- Ru-catalysed C(sp2)-H vinylation/annulation of benzoic acids and alkynes: rapid access to medium-sized lactones
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An unprecedented ruthenium catalysed [4+4] annulation of readily available benzoic acids and alkynes is reported for the first time. The carboxylate group acts as both a directing group and an internal nucleophilic reagent to facilitate a C(sp2
- Hu, Xiao-Qiang,Liu, Zi-Kui,Hou, Ye-Xing,Zhang, Guodong,Gao, Yang
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Read Online
- (: Z)-Tetrahydrothiophene and (Z)-tetrahydrothiopyran synthesis through nucleophilic substitution and intramolecular cycloaddition of alkynyl halides and EtOCS2K
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This protocol provides a novel, environmentally friendly and simple method for the synthesis of (Z)-tetrahydrothiophene derivatives using the nucleophilic thiyl radical intramolecular cycloaddition cascade process to construct C-S bonds under transition-m
- Luo, Xianglin,Li, Yibiao,Chen, Xiuwen,Song, Zhiyan,Liang, Junyi,Liao, Chunshu,Zhu, Zhongzhi,Chen, Lu
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Read Online
- Interrupted Carbonyl-Alkyne Metathesis
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Carbonyl-olefin metathesis and carbonyl-alkyne metathesis represent established reactivity modes between carbonyls, alkenes, and alkynes under Lewis and Br?nsted acid catalysis. Recently, an interrupted carbonyl-olefin metathesis reaction has been reporte
- McFarlin, Austin T.,Watson, Rebecca B.,Zehnder, Troy E.,Schindler, Corinna S.
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- An imidazole-functionalized polyacetylene: Convenient synthesis and selective chemosensor for metal ions and cyanide
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A new light-emitting polyacetylene bearing imidazole moieties in the side chain (P1), was conveniently prepared through a postfunctionalization strategy, as a sensory polymer to selectively report the presence of Cu2+ (with a detection limit of
- Zeng, Qi,Cai, Ping,Li, Zhen,Qin, Jingui,Tang, Ben Zhong
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Read Online
- Organocobaloxime in organic synthesis: efficient trapping of 5-phenylpent-4-ynyl radical by useful functional groups
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5-Phenylpent-4-ynyl cobaloxime, R(CoIII) reacts with the free radical precursors XY under thermal or photochemical conditions to give the corresponding organic product RX or RY, depending on the precursor.A non-chain radical mechanism is invoked to account for the product distribution. Key words: Cobaloxime; Radical
- Das, Indira,Roy, Sujit
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Read Online
- Decarbonylative Sonogashira Cross-Coupling of Carboxylic Acids
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Decarbonylative Sonogashira cross-coupling of carboxylic acids by palladium catalysis is presented. The carboxylic acid is activated in situ by the formation of a mixed anhydride and further decarbonylates using the Pd(OAc)2/Xantphos system to provide an aryl-Pd intermediate, which is intercepted by alkynes to access the traditional Pd(0)/(II) cycle using carboxylic acids as ubiquitous and orthogonal electrophilic cross-coupling partners. The methodology efficiently constructs new C(sp2)-C(sp) bonds and can be applied to the derivatization of pharmaceuticals. Mechanistic studies give support to decarbonylation preceding transmetalation in this process.
- Liu, Chengwei,Szostak, Michal
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supporting information
p. 4726 - 4730
(2021/06/28)
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- SYNTHESIS OF CAPSAICIN DERIVATIVES
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The present invention relates to the synthesis of capsaicin derivatives, specifically to the synthesis of 6-heptyne derivatives of capsaicin.
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Page/Page column 32-33
(2021/09/26)
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- Sonogashira Cross-Coupling of Aryltrimethylammonium Salts
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A protocol for C(sp)-C(sp2) bond formation via the Sonogashira coupling reaction involving C-N bond cleavage with aryltrimethylammonium triflate as an electrophilic coupling partner is described in this work. The reactions proceeded well under mild conditions with a stoichiometric ratio of alkyl, aryl, or heteroaryl acetylenes and provided yields of up to 93%. Numerous useful functional groups were tolerated under the reaction conditions. Direct amine alkynylation can be achieved through a one-pot process without the isolation of ammonium salt. The protocol can be performed on a gram scale. Density functional theory calculations were performed to investigate the reaction mechanism that involved oxidative addition, alkyne coordination, deprotonation, and reductive elimination, which yielded the cross-coupling product.
- Chen, Qianwei,Gao, Fengchen,Tang, Huiling,Yao, Miao,Zhao, Qian,Shi, Yanhui,Dang, Yanfeng,Cao, Changsheng
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p. 3730 - 3736
(2019/04/13)
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- A Commercially Available and User-Friendly Catalyst for Hydroamination Reactions under Technical Conditions
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The activity of a simple, commercially available copper salt, [Cu(NCMe)4](BF4) in intramolecular hydroamination reactions of alkynes and allenes is presented. Reactions were successfully carried out in technical acetonitrile in the presence of air. While attempts of alkene hydroamination failed, this catalyst was also found active in intermolecular aza-Michael reactions.
- Zelenay, Benjamin,Munton, Peter,Tian, Xiaojie,Díez-González, Silvia
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p. 4725 - 4730
(2019/08/01)
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- Palladium(II) complex for catalyzing sonogashira coupling reactions and a method thereof
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A palladium(II) complex which catalyzes the Sonogashira coupling reaction efficiently under aerobic condition and a method of employing the palladium(II) complex to synthesize internal alkynes. The palladium(II) complex is an effective catalyst for the co
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Page/Page column 19
(2017/02/09)
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- SOLID-SUPPORTED PALLADIUM (II) COMPLEX AS A HETEROGENEOUS CATALYST FOR CROSS COUPLING REACTIONS AND METHODS THEREOF
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A solid-supported catalyst ligand which chelates palladium (II) species to form a complex that functions as a heterogeneous catalyst that is stable and can be recycled without significantly losing any catalytic activity in a variety of chemical transformations, a method for producing the solid-supported catalyst ligand and a method for catalyzing a palladium cross-coupling reaction, such as the Suzuki-Miyaura, Mizoroki-Heck, and Sonagashira reactions.
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Paragraph 0142-0144
(2017/10/10)
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- Synthesis of functionalized alkynes via palladium-catalyzed Sonogashira reactions
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A highly efficient protocol for the copper and phosphine free Sonogashira cross-coupling reactions of aryl iodides with terminal alkynes under aerobic conditions has been developed. Using 1 mol % of the palladium-bis(oxazoline) complex, Pd-BOX A, in the p
- Ibrahim, Mansur B.,Ali, Bassam El,Malik, Imran,Fettouhi, Mohammed
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p. 554 - 558
(2016/01/20)
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- Synthesis, crystal structures and catalytic activities of new palladium(II)–bis(oxazoline) complexes
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Palladium–bis(oxazoline) complexes (Pd-BOX-A and Pd-BOX-B) were synthesized and characterized by 1H, 13C NMR, IR and elemental analysis. The molecular structures of the complexes were confirmed by single-crystal X-ray analysis. In both cases, the palladium center is coordinated by the nitrogen atoms of the two oxazoline rings and two chloride ligands in a distorted square planar geometry. Despite the fact that the bis(oxazoline) ligand is achiral, the asymmetrical substitution on the phenyl spacer and the rigid backbone of the complex Pd-BOX-A induce inherent chirality and the compound crystallizes as a racemic mixture. Both complexes were found to be highly effective catalysts for Suzuki–Miyaura, Mizoroki–Heck and Sonogashira cross-coupling reactions. They also show excellent catalytic activities toward carbonylative coupling reactions.
- Ibrahim, Mansur B.,Malik, Imran,Shakil Hussain,Fazal, Atif,Fettouhi, Mohammed,El Ali, Bassam
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p. 739 - 749
(2016/09/13)
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- Fluorescent dye and preparation method and application thereof
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The present invention discloses a thiadiazole-group-containing substituted polyacetylene fluorescent dye with the structural formula shown in the specification, the prepared polymer fluorescent dye is simple in synthesis, can be applied to fluorescent sen
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Paragraph 0016; 0017
(2016/10/07)
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- Nickel-catalyzed three-component domino reactions of aryl grignard reagents, alkynes, and aryl halides producing tetrasubstituted alkenes
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Three-component reaction of aryl Grignard reagents, alkynes, and aryl halides in the presence of 1 mol % of NiCl2 proceeded sequentially through carbomagnesiation of the alkyne followed by cross-coupling of the resulting alkenyl Grignard reagent with aryl halide to give tetrasubstituted alkenes in high yields.
- Xue, Fei,Zhao, Jin,Hor, T. S. Andy,Hayashi, Tamio
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supporting information
p. 3189 - 3192
(2015/03/30)
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- Ambient arylmagnesiation of alkynes catalysed by ligandless nickel(ii)
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A simple and efficient catalytic arylmagnesiation of diarylacetylenes and aryl(alkyl)acetylenes is accomplished by NiCl2·6H2O at r.t. in the absence of stabilising ligands. The corresponding tetra-substituted alkenes can be obtained in good yields by subsequent treatment with different electrophiles. The Royal Society of Chemistry 2013.
- Xue, Fei,Zhao, Jin,Hor, T. S. Andy
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supporting information
p. 10121 - 10123
(2013/10/22)
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- Functionalized polyacetylenes with strong luminescence: "Turn-on" fluorescent detection of cyanide based on the dissolution of gold nanoparticles and its application in real samples
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By dissolution of Au NPs, new polyacetylene-functionalized Au NPs were successfully developed as "turn-on" fluorescent probes for the detection of cyanide sensitively and selectively. The lowest concentration to quantify cyanide ions could be down to 3.0
- Lou, Xiaoding,Zeng, Qi,Zhang, Yi,Wan, Zhaomin,Qin, Jingui,Li, Zhen
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supporting information; experimental part
p. 5581 - 5586
(2012/06/15)
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- Oxidative hydroxylation mediated by alkoxysulfonium ions
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Oxidative hydroxylation of toluene derivatives via alkoxysulfonium ion intermediates was achieved by integration of anodic oxidation and hydrolysis to give benzyl alcohols which are also susceptible to oxidation. Alkenes were also oxidized to give 1,2-diols without overoxidation. The integration of electrochemical oxidative cyclization and hydrolysis was achieved using alkenes bearing a nitrogen atom in an appropriate position to give cyclic β-amino-substituted alcohols.
- Ashikari, Yosuke,Nokami, Toshiki,Yoshida, Jun-Ichi
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supporting information; experimental part
p. 938 - 941
(2012/05/05)
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- Cross-coupling of nonactivated alkyl halides with alkynyl grignard reagents: A nickel pincer complex as the catalyst
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In a pinch: The nickel pincer complex 1 catalyzes the cross-coupling of the title compounds with remarkable substrate scope and functional group tolerance. A nickel/alkynyl species was isolated and shown to be catalytically competent. THF=tetrahydrofuran, O-TMEDA=bis[2-(N,N-dimethylaminoethyl)] ether. Copyright
- Vechorkin, Oleg,Godinat, Aurélien,Scopelliti, Rosario,Hu, Xile
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supporting information; experimental part
p. 11777 - 11781
(2012/01/19)
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- Induced chain alignment, efficient energy transfer, and enhanced light emission in functional poly acetylene-perovskite hybrids
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The hybridization of functional polyacetylenes with lead bromide perovskite was investigated. It was observed that the perovskite induces the nonmesogenic polyactylene chains to align like liquid crystals within the inorganic layers. It was shown that pho
- Hua, Jianli,Li, Zhen,Lam, Jacky W. Y.,Xu, Haipeng,Sun, Jingzhi,Dong, Yuping,Dong, Yongqiang,Qin, Anjun,Yuan, Wangzhang,Chen, Hongzheng,Wang, Mang,Tang, Ben Zhong
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p. 8127 - 8130
(2008/02/01)
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- Pd-catalyzed cross-coupling of alkynylsilanols with iodobenzenes
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Alkynylsilanols were efficiently coupled with iodobenzene derivatives by a Pd catalyst in the presence of TBAF, and the corresponding substituted alkynes could be obtained in good to excellent yields.
- Chang, Sukbok,Yang, Soon Ha,Lee, Phil Ho
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p. 4833 - 4835
(2007/10/03)
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- Asymmetric synthesis of (2S,3S)-3-hydroxy-2-phenylpiperidine via ring expansion
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A catalytic highly enantioselective (99% ee) preparation of N-tert-butyloxycarbonyl-(2S,3S)-3-hydroxy-2-phenyl-piperidine and N-tert-butyloxycarbonyl-(2S)-2-phenyl-piperidin-3-one was developed using an intramolecular epoxide opening followed by ring expa
- Lee, Jaemoon,Hoang, Thoa,Lewis, Stephanie,Weissman, Steven A,Askin, David,Volante,Reider
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p. 6223 - 6225
(2007/10/03)
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- An investigation of l,4,7-tri(4-alkynyl)-l,4,7-triazacyclononanes: Ligand synthesis and metal co-ordination chemistry
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Three triazacyclononanes bearing pendant alkynyl groups [l,4,7-tri(4-pentynyl)-l,4,7-triazacyclononane (ptacn), 1,4,7-tri(5-phenyl-4-pentynyl)-l,4,7-triazacyclononane (pptacn) and 1,4,7-tri(4-hexynyl)-1,4,7-triazacyclononane (4htacn)] have been synthesize
- Baker, Murray V.,Brown, David H.,Skelton, Brian W.,White, Allan H.
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p. 4607 - 4616
(2007/10/03)
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- Formation and behavior of intramolecular N-(styrylalkyl)aniline exciplexes
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The photophysical and photochemical behavior of several aniline spacer - styrene molecules in which the spacer is a short polymethylene chain has been investigated. Long wavelength excitation selectively excites the aniline chromophore which undergoes intramolecular quenching by the styrene to yield an intramolecular exciplex. Exciplex fluorescence is observed for both of the tertiary anilines investigated and for one of the three secondary anilines. More rapid exciplex formation in nonpolar vs. polar solvents is attributed to the necessity of desolvating the polar aniline singlet in polar solvents. Intramolecular adduct formation is the major photochemical process for the secondary anilines, but is highly inefficient for the tertiary anilines. The behavior of the intramolecular aniline-styrene exciplexes is compared to that of the styrene-amine exciplexes previously investigated in this laboratory.
- Lewis, Frederick D.,Wagner-Brennan, Jill M.,Miller, Alan M.
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p. 595 - 604
(2007/10/03)
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- Organocobaloximes in organic synthesis An unusual radical-dependent five-member cyclization
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Visible light photolysis of organocobaloximes R′C=C[CH2]3-CoIII(dmgH)2Py 1-3 (R′ = Ph, TMS, H) with radical trapping agents ArSO2Cl (Ar = Ph, 4-MeC6H4, 4-OMeC6H4
- Das, Indira,Chowdhury, Shantanu,Ravikumar, Krishnan,Roy, Sujit,Gupta, Bhagawan Dass
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p. 101 - 107
(2007/10/03)
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- Organolanthanide-catalyzed intramolecular hydroamination/cyclization of aminoalkynes
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This contribution reports the efficient and regiospecific Cp'2LnCH(SiMe3)2 (Ln = La, Nd, Sm, Lu; Cp' = η5-Me5C5)- and Me2SiCp''2LnCH(SiMe3)2 (Ln = Nd, Sm; Cp'' = η5-Me4C5)-catalyzed hydroamination/cyclization of aliphatic and aromatic aminoalkynes of the formula RC≡C(CH2)(n)NH2 to yield the corresponding cyclic imines RCH2C=N(CH2)(n-1)CH2, where R, n, N(t) h-1 (°C) = Ph, 3, 77 (21°C); Ph, 3, 2830 (60°C); Me, 3, 96 (21°C); CH2=CMeCH2, 3, 20 (21°C); H, 3, 580 (21°C); Ph, 4, 4 (21°C); Ph, 4, 328 (60°C); Ph, 5, 0.11 (60°C); and SiMe3, 3, >7600 (21°C), and of aliphatic secondary amino-alkynes of the formula RC≡C(CH2)3NHR1 to generate the corresponding cyclic enamines RCH=CNR1(CH2)2CH2 where R, R1, N(t) h-1 (°C) = SiMe3, CH2=CHCH2, 56 (21°C); H, CH2=CHCH2, 27 (21°C); SiMe3, CH2=CH(CH2)3, 129 (21°C); and H, CH2=CH(CH2)3, 47 (21°C). Kinetic and mechanistic evidence is presented arguing that the turnover-limiting step is an intramolecular alkyne insertion into the Ln-N bond followed by rapid protonolysis of the resulting Ln-C bond. The use of larger metal ionic radius Cp'2LnCH(SiMe3)2 and more open Me2SiCp''2LnCH(SiMe3)2 complexes as the precatalysts results in a decrease in the rate of hydroamination/cyclization, arguing that the steric demands in the -C≡C- insertive transition state are relaxed compared to those of the analogous aminoolefin hydroamination/cyclization.
- Li,Marks
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p. 9295 - 9306
(2007/10/03)
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- FREE RADICAL REARRANGEMENTS OF ORGANOCOBALOXIMES: ALKYNYL TO CYCLOALKYLIDENE AND HEXENYL TO CYCLOPENTYLMETHYL
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Under irradiation by tungsten light in pyridine solution, several substituted alkylcobaloximes undergo rearrangement to more stable substituted alkyl- or alkenyl-cobaloximes.When the same reactions are carried out in the presence of carbon tetrachloride or chloroform, no rearranged organobaloximes are obtained, but a variety of organic products are obtained derived from the interception of transient organic radicals by the halogenated solvent.The rearrangements are rationalised in terms of a reversible homolysis of the carbon-cobalt bond, rearrangement of the organic radical and recapture by the cobalt(II) fragment to give complexes that are more stable to irradiation than their precursors.
- Bougeard, Peter,Cooksey, Christopher J.,Johnson, Michael D.,Lewin, Melanie J.,Mitchell, Stewart,Owens, Paul A.
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p. 349 - 358
(2007/10/02)
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