE FOR AND NEW REACTIONS OF ORTHO-LITHIO YLIDS
While α-lithio ylid 2 may be generated from triphenylphosphonio-bromomethylid through halogen/metal exchange, the reaction of triphenylphosphonio-methylid 1 with sec- or tert-butyllithium produces nearly quantitatively the o-lithio ylid 3, which is stable at -60 deg C but slowly decomposes at higher temperatures via a cyclization product 5 to give the α-lithio phosphine 4.
Schaub, Bruno,Schlosser, Manfred
p. 1623 - 1626
(2007/10/02)

The Stereocontrolled Horner-Wittig Reaction: Synthesis of Disubstituted Alkenes
Addition of the lithium derivatives of phosphine oxides Ph2P(O)CH2R1 to aldehydes gives erythro adducts (11) with good stereoselectivity.Reduction of α-diphenylphosphinoyl ketones (12) gives threo adducts (11) with even better stereoselectivity.Purification by flash chromatography and/or crystallisation followed by elimination of Ph2PO2 gives pure Z- or E-alkenes with high material conversion.Explanations are offered for the stereoselectivities, conditions defined for full stereochemical control, and guidelines suggested for approaches to a given alkene.
Buss, Antony D.,Warren, Stuart
p. 2307 - 2326
(2007/10/02)

REDUCTION OF PHOSPHONIUM SALTS WITH LITHIUM TETRAHYDROALUMINATE: CONVENIENT METHOD FOR THE PREPARATION OF ALKYLDIARYLPHOSPHINES
-
Makhaev, V. D.,Borisov, A. P.
p. 2279 - 2281
(2007/10/02)

Kinetics of Alkaline Hydrolysis of Quaternary Phosphonium Salts. The Influence of Aprotic Solvents on the Hydrolysis of Ethyl(phenyl)phosphonium Iodides.
Third-order rate constants have been determined for the hydrolyses of the ethyl(phenyl)phosphonium iodides (1) in aqueous methanol and in aqueous tetrahydrofuran.The very large increase in the rate of hydrolysis of tetra- and tri-arylphosphonium salts which is induced by the addition of tetrahydrofuran to the medium drops to almost zero for tetra- and tri-alkylphosphonium salts.This is attributed to an increase in the delocalisation of the positive charge in phosphorus, which leads to less specific solvation of the alkylphosphonium ions.
Dawber, J. Graham,Tebby, John C.,Waite, Albert A. C.
p. 1923 - 1926
(2007/10/02)

1H-NMR- AND MOESSBAUER INVESTIGATIONS ON THE ION PAIRS OF TETRACHLOROFERRATE(III) ANION WITH QUATERNARY PHOSPHONIUM CATIONS
Paramagnetic ion pairs were investigated by 1H-NMR and Moessbauer spectroscopy in chloroform and dimethyl sulphoxide.It has been shown that the chemical shifts of 1H-NMR peaks arise from a combination of contact and pseudocontact interactions of opposite sign, and the ratio of interactions was definitely influenced by the extent of solvation.On the basis of Moessbauer measurements it was shown that the change of the cation size had an effect on the electron delocalization and symmetry conditions of iron(III) in solid samples, too.In concentrated frozen solutions of ion pairs, different interactions were indicated by Moessbauer spectros copy in chloroform and dimethyl sulphoxide, in accordance with 1H-NMR results.However, in dilute solution such an anion-solvent interaction was observed directly, which could be shown by the NMR method only indirectly.
Vincze, L.,Papp, S.
p. 153 - 162
(2007/10/02)

REACTIONS IN TRIMETHYL PHOSPHITE - SODIUM ION - ORGANIC BASE TERNARY SYSTEMS
-
Nesterov, L. V.,Sabirova, R. A.
p. 31 - 34
(2007/10/02)

Process for preparation of terpene flavorants and novel intermediates therefor
A process for preparing compounds of the type of sinensal, which is suitable as a flavor-imparting agent of orange aroma, and novel intermediates including those having the general formula: SPC1 Wherein R signifies a CH2 OH, CHO or COOH group and the broken lines present a double bond emanating from C-atom 4, are disclosed.
-
(2008/06/13)