- A New Synthesis of Alkynyl Sulfones and Single Crystal X-ray Structure of p-(Tolylsulfonyl)ethyne
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The reaction of mono- or bis(alkynyliodonium) triflate salts with sodium p-toluenesulfinate under mild conditions affords alkynyl sulfones in 60-95percent yields.
- Tykwinski, Rik R.,Williamson, Bobby L.,Fischer, David R.,Stang, Peter J.,Arif, Atta M.
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- A simplified method for the preparation of ethynyl P-tolyl sulfone and ethynyl phenyl sulfone
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Silica gel mediated desilylation of aryl 2-(trimethylsilyl)ethynyl sulfones was found to greatly simplify the synthesis of the acetylenic sulfones, ethynyl p-tolyl sulfone 1 and ethynyl phenyl sulfone 2. Each were easily prepared in good yield and high purity on a multigram scale from bis(trimethylsilyl)acetylene 3.
- Chen,Trudell
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Read Online
- Large π-Conjugated Metal-Organic Frameworks for Infrared-Light-Driven CO2Reduction
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It remains challenging to excite traditional photocatalysts through near-infrared (NIR) light. Attempts to use NIR-light-response materials for photochemical reduction usually suffer from inapposite band position due to extremely narrow band gaps. Here, w
- Li, Qian-Ru,Wang, Xiao-Shuang,Xie, Bo-Ru,Zeng, Jin-Yue,Zhang, Xian-Zheng
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supporting information
p. 1218 - 1231
(2022/02/05)
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- Covalent Adaptable Networks with Tunable Exchange Rates Based on Reversible Thiol–yne Cross-Linking
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The design of covalent adaptable networks (CANs) relies on the ability to trigger the rearrangement of bonds within a polymer network. Simple activated alkynes are now used as versatile reversible cross-linkers for thiols. The click-like thiol–yne cross-linking reaction readily enables network synthesis from polythiols through a double Michael addition with a reversible and tunable second addition step. The resulting thioacetal cross-linking moieties are robust but dynamic linkages. A series of different activated alkynes have been synthesized and systematically probed for their ability to produce dynamic thioacetal linkages, both in kinetic studies of small molecule models, as well as in stress relaxation and creep measurements on thiol–yne-based CANs. The results are further rationalized by DFT calculations, showing that the bond exchange rates can be significantly influenced by the choice of the activated alkyne cross-linker.
- Du Prez, Filip E.,Guerre, Marc,Maes, Diederick,Unal, Kamil,Van Herck, Niels,Winne, Johan M.
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supporting information
p. 3609 - 3617
(2020/02/04)
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- Metal-free synthesis of activated ynesulfonamides and tertiary enesulfonamides
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An operationally simple synthesis of activated ynesulfonamides and enesulfonamides is described. Ynesulfonamides can be obtained through reaction of sulfonylamides with activated bromoalkynes and Triton B in a short time at room temperature. Likewise, terminal alkynes react with sulfonylamides to provide enesulfonamides. Z/E enesulfonamides can be transformed exclusively into E enesulfonamides.
- Andna, Lucile,Miesch, Laurence
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supporting information
p. 5688 - 5692
(2019/06/19)
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- Synthesis, Structural and Optical Properties of Tetrabenzoporphyrin Complexes Bearing Four or Eight Peripheral Phenyl Groups
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A series of free-base and phosphorus(V) complexes of tetrabenzoporphyrin (TBP) and some phosphorus(V) porphyrins containing four or eight phenyl groups on the periphery have been synthesized and characterized by X-ray crystallography, electronic absorption, and magnetic circular dichroism (MCD) spectroscopy, together with quantum chemical calculations. All phosphorus TBP and meso-tetraphenyl porphyrin complexes adapted ruffled conformations due to the small P(V) ion, although the Zn(II)TBPs containing eight phenyl (Φ) groups at the so-called β and α positions showed planar and saddled structures in the solid state, due to, respectively, marginal or severe steric hindrance between the neighboring Φ groups. All P(V)TBPs showed the Soret and Q bands beyond 450 and 700 nm, respectively, which are some of the longest wavelengths exhibited by metallated TBPs reported to date. Of the eight Φ group-substituted P(V)TBPs, those substituted at α positions always showed absorption bands at longer wavelengths than those at β positions, which was reproduced by calculated absorption spectra. The Soret band positions of meso-tetraphenylated P(V) species without fused benzo-groups (ca. 430–440 nm) were also some of the longest among metalloporphyrins of this type.
- Furuyama, Taniyuki,Okujima, Tetsuo,Muramatsu, Kota,Takahashi, Yuichi,Mikami, Akihiro,Fukumura, Tomoteru,Mori, Shigeki,Nakae, Takahiro,Takase, Masayoshi,Uno, Hidemitsu,Kobayashi, Nagao
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supporting information
p. 3224 - 3235
(2019/05/29)
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- Gold-Catalyzed Dehydrazinative C(sp)–S Coupling Reactions of Arylsulfonyl Hydrazides with Ethynylbenziodoxolones for Accessing Alkynyl Sulfones
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A gold(III)-catalyzed dehydrazinative coupling reaction between arylsulfonyl hydrazides and ethynylbenziodoxolone reagents was realized for the synthesis of alkynyl sulfones. The scope and versatility of the reaction were demonstrated by the efficient synthesis of 23 derivatives with diverse structural features.
- Shinde, Popat S.,Patil, Nitin T.
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p. 3512 - 3515
(2017/07/04)
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- Synthesis of Azacyclic Nucleoside Analogues via Asymmetric [3 + 2] Cycloaddition of 9-(2-Tosylvinyl)-9H -purines
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With 9-(2-tosylvinyl)-9H-purines as the dipolarophiles, a series of chiral azacyclic nucleosides with four continuous stereocenters were obtained in 86-99% yields, >20:1 dr, and 94 → 99% ee via the Cu(I)-catalyzed asymmetric [3 + 2] cycloaddition. Both (E)- and (Z)-9-(2-tosylvinyl)-9H-purines were suitable dipolarophiles, enriching the structure diversity of azacyclic nucleosides. Furthermore, when α-methyl imino ester was explored, the corresponding azacyclic nucleoside with a chiral quaternary stereocenter could also be afforded with excellent results. (Chemical Equation Presented).
- Zhang, Dan-Jie,Xie, Ming-Sheng,Qu, Gui-Rong,Gao, Yao-Wei,Guo, Hai-Ming
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supporting information
p. 820 - 823
(2016/03/01)
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- A facile and reliable method for the synthesis of tetrabenzoporphyrin from 4,7-dihydroisoindole
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A new route to tetrabenzoporphyrins from the closest possible precursor of the unstable isoindole was developed. A key feature of this route is a dramatic facilitation of the aromatization of annelated rings, which is the most serious bottleneck in previo
- Filatov, Mikhail A.,Cheprakov, Andrei V.,Beletskaya, Irina P.
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p. 3468 - 3475
(2008/02/12)
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- Synthesis of a fluorine-18 labeled derivative of epibatidine for in vivo nicotinic acetylcholine receptor PET imaging
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Epibatidine (exo-2-(2'-chloro-5'-pyridyl)-7-azabicyclo[2.2.1]heptane), a natural compound isolated from the skin of the Ecuadorian poison frog Epipedobates tricolor, is the most potent nicotinic acetylcholine receptor (nAChR) agonist reported to date. In order to visualize and quantify in vivo these receptors in human brain using Positron Emission Tomography (PET), [18F]norchlorofluoroepibatidine (exo-2-(2'-[18F]fluoro-5'-pyridyl)-7-azabicyclo[2.2.1]heptane), a fluorine-18 (t(1/2): 110min) radiolabeled derivative of epibatidine has been designed. The corresponding 2'-bromo-, 2'-iodo- and 2'-nitro exo-2-(5'-pyridyl)-7-azabicyclo[2.2.1]heptane analogues as labeling precursors, as well as norchlorofluoroepibatidine as a reference compound have been synthesized by reductive, stereoselective, palladium-catalyzed Heck-type coupling between an N-Boc protected azanorbornene and the corresponding halopyridine. [18F]Norchlorofluoroepibatidine has been radiolabeled with fluorine-18 by nucleophilic aromatic substitution from the corresponding Boc-protected halo- and nitro precursors using [18F]FK-K222 complex in DMSO by conventional heating (at 150-180°C for 10min) or microwave activations (at 100 Watt, for 1 to 2.5min), followed by TFA-removal of the protective group. Typically, using the microwave activation procedure, 60-80mCi (2.22-2.96 GBq) of pure [18F]norchlorofluoroepibatidine could be obtained in less than 2h (110-115min) from the bromo labeling precursor, with specific radioactivities of 1.5-2.5Ci/μmol (55.5-92.5GBq/μmol) calculated for End of Bombardment. The preliminary PET experiments in baboon (Papio papio) with [18F]norchlorofluoroepibatidine show a high uptake and a rapid accumulation of the radiotracer into the brain within 30min. In the thalamus, a nAChR rich area, uptake of radioactivity reached a maximum at 40min (10% I.D./100mL tissue). The ratio of radioactivity thalamus/cerebellum (the latter being a nAChR poor area) was 2 at 40min and increased with time, up to 4.3 at 160min. Its specific regiodistribution and its high ratio of specific-to-nonspecific binding confirm the ideal profile of [18F]norchlorofluoroepibatidine as a suitable radioligand for PET imaging of nAChRs in the brain. Copyright (C) 1999 Elsevier Science Ltd.
- Dolci, Lilian,Dolle, Frederic,Valette, Heric,Vaufrey, Francoise,Fuseau, Chantal,Bottlaender, Michel,Crouzel, Christian
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p. 467 - 479
(2007/10/03)
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- 2-(Het)aryl-substituted 7-azabicyclo[2.2.1]heptane systems
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Epibatidine (1) is a recently discovered trace alkaloid found in the skin of a Latin-Amencan poisonous frog. Its remarkably high analgetic activity is accompanied by high toxicity. Therefore, in order to tune its biological activity, a convergent and effi
- Otten, Albert,Namyslo, Jan Christoph,Stoermer, Martin,Kaufmann, Dieter E.
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p. 1997 - 2001
(2007/10/03)
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- Reactions of (E)-2-Iodo-1-tosyl-1-alkenes as Useful Synthetic Intermediates
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(E)-2-Iodo-1-tosyl-1-alkenes readily available by iodosulfonization of 1-alkynes were found to be useful synthons for the regio- and/or stereoselective preparation of 1-tosyl-1-alkynes, 1-tosyl-2-alkynes, (Z)-vinyl and (Z)-allyl sulfones, β-tosyl enamines
- Iwata, Noriyoshi,Morioka, Tetsuro,Kobayashi, Toshifumi,Asada, Takahiro,Kinoshita, Hideki,Inomata, Katsuhiko
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p. 1379 - 1388
(2007/10/02)
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- Sulfonylation of Organometallic Reagents with Arenesulfonyl Fluorides: A Simple One-Step Synthesis of Sulfones
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Sulfonylation of organometallic reagents was accomplished with arenesulfonyl fluorides to provide a wide variety of alkylaryl- and diaryl sulfones.Organolithium and diorganocopper lithium reagents react smoothly with arenesulfonyl fluorides to give sulfones in high yields.Alkyl Grignard reagents often lead to mixtures of monosulfonylated and disulfonylated products.However, allylmagnesium chloride and phenylmagnesium chloride provide the corresponding sulfones in excellent yields.Organocopper reagents were also found to yield sulfones upon treatment with arenesulfonyl fluorides.By utilizing this methodology, synthetically useful alkyl, (trimethylsilyl)methyl, and allyl sulfones are easily prepared in high yields.
- Frye, Leah L.,Sullivan, Eileen L.,Cusack, Kevin P.,Funaro, John M.
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p. 697 - 701
(2007/10/02)
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- Aromatic stabilization of the triarylborirene ring system by tricoordinate boron and facile ring opening with tetracoordinate boron
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To remove uncertainties in the apparent C=C and B-C bond lengths of the borirene ring, as previously estimated from an X-ray crystallographic analysis of trimesitylborirene, the unsymmetrically substituted 2-(2,6-dimethylphenyl)-1,3-dimesitylborirene was
- Eisch, John J.,Shafii, Babak,Odom, Jerome D.,Rheingold, Arnold L.
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p. 1847 - 1853
(2007/10/02)
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- Alkynes from 5-Aminoisoxazoles
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Diazotization of 5-aminoisoxazoles that bear at least one electron-withdrawing group by reaction with sodium nitrite in AcOH-H2O affords substituted acetylenes.A reaction path is proposed.
- Beccalli, Egle M.,Manfredi, Amedea,Marchesini, Alessandro
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p. 2372 - 2375
(2007/10/02)
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- Selenosulfonation of Acetylenes: Preparation of Novel β-(Phenylseleno)vinyl Sulfones and Their Conversion to Acetylenic and β-Functionalized Sulfones
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The 1,2-additions of Se-phenyl p-tolueneselenosulfonate (1) to acetylenes under mild conditions afford β-(phenylseleno)vinyl sulfones 3, generally in high yields.The reaction is highly regioselective (anti-Markovnikov) and stereoselective (anti) and proceeds via a free-radical chain mechanism initiated by the thermolysis of the selenosulfonate.The oxidation of β-(phenylseleno)vinyl sulfones with m-chloroperbenzoic acid generates the corresponding selenoxides 4, which undergo syn or base-catalyzed elimination to furnish acetylenic sulfones 5.Base-catalyzed alcoholyses of selenoxides 4 in methanol or ethylene glycol produce β-keto sulfone ketals 8 or 10, respectively.Free β-keto sulfones 11 are formed by the acid-catalyzed hydrolysis of the corresponding β-(phenylseleno)vinyl sulfones 3.
- Back, Thomas G.,Collins, Scott,Kerr, Russell G.
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p. 3077 - 3084
(2007/10/02)
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- Lewis Acid Catalyzed Ene Reactions of Ethynyl p-Tolyl Sulfone
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Ethynyl p-tolyl sulfone undergoes EtAlCl2-catalyzed ene reactions with alkenes to give 1,4-dienyl p-tolyl sulfones in good yield.
- Snider, Barry B.,Kirk, Thomas C.,Roush, David M.,Gonzalez, Domingo
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p. 5015 - 5017
(2007/10/02)
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