- Synthesis of potentially biologically active 6-(1,3-butadiynyl)purines
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1,3-Alkadiynyl(trimethyl)silanes were prepared by the Negishi or Sonogashira reactions of bromoethynyl (trimethyl)silane with several terminal alkynes in 34-75% yield. However, the direct Hiyama coupling of these compounds with 6-iodopurine derivatives ha
- K?ová?ek,Dvo?ák
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- An efficient synthesis of difluoropropargyl bromides
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High yields of γ-alkyl, -silyl and -aryl-substituted difluoropropargyl bromides have been obtained by monitoring concentration and temperature in the reaction between CF2Br2 and γ-substituted lithium acetylide. γ-Silyl substituents afforded the corresponding α,α,α-difluorobromopropargyl alcohols in good yields via cleavage of tetrabutylammonium fluoride in the presence of an aldehyde. Georg Thieme Verlag Stuttgart.
- Xu, Bo,Mae, Masayuki,Hong, Jiyoung A.,Li, Youhua,Hammond, Gerald B.
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- Stereoselective synthesis of (E)- and (Z)-acetals of pent-2-en-4-yn-1-al and related dienynes and dienediynes
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(3E)-5,5-Diethoxypent-3-en-1-yne was stereospecifically prepared by Sonogashira-Linstrumelle cross-coupling between (E)-3-iodoacrolein diethylacetal and (trimethylsilyl)acetylene. The (Z) isomer was obtained by Stille cross-coupling between the corresponding (Z)-vinyltin and 1-bromo-2- (trimethylsilyl)acetylene. In the case of the (E) isomer, transacetalisation occurred without isomerization affording a large variety of (E)-enynals protected as acetals. It has also been shown to be possible to obtain the corresponding (E,E)-dienediyne through sp-sp homo-coupling under appropriate experimental conditions.
- Suzenet, Franck,Parrain, Jean-Luc,Quintard, Jean-Paul
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- Synthesis of Thiomorpholin-3-ones by a Gold-Catalysed Oxidative Cyclisation-Rearrangement Cascade from Ynamides
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A gold-catalyzed oxidative N-cyclisation strategy allows for the preparation of α-aryl thiomorpholin-3-ones from readily assembled ynamides bearing tethered thioethers. A cascade of oxidation, cyclisation and then [2,3]- or [1,2]-sigmatropic rearrangement of the resulting sulfonium ylide proceeds under mild reaction conditions. Cyclisation and intermolecular oxidation are in competition at two different stages of the reaction. The required switch in selectivity between these processes can be managed by combining pyridine N-oxide oxidant with an IPrAuCl-derived catalyst.
- Baker, Thomas,Davies, Paul W.
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- Catalytic Asymmetric Hydroacyloxylation/Ring-Opening Reaction of Ynamides, Acids, and Aziridines
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A highly enantioselective three-component reaction of ynamides with carboxylic acids and 2,2′-diester aziridines has been realized by using a chiral N,N′-dioxide/Ho(OTf)3 complex as a Lewis acid catalyst. The process includes the formation of an α-acyloxyenamide intermediate through the addition of carboxylic acids to ynamides and the following enantioselective nucleophilic addition to in-situ-generated azomethine ylides induced by the chiral catalyst. A range of amino acyloxyenamides are delivered in moderate to good yields with good ee values. In addition, a possible catalytic cycle with a transition model is proposed to elucidate the reaction mechanism.
- Li, Xiangqiang,Zeng, Hongkun,Lin, Lili,Feng, Xiaoming
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supporting information
p. 2954 - 2958
(2021/05/05)
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- Concise Asymmetric Syntheses of Streptazone A and Abikoviromycin**
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Streptazone A and abikoviromycin are alkaloids that both feature an unusual arrangement of reactive functionalities within a compact tricyclic ring system. Here, we report a highly concise asymmetric synthesis of both natural products. The route first constructs another family member, streptazone B1, using a rhodium-catalyzed distal selective allene-ynamide Pauson–Khand reaction. A regio- and enantioselective epoxidation under chiral phase-transfer catalytic conditions directly afforded streptazone A in 8 steps overall. In one additional step, a chemoselective, iridium-catalyzed reduction of the enaminone system then gave abikoviromycin. The reactivity of streptazone A towards a cysteine mimic, N-acetylcysteamine, was studied and revealed unanticipated transformations, including bis-thiol conjugation which may proceed via formation of a cyclopentadienone intermediate. With flexible access to these compounds, studies aimed to identify their direct biological targets are now possible.
- W?rmer, Gustav J.,Villadsen, Nikolaj L.,N?rby, Peter,Poulsen, Thomas B.
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supporting information
p. 10521 - 10525
(2021/03/29)
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- SOLAR CELL DYES FOR COPPER REDOX BASED DYE SENSITIZED SOLAR CELLS AND COMBINATIONS THEREOF
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The present application discloses compounds and compositions, useful in the manufacture of dye-sensitized solar cells and other similar technology.
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Paragraph 0113-0114
(2021/04/10)
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- Catalytic Asymmetric Three-component Hydroacyloxylation/ 1,4-Conjugate Addition of Ynamides
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A highly enantioselective three-component hydroacyloxylation/1,4-conjugate addition of ortho-hydroxybenzyl alcohols, ynamides and carboxylic acids was developed under mild reaction conditions in the presence of a chiral N,N′-dioxide/Sc(OTf)3 complex, which went through in situ generated ortho-quinone methides with α-acyloxyenamides, delivering a range of corresponding chiral α-acyloxyenamides derivatives containing gem(1,1)-diaryl skeletons in moderate to good yields with excellent ee values. The scale-up experiment and further derivation showed the practicality of this catalytic system. In addition, a possible catalytic cycle and transition state model was proposed to elucidate the origin of the stereoselectivity based on X-ray crystal structure of the α-acyloxyenamide intermediate and product.
- Cao, Weidi,Feng, Xiaoming,Jiang, Mingyi,Li, Xiangqiang,Zhan, Tangyu
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supporting information
(2020/06/17)
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- SOLAR CELL DYES FOR COPPER REDOX BASED DYE SENSITIZED SOLAR CELLS AND COMBINATIONS THEREOF
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The present application discloses compounds and compositions, useful in the manufacture of dye-sensitized solar cells and other similar technology.
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Paragraph 00114
(2020/02/06)
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- PYRROLO[2,3-D]PYRIMIDIN-2-ONE ANTIMICROBIAL COMPOUNDS
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The present disclosure relates generally to the field of antimicrobial compounds and to methods of making and using them. In some embodiments, the present disclosure provides pyrrolo[2,3-d]pyrimidin-2-ones useful for treating, preventing, reducing the risk of, and delaying the onset of microbial infections in humans and animals.
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Page/Page column 83
(2020/07/05)
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- COMPLEX
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PROBLEM TO BE SOLVED: To provide a substance that can be used in a simple quantitative method for desmosines. SOLUTION: In the complex of the present invention, desmosine is bound to a protein directly or via a linking group at the side chain terminal of the 4-position of the pyridine ring of desmosine. SELECTED DRAWING: None COPYRIGHT: (C)2020,JPOandINPIT
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Paragraph 0058-0060
(2019/11/03)
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- Direct Assembly of Polysubstituted Propiolamidinates via Palladium-Catalyzed Multicomponent Reaction of Isocyanides
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A straightforward approach for the assembly of different polysubstituted propiolamidnates via palladium-catalyzed multicomponent reaction of isocyanides, haloalkynes, and amines has been reported in which the C(sp)-C(sp2) and C(sp2)a
- Li, Meng,Fang, Songjia,Zheng, Jia,Jiang, Huanfeng,Wu, Wanqing
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supporting information
p. 8439 - 8443
(2019/10/16)
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- Diastereoselective Copper-Mediated Cross-Couplings between Stereodefined Secondary Alkylcoppers with Bromoalkynes
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A copper(I)-mediated cross-coupling of stereodefined secondary alkyllithiums with bromoalkynes provided stereodefined alkynes with high diastereoselectivity (dr up to 98:2). This cross-coupling was extended to various secondary alkyllithiums bearing a remote oxygen functionality, and the alkyne synthesis was also performed with optically enriched alkyl iodides (up to 99% ee) providing, after cross-coupling, alkynes bearing two stereocenters (dr = 93:7; up to 99% ee).
- Skotnitzki, Juri,Morozova, Varvara,Knochel, Paul
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supporting information
p. 2365 - 2368
(2018/04/30)
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- Silyl Group-Directed 6-exo-dig Iodocyclization of Homopropargylic Carbamates and Amides
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Iodocyclization of silyl group-substituted homopropargylic carbamates and amides proceeded via 6-exo-dig mode to afford 6-vinylene-4,5-dihydro-1,3-oxazines in moderate to quantitative yields. This is the first report for silyl group-solely directed iodocy
- Okitsu, Takashi,Nakahigashi, Hikaru,Sugihara, Ryosuke,Fukuda, Ikki,Tsuji, Saki,In, Yasuko,Wada, Akimori
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supporting information
p. 18638 - 18642
(2018/12/04)
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- Copper-Catalyzed Alkynylboration of Alkenes with Diboron Reagents and Bromoalkynes
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An efficient method for the synthesis of homopropargylboronates by copper-catalyzed alkynylboration of alkenes with diboron reagents and bromoalkynes has been developed. The alkynylboration reaction features high selectivity and efficiency, mild reaction conditions, wide substrate scope, and functional-group compatibility, and is a highly attractive complement to existing methods for the synthesis of homopropargylboronates. Both the boryl and alkynyl groups are good potential functional groups for the subsequent manipulations that provide access to a variety of important molecule structures.
- Gong, Tian-Jun,Yu, Shang-Hai,Li, Kuan,Su, Wei,Lu, Xi,Xiao, Bin,Fu, Yao
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supporting information
p. 2884 - 2888
(2017/10/30)
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- Ynamide Carbopalladation: A Flexible Route to Mono-, Bi- and Tricyclic Azacycles
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Bromoenynamides represent precursors to a diversity of azacycles by a cascade sequence of carbopalladation followed by cross-coupling/electrocyclization, or reduction processes. Full details of our investigations into intramolecular ynamide carbopalladation are disclosed, which include the first examples of carbopalladation/cross-coupling reactions using potassium organotrifluoroborate salts; and an understanding of factors influencing the success of these processes, including ring size, and the nature of the coupling partner. Additional mechanistic observations are reported, such as the isolation of triene intermediates for electrocyclization. A variety of hetero-Diels-Alder reactions using the product heterocycles are also described, which provide insight into Diels-Alder regioselectivity.
- Campbell, Craig D.,Greenaway, Rebecca L.,Holton, Oliver T.,Walker, P. Ross,Chapman, Helen A.,Russell, C. Adam,Carr, Greg,Thomson, Amber L.,Anderson, Edward A.
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supporting information
p. 12627 - 12639
(2015/09/01)
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- Nucleophile-selective cross-coupling reactions with vinyl and alkynyl bromides on a dinucleophilic aromatic substrate
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A nucleophile-selective cross-coupling reaction on an aromatic compound bearing two metal groups, Bpin and SnMe3, has been developed. Previously, only aryl bromides and iodides could be used as electrophilic components, but in this work, the scope could be extended to vinyl and alkynyl bromides as electrophiles. This means that the roles typical in Sonogashira couplings or Heck reactions of the aromatic ring as the dielectrophile coupling to vinyl and alkynyl metal species are reversed, which presents a new tool for organic synthesis. The first nucleophilic site to react is the stannyl group, and subsequently, a Suzuki-Miyaura cross-coupling reaction can take place on the same molecule.
- He, Lu-Ying,Schulz-Senft, Mathias,Thiedemann, Birk,Linshoeft, Julian,Gates, Paul J.,Staubitz, Anne
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supporting information
p. 2498 - 2502
(2015/04/22)
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- Gold-Catalyzed Intermolecular Nitrene Transfer from 2H-Azirines to Ynamides: A Direct Approach to Polysubstituted Pyrroles
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(Chemical Equation Presented). An effective gold-catalyzed intermolecular nitrene transfer by the reaction of 2H-azirines and ynamides is reported, which provides highly substituted pyrroles in a straightforward manner. This transformation proceeds under mild conditions and gives the polysubstituted pyrroles in good-to-excellent yields. Preliminary results indicate that a nongold carbenoid pathway is preferred for current pyrrole synthesis.
- Zhu, Lei,Yu, Yinghua,Mao, Zhifeng,Huang, Xueliang
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supporting information
p. 30 - 33
(2015/07/28)
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- Synthesis of 2-iodoynamides and regioselective [2+2] cycloadditions with ketene
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The first synthesis of 2-iodoynamides is described as well as the first [2+2] cycloadditions of ketene with iodo alkynes.
- Wang, Yu-Pu,Danheiser, Rick L.
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scheme or table
p. 2111 - 2114
(2011/05/09)
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- Palladium-catalyzed bromoalkynylation of C-C double bonds: Ring-structure-dependent synthesis of 7-alkynyl norbornanes and cyclobutenyl halides
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Strain versus flexibility: The palladium-catalyzed reaction of haloalkynes with norbornene derivatives leads to 7-alkynyl norbornane products (see scheme). Key to the success of this reaction is the formation of a "bridging" palladium species, which can rearrange to result in a C-7 functionalization. The ring-structure-dependent [2+2] cycloaddition of haloalkynes with cyclooctene has been achieved in moderate to good yields under similar conditions. Copyright
- Li, Yibiao,Liu, Xiaohang,Jiang, Huanfeng,Liu, Bifu,Chen, Zhengwang,Zhou, Peng
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supporting information; experimental part
p. 6341 - 6345
(2011/09/13)
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- Synthetic and structural studies on C-ethynyl- and C-bromo-carboranes
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A high-yield preparation of the C-monoethynyl para-carborane, 1-Me 3SiCC-1,12-C2B10H11, from C-monocopper para-carborane and 1-bromo-2-(trimethylsilyl)ethyne, BrCCSiMe 3 is reported. The low-yield preparation of 1,12-(Me 3SiCC)2-1,12-C2B10H10 from the C,C′-dicopper para-carborane derivative with 1-bromo-2- (trimethylsilyl)ethyne, BrCCSiMe3, has been re-investigated and other products were identified including the C-monoethynyl-carborane 1-Me 3SiCC-1,12-C2B10H11 and two-cage assemblies generated from cage-cage couplings. The contrast in the yields of the monoethynyl and diethynyl products is due to the highly unfavourable coupling process between 1-RCC-12-Cu-1,12-C2B10H10 and the bromoalkyne. The ethynyl group at the cage carbon C(1) strongly influences the chemical reactivity of the cage carbon at C(12) - the first example of the 'antipodal effect' affecting the syntheses of para-carborane derivatives. New two-step preparations of 1-ethynyl- and 1,12-bis(ethynyl)-para-carboranes have been developed using a more readily prepared bromoethyne, 1-bromo-3-methyl-1- butyn-3-ol, BrCCCMe2OH. The molecular structures of the two C-monoethynyl-carboranes, 1-RCC-1,12-C2B10H11 (R = H and Me3Si), were experimentally determined using gas-phase electron diffraction (GED). For R = H (RG = 0.053) a model with C5v symmetry refined to give a CC bond distance of 1.233(5) A. For R = Me3Si (RG = 0.048) a model with Cs symmetry refined to give a CC bond distance of 1.227(5) A. Molecular structures of 1,12-Br2-1,12-C2B10H 10, 1-HCC-12-Br-1,12-C2B10H10 and 1,12-(Me3SiCC)2-1,12-C2B10H 10 were determined by X-ray crystallography. Substituents at the cage carbon atoms on the C2B10 cage skeleton in 1-X-12-Y-1,12-C2B10H10 derivatives invariably lengthen the cage C-B bonds. However, the subtle substituent effects on the tropical B-B bond lengths in these compounds are more complex. The molecular structures of the ethynyl-ortho-carborane, 1-HCC-1,2-C2B 10H11 and the ethene, trans-Me3SiBrCCSiMe 3Br are also reported. The Royal Society of Chemistry 2006.
- Fox, Mark A.,Cameron, Audrey M.,Low, Paul J.,Paterson, Michael A.J.,Batsanov, Andrei S.,Goeta, Andres E.,Rankin, David W.H.,Robertson, Heather E.,Schirlin, Julien T.
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p. 3544 - 3560
(2007/10/03)
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- Construction of terminal conjugated enynes: Regio- and stereoselective syntheses of 3-alken-1-ynes and 1-trimethylsilyl-3-alken-1-ynes from alkenyldialkylboranes and (trimethylsilyl)ethynyl bromide
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The cross-coupling reaction of (E)- and (Z)-1-alkenyldialkylboranes with (trimethylsilyl)ethynyl bromide proceeds in the presence of a base and a catalytic amount of Cu(acac)2 under very mild conditions to provide conjugated enynes whose carbon
- Hoshi, Masayuki,Shirakawa, Kazuya
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p. 1101 - 1104
(2007/10/03)
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- A new organic nanoporous architecture: Dumb-bell-shaped molecules with guests in parallel channels
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A new type of dumb-bell-shaped host molecule (6-8) has been synthesised, of which 1,8-bis((1)-adamantyl)-1,3,5,7-octatetrayne (8 = BAOT) forms an open porous architecture when cocrystallised with a number of typical solvent molecules. Adamantyl substituents attached to a tetraalkyne spacer build up the walls of parallel channels wherein guest molecules are aligned. Surprisingly, the tetraalkyne unit is significantly bent. Desolvation experiments provide evidence for a reversible inclusion of guests. In the case of the inclusion of 2-butanone, a partial substitution by symmetrical and asymmetrical long-chain chromophores during crystallisation was possible. Stained crystals showed optical frequency doubling. The crystal structure analysis revealed a centric space group, although considerable translational and orientational disorder was present. Application of scanning pyroelectric microscopy revealed that the growth of inclusion compounds with 2-butanone produced polar ordering of guest molecules, which were aligned in two macro-domains of opposing polarity. The resulting orientation of the carbonyl dipoles is in agreement with the theoretical prediction of a Markov model of spontaneous polarity formation based on molecular recognition processes on growing crystal faces. The present case represents a new example of a property-driven supramolecular synthesis.
- Mueller, Torsten,Hulliger, Juerg,Seichter, Wilhelm,Weber, Edwin,Weber, Thomas,Wuebbenhorst, Michael
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- Terminal 1-halo and 1-pseudohalo-1-alkynes via Bis(trimethylsilyl)peroxide (BTMSPO) promoted Umpolung transfer of halides and pseudohalides
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Reaction of terminal acetylenes with readily available and inexpensive copper and zinc halides and pseudo-halides and BTMSPO has been found to be an effective and general route for obtaining, in the absence of bases and under mild conditions, 1-halo and 1-pseudohalo-1-alkynes in generally good yields.
- Casarini,Dembech,Reginato,Ricci,Seconi
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p. 2169 - 2170
(2007/10/02)
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- Improvements relating to pesticides
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Bicyclo-octane pesticides have the formula where Z is CH2CH2, CH2O, CH2S, -COCH2 or CH(OR8)CH2 where R8 is H, alkyl, acyl or carbamoyl; Y and Y1 are O or S(O)mwhere m is 0, 1 or 2; R is a specified substituted or unsubstituted aliphatic or cycloaliphatic hydrocarbon groups or a phenyl group, R1 and R3 are H, or specified substituted or unsubstituted aliphatic hydrocarbon groups or R1 is a carboalkoxy, cyano or gem dimethyl group when R3 is H or R and R1, together with the carbon atoms to which they are attached form a carbocyclic ring; and R2 is a phenyl group substituted at position 4 by -(C≡C)nR5 and optionally at other positions by specified substituents where n is 1 or 2 and R5 is I, H, alkyl optionally substituted, carboalkoxy, or a trisubstituted tin or trisubstituted silicon group. Various methods of synthesis are given.
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- Halogenation of alkynes and alkynylsilanes
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Halogenation of alkynes has given 1,2-dihalogenoalkenes in good yields.Bromination of alkynylsilanes has given 1,2-dibromovinylsilanes, and reactions with iodine chloride mainly iodoalkynes.
- Al-Hassan, Mohammed I.
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p. 183 - 186
(2007/10/02)
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- Neue Anwendungsmoeglichkeiten fuer schwere Hauptgruppenelemente in der organischen Synthese
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Ausser Elementen der 2.Reihe und einem Element der 3.Reihe des Periodensystem - Si,P,S bzw.Se -, deren Organoelementgruppen wie Me3Si und Ph3P+ sich vielfach bewaehrten, koennen in der organischen Synthese auch andere Elemente der 3. sowie der
- Kauffmann, Thomas
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p. 401 - 420
(2007/10/02)
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