- Addition of water to arylidenecyclopropanes: A highly efficient method for the preparation of gem-aryl disubstituted homoallylic alcohols
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Arylidenecyclopropanes react with water in the presence of a catalytic amount of Cu(OTf)2 to afford the corresponding gem-aryl disubstituted homoallylic alcohols in good to excellent yields.
- Siriwardana, Amal I.,Nakamura, Itaru,Yamamoto, Yoshinori
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Read Online
- Ring opening of methylenecyclopropanes with halides in liquid sulfur dioxide
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Methylenecyclopropanes (MCP) undergo ring opening reactions with group I and II metal halides and ammonium halides in liquid SO2 to afford homoallylic halides, which are versatile reagents in organic synthesis. The developed reaction conditions are compatible with acid-labile substrates such as N-Boc-protected compounds. Liquid SO2 is a polar reaction medium with Lewis acid properties that solubilizes inorganic salts. The unique properties of SO2 were demonstrated by control experiments: 1) upon performing the reactions with the aforementioned salts in conventional solvents, the MCP ring opening was not observed either in the presence of catalytic amounts of H3PO4 (similar pKa to that of H2SO3), or in the absence of H3PO4; 2) a solution of SO2 in THF exhibited similar properties to that of liquid SO2.
- Le?kovskis, Kristaps,Gulbe, Krista,Mishnev, Anatoly,Turks, Māris
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supporting information
(2020/10/19)
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- Strain-Promoted Oxidation of Methylenecyclopropane Derivatives using N-Hydroxyphthalimide and Molecular Oxygen in the Dark
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The hydroperoxidation of alkylidenecyclopropanes and other strained alkenes using an N-hydroxylamine and molecular oxygen occurred in the absence of catalyst, initiator, or light. The oxidation reaction proceeds through a radical pathway that is initiated by autoxidation of the alkene substrate. The hydroperoxides were converted to their corresponding alcohols and ketones under mild conditions.
- Anderson, T. E.,Woerpel, K. A.
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supporting information
(2020/07/30)
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- MONO HALOGEN OR METHYL-SUBSTITUTED 5-HT2B ANTAGONISTS WITH INCREASED ACTIVITY
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Disclose herein are mono halogen or methyl-substituted 5-HT 2B antagonist compounds, which have been found with increased binding activity to 5-HT 2B receptor due to the substitution of halogen or methyl, and the method of using the compounds of treating or preventing a disorder mediated by 5-HT 2B.
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Paragraph 0092
(2020/05/13)
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- Method for simply preparing high-purity olopatadine hydrochloride intermediate (by machine translation)
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The invention provides a simple and convenient method for preparing high-purity [3 - (dimethylamine) propyl] triphenylphosphonium bromide hydrobromide. The obtained (1,3 - bromopropyl) triphenylphosphonium bromide does not need to be separated, and is directly reacted with a dimethylamine aqueous solution in n-heptane so as to obtain [3 - 3 - (dimethylamine) propyl] triphenyl phosphonium bromide hydrobromide crude product which is obtained by hot pulping with anhydrous ethanol to obtain the high-purity [3 - 3 - (dimethylamine) propyl] triphenylphosphonium bromide hydrobromide. (by machine translation)
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Paragraph 0027-0047; 0073-0075
(2020/08/26)
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- [C^N]-Alkenyl Gold(III) Complexes by Proximal Ring-Opening of (2-Pyridyl)alkylidenecyclopropanes: Mechanistic Insights
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Pyridine-substituted alkylidenecyclopropanes (Py-ACPs) react with gold(III) salts under mild reaction conditions through an unprecedented, proximal ring-opening pathway, to generate highly appealing, catalytically active pyridine alkenyl [C^N]-gold(III) species. Mechanistic studies reveal that the activation of the C?C bond of the ACP takes place through an unusual concerted, σ-bond metathesis type-process.
- González, Jorge A.,López, Fernando,Mascare?as, José Luis,Nevado, Cristina,Verdugo, Felipe
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supporting information
p. 20049 - 20054
(2020/09/09)
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- Two Are Better Than One: A Design Principle for Ultralong-Persistent Luminescence of Pure Organics
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Because of their innate ability to store and then release energy, long-persistent luminescence (LPL) materials have garnered strong research interest in a wide range of multidisciplinary fields, such as biomedical sciences, theranostics, and photonic devices. Although many inorganic LPL systems with afterglow durations of up to hours and days have been reported, organic systems have had difficulties reaching similar timescales. In this work, a design principle based on the successes of inorganic systems to produce an organic LPL (OLPL) system through the use of a strong organic electron trap is proposed. The resulting system generates detectable afterglow for up to 7 h, significantly longer than any other reported OLPL system. The design strategy demonstrates an easy methodology to develop organic long-persistent phosphors, opening the door to new OLPL materials.
- Alam, Parvej,Leung, Nelson L. C.,Liu, Junkai,Cheung, Tsz Shing,Zhang, Xuepeng,He, Zikai,Kwok, Ryan T. K.,Lam, Jacky W. Y.,Sung, Herman H. Y.,Williams, Ian D.,Chan, Christopher C. S.,Wong, Kam Sing,Peng, Qian,Tang, Ben Zhong
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- Evaluation of synthetic substituted 1,2-dioxanes as novel agents against human leishmaniasis
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The treatment of human leishmaniasis is currently based on few compounds that are highly toxic, expensive and have a high rate of treatment failure. A number of recent studies on new drugs focuses on natural or semi-synthetic compounds. Among them, the endoperoxide artemisinin, extracted from Artemisia annua, and some of its derivatives have shown leishmanicidal activity. In the present work, a series of structurally simple, fully synthetic 1,2-dioxanes were evaluated for in vitro antileishmanial activity against promastigotes of Leishmania donovani; the cytotoxicity for mammalian cells was also assessed. The six most promising compounds in terms of activity and selectivity were further investigated for their antileishmanial activity on the promastigote forms of L. tropica, L. major and L. infantum and against L. donovani amastigotes. The good performance in terms of potency and selectivity makes these six hits promising candidates for a preliminary lead optimization as antileishmanial agents.
- Ortalli,Varani,Rosso,Quintavalla,Lombardo,Trombini
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supporting information
p. 126 - 140
(2019/03/19)
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- Crystal structure, characterization, Hirshfeld surface analysis and DFT studies of two [propane 3-bromo-1-(triphenyl phosphonium)] cations containing bromide (I) and tribromide (II) anions: The anion (II) as a new brominating agent for unsaturated compounds
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In this study, propane 3-bromo-1- (triphenyl phosphonium) bromide, I, and propane 3-bromo-1- (triphenyl phosphonium) tribromide, II, (II as a new brominating agent) were synthesized and characterized by 1H NMR, 13C NMR, 31P NMR, FT-IR, spectroscopy, Thermogravimetric Analysis, Differential thermal analysis, Differential scanning calorimetry and single crystal X-ray analysis. Density functional theory calculations (energy, structural optimization and frequencies, Natural Bond Orbital, absorption energy and binding energy) were performed by using B3LYP/6-311 G++ (d, p) level of theory. Hirshfeld surface analysis and fingerprint plots were utilized to investigate the role of bromide and tribromide anions on the crystal packing structures of title compounds. The results revealed that the change of accompanying anionic moiety can affect the directional interactions of C-H?Br hydrogen bonds between anionic and cationic units in which the H?Br with a proportion of 53.8% and 40.9% have the major contribution in the stabilization of crystal structures of I and II, respectively. Furthermore, the thermal stability of new brominating agent II with tribromide anion was compared with compound I with bromide anion. Nontoxicity, short reaction time, thermal stability, simple working up and high yield are some of the advantages of these salts.
- Nokhbeh, Seyed Reza,Gholizadeh, Mostafa,Salimi, Alireza,Sparkes, Hazel A.
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p. 542 - 554
(2019/06/18)
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- Improved Electrocatalytic CO2 Reduction with Palladium bis(NHC) Pincer Complexes Bearing Cationic Side Chains
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Stabilizing interactions between charged electrocatalytic intermediates and a series of cationic residues were explored through the synthesis and characterization of six palladium bis(N-heterocyclic carbene) (NHC) complexes bearing unique onium functionalities. The presence of a positively charged, pendant substituent was found to mediate electrode kinetics and facilitate CO2 coordination to the catalytic center in a systematic fashion. The introduction of cationic moieties into this system is shown to enhance catalytic selectivity for the conversion of CO2 to CO by as much as 5 times that of an alkyl-bearing analog. A combination of electrochemical experiments and computational analysis demonstrates that catalyst performance benefits most from a bulky onium unit tethered to the catalyst through a flexible linker. This behavior was interpreted as a preference for a wide, hydrophobic reaction pocket that allows for the unhindered formation of catalytic intermediates and mediated interaction with the solution.
- Deluca, Emile E.,Xu, Zhen,Lam, Jasper,Wolf, Michael O.
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supporting information
p. 1330 - 1343
(2019/03/28)
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- Mitochondria-targeted dihydropyridine derivative as well as preparation method and application thereof
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The invention discloses a preparation method and application of a mitochondria-targeted dihydropyridine compound. The mitochondria-targeted dihydropyridine compound has structures of a formula (I) and a formula (II) (shown in the description). Experiments prove that the mitochondria-targeted dihydropyridine compound is capable of effectively eliminating reactive oxygen species (ROS) generated by ionization radiation and therefore can be applied to the treatment of free radical-induced relevant diseases such as Alzheimer's disease and ionization damage disease. The preparation method is simple, and the product is easily prepared and pollution-free.
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Paragraph 0062
(2017/10/13)
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- Synthesis of Fluorinated Homoallylic Compounds by Fluoroalkyl Radical Mediated Ring Opening of Methylenecyclopropanes
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The fluoroalkyl (Rf) radical mediated ring opening of methylenecyclopropanes (MCPs) 1 and subsequent atom transfer were investigated. In the first part, a copper-initiated radical reaction of Rf-X (X = I, Br) with MCP 1 gave homoallylic halides 2 in excellent yields. Similarly, radical reaction of the RfTMS/CsF/PhI(OCOR)2 system with MCP 1 led to homoallylic alcohol esters 3 in moderate to good yields. An efficient synthesis of fluoroalkyl (Rf)-substituted homoallylic halides 2 and homoallylic alcohol esters 3 by fluoroalkyl radical mediated ring opening of methylenecyclopropanes (MCPs) 1 followed by an atom-transfer process is developed.
- Xie, Huajun,Xu, Bo
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supporting information
p. 2594 - 2598
(2016/06/08)
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- Synthesis of 2,3-Disubstituted Quinolines via Ketenimine or Carbodiimide Intermediates
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Cyclopenta[b]quinolines and cyclohexa[b]quinolines were prepared via the reactions of α-diazo ketones with N-(2-cyclopropylidenemethylphenyl)phosphanimines and N-(2-cyclobutylidenemethylphenyl) phosphanimine, respectively. The reaction proceeds in a cascade involving ketenimine formation, 6 π-electron ring closure, and 1,3-alkyl shift. A similar approach was developed for the synthesis of dihydropyrrolo-[2,3-b]quinolines from N-(2-cyclopropylidenemethylphenyl)phosphanimines and isocyanates.
- Zhao, Hongyang,Xing, Yanpeng,Lu, Ping,Wang, Yanguang
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supporting information
p. 15144 - 15150
(2016/10/11)
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- A bromine-radical mediated three-component reaction comprising allenes, electron-deficient alkenes and allyl bromides: Facile synthesis of 2-bromo-1,7-dienes
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A bromine-radical mediated three-component coupling reaction was effectively achieved by the use of allenes, electron-deficient alkenes, and allyl bromides and led to the synthesis of 2-bromo-1,7-dienes in good to high yields. This protocol was extended to the three-component process using alkylidenecyclopropane, which gave 2-bromo-1,8-diene along with alkylidenecyclopentane. the Partner Organisations 2014.
- Kippo, Takashi,Ryu, Ilhyong
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supporting information
p. 5993 - 5996
(2014/05/20)
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- Silver(I)-mediated dual cleavage of C-C and C-O bonds in the reaction of diarylmethylenecyclopropanes with tetrahydrofuran: Synthesis of 4-(3-halobut-3-enyloxy)butyl 2,2,2-trifluoroacetate derivatives
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The reaction of methylenecyclopropanes (MCPs) with tetrahydrofuran (THF) proceed smoothly in the presence of AgOC(O)CF3 and electrophilic halogenation reagents to give the corresponding 4-(3-halobut-3-enyloxy)butyl 2,2,2-trifluoroacetate derivatives in moderate yields through dual cleavage of C-C and C-O bonds under mild conditions. Novel 4-(3-halobut-3-enyloxy)butyl 2,2,2-trifluoroacetate derivatives can be synthesized by AgI-mediated reactions of arylmethylenecyclopropanes with tetrahydrofuran at room temperature through dual cleavage of C-C and C-O bonds. Copyright
- Chen, Gen-Qiang,Tang, Xiang-Ying,Shi, Min
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supporting information
p. 194 - 197
(2014/01/06)
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- ω-Thioacetylalkylphosphonium salts: Precursors for the preparation of phosphonium-functionalised gold nanoparticles
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Two new ω-thioacetylalkylphosphonium salts that function as masked cationic alkanethiolate ligands for the stabilisation of gold nanoparticles have been prepared. Both (3-thioacetylpropyl)triphenylphosphonium bromide and (6-thioacetylhexyl)triphenylphosphonium bromide were shown to form water-soluble gold nanoparticles of ca. 5-10 nm in size that are stable for up to six months. The related (3-thioacetylpropyl)diphenylphosphine oxide was also prepared but did not act as a stabilising ligand in gold nanoparticle formation.
- Ju-Nam, Yon,Allen, David W,Gardiner, Philip H.E.,Bricklebank, Neil
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body text
p. 3504 - 3508
(2009/02/05)
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- Polymorphic forms of olopatadine hydrochloride and methods for producing olopatadine and salts thereof
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The present invention provides a novel polymorphic form of olopatadine hydrochloride ([(Z)-3-(dimethylamino)propylidene]-6,11-dihydrodibenz[b,e]oxepin-2-acetic acid hydrochloride), a selective histamine H1-receptor antagonist that is used for the treatment of ocular symptoms of seasonal allergic conjunctivitis. The present invention also provides novel methods for producing olopatadine on a large scale, and in a manner that is cost effective, provides a low level of impurities and eliminates the need to use the costly and dangerous base, butyllithium, which is used in prior art reactions for making olopatadine. The present invention further provides novel processes for carrying out a large scale production of 3-dimethylaminopropyltriphenylphosphonium bromide and its corresponding hydrobromide salt, which are employed in the production of olopatadine, and pharmaceutically acceptable salts of olopatadine.
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Page/Page column 24
(2008/06/13)
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- Phosphonioalkylthiosulfate zwitterions - New masked thiol ligands for the formation of cationic functionalised gold nanoparticles
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We report the synthesis and structural characterisation of a new family of stable phosphonioalkylthiosulfate zwitterions, R3P +(CH2)nS2O3- (R = Ph or Bu, n = 3,4,6, 8 or 10) which behave as cationic masked thiolate ligands with applications in the functionalisation of gold nanoparticles, having potential as new diagnostic biorecognition systems. The ligands were prepared by treatment of ω-bromoalkylphosphonium salts with sodium thiosulfate. The crystal and molecular structures of the zwitterions (R = Ph, n = 3) and (R = Bu, n = 3) were determined. A series of phosphonioalkanethiolate-capped gold nanoparticles dispersed in water was prepared by borohydride reduction of potassium tetrachloroaurate in the presence of the zwitterions in a dichloromethane-water system. UV-visible spectroscopy and scanning transmission electron-microscopy indicated that capped nanoparticles of ca. 5 nm diameter were present. The Royal Society of Chemistry 2006.
- Yon, Ju-Nam,Bricklebank, Neil,Allen, David W.,Gardiner, Philip H. E.,Light, Mark E.,Hursthouse, Michael B.
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p. 4345 - 4351
(2008/09/19)
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- Enantioselective synthesis of γ-aryl-γ-butyrolactones by sequential asymmetric epoxidation, ring expansion, and Baeyer-Villiger oxidation
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(Chemical Equation Presented) This paper describes an enantioselective synthesis of γ-butyrolactones, using the N-tolyl-substituted oxazolidinone-containing ketone as catalyst and Oxone as oxidant via a sequential asymmetric epoxidation of benzylidenecyclopropanes, ring expansion, and Baeyer-Villiger oxidation. Up to 91% ee was obtained. Optically active cyclobutanones can also be obtained by suppressing the Baeyer-Villiger oxidation with use of more ketone catalyst and less Oxone.
- Wang, Bin,Shen, Yu-Mei,Shi, Yian
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p. 9519 - 9521
(2007/10/03)
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- Therapeutic agents
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Compounds of formula I STR1 and pharmaceutically acceptable salts thereof in which R1, R2 and R3 independently represent hydrogen, hydroxy, halo, alkyl or alkoxy; ALK1 represents a C2-6 alkylene chain optionally substituted by one or more C1-2 alkyl groups; Y represents a piperidine ring which is attached through nitrogen to ALK1 ; R4 represents hydrogen or a C1-4 alkyl group; the broken line in --- represents a bond, or is absent and the free valency on Y is taken up by hydrogen and the free valency on CR4 is taken up by hydrogen or a C1-4 alkyl group; ALK2 is absent or represents a C1-4 alkylene chain optionally substituted by one or more C1-2 alkyl groups; and R5 and R6 independently represent hydrogen, alkyl, phenyl, alkyl (optionally substituted) or R5 and R6 together with the nitrogen atom to which they are attached represent a saturated 3-7 membered heterocyclic ring (with a proviso); are disclosed which are antiinflammatory, antiallergic and immunomodulatory agents. Compositions containing these compounds and processes to prepare these compounds are also disclosed.
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- Stereospecific synthesis of Z olefins bearing an ω-azido group.
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Ylides derived from ω-azidoalkyltriphenylphosphonium salts were generated at low temperature.They are stable at -80 deg C for several hours and react smoothly and stereospecifically with typical aldehydes to form Z-ω-azido olefins which are the precursors of ω-unsaturated primary and secondary amines.
- Chhen, A.,Vaultier, M.,Carrie, R.
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p. 4953 - 4956
(2007/10/02)
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- HIGHLY REACTIVE EQUIVALENTS OF ALLYLIDENETRIPHENYLPHOSPHORANES FOR THE STEREOSPECIFIC SYNTHESIS OF 1,3-DIENES BY CIS-OLEFINATION OF HINDERED ALDEHYDES
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Ylides derived from 3-dimethylaminopropyltriphenylphosphonium salts react smoothly and stereospecifically with even hindered aldehydes to form Z-olefins which are easily converted to 1,3-dienes.
- Corey, E. J.,Desai, Manoj C.
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p. 5747 - 5748
(2007/10/02)
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- Notes Unsymmetrical Bis(phosphorus) Compounds: Synthesis of Unsymmetrical Ditertiary Phosphines, Phosphine Oxides, and Diquaternary Phosphonium Salts
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A convenient preparative route to the unsymmetrical bidentate phosphines R2P(CH2)nPPh2 (R=Me or Et; n=3 or 4) is described.This involves the synthesis of unsymmetrical diphosphonium salts, Br2, and diphosphine oxides, R2P(O)(CH2)nPPh2, as intermediates.The symmetrical ligand Et2P(CH2)3PEt2 was also prepared by the same route.New co-ordination complexes of manganese(II) with these ligands have been isolated.
- Benn, Roger F.,Briggs, Josie C.,McAuliffe, Charles A.
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p. 293 - 296
(2007/10/02)
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The ω-acyloxy n-propylidenephosphoranes give 2,3-dihydrofurans in toluene, and cyclopropylcetones in t-butanol. The mechanism of these reactions was investigated; formation of cyclopropylketone does not result from intramolecular condensation but from two
- Hercouet,le Corre
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p. 2855 - 2860
(2007/10/02)
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