- Synthesis, identification and application of aldehyde reactive dyes
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Nine aldehyde reactive dyes, designated D1- D9, were synthesized. Among them, D1 and D2 were synthesized by "grafting" alizarin red and alizarin yellow GG, respectively, to the α-C of n-butyl-aldehyde; D3 and D4 were synthesized by "grafting" alizarin red and alizarin yellow GG, respectively, to the methyl-C of 4-methyl-cinnamaldehyde; D5- D9 were synthesized by "grafting" alizarin red, alizarin yellow GG or self-prepared colorants to the α-C of glutaraldehyde. UV-Vis, FTIR, ESI-MS, elemental analysis and 1H NMR were applied to identify the target products. Aluminum-tanned wet-white sheep leather was chosen as substrate for the application experiments, and their four dyeing property indexes, i.e., substantivity (S), exhaustion (E), fixation (F) and reactivity (R) were measured. The results indicated that, without adding of neutral salts and under mild conditions (T = 35-45 °C, pH = 4.0-6.5), all these dyes could dye wet-white leather within 1.5 h, and the dyed leather possessed a satisfactory washing-fastness.
- Chen, Xiao,Ding, Keyi,Jun, Liu
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- Chain Walking as a Strategy for Carbon-Carbon Bond Formation at Unreactive Sites in Organic Synthesis: Catalytic Cycloisomerization of Various 1,n-Dienes
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Carbon-carbon bond formation at unreactive sp3-carbons in small organic molecules via chain walking was achieved for the palladium-catalyzed cycloisomerization of 1,n-dienes. Various 1,n-dienes (n = 7-14) such as those containing cyclic alkenes, acyclic internal alkenes, and a trisubstituted alkene can be used for the chain-walking cycloisomerization/hydrogenation process, and five-membered ring compounds including simple cyclopentane and pyrrolidine derivatives can easily be prepared. Chain walking over a tertiary carbon was also found to be possible in the cycloisomerization. It is not necessary for the linker portion of the diene to contain a quaternary center, and diene substrates with two alkene moieties linked by a tertiary carbon or a nitrogen atom can also be used as substrates. Column chromatography using silica gel containing silver nitrate was found to be effective for isolating some of the cycloisomerization products without hydrogenation. Deuterium-labeling experiments provided direct evidence to show that the reaction proceeds via a chain-walking mechanism.
- Hamasaki, Taro,Aoyama, Yuka,Kawasaki, Junichi,Kakiuchi, Fumitoshi,Kochi, Takuya
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- Synthesis of 1-arylcycloalkenamines by intramolecular arylation of lithiated ureas
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The deprotonation of N′-arylurea derivatives of cyclohexenamines by alkyllithiums leads to migration of the N′-aryl substituent from N′ to the allylic position α to N via rearrangement of a urea-stabilised allyllithium intermediate. The product ureas may be solvolysed to reveal 1-arylcyclohexenamines.
- Tait, Michael B.,Ottersbach, Philipp A.,Tetlow, Daniel J.,Clayden, Jonathan
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- N-(4-Methoxyphenyl)-substituted bicyclic isothioureas: effect on morphology of cancer cells
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Bicyclic isothioureas of N-(4-methoxyphenyl)-2-aminocycloalkane[d]thiazole type were obtained using intramolecular electrophilic cyclization of N-(cycloalk-2-enyl)-N′-(4-methoxyphenyl)thioureas. Isothiourea fused with sevenmembered ring caused noticeable
- Alexeev, Alexander A.,Evdokimova, Anna V.,Kuznetsov, Sergei A.,Milaeva, Elena R.,Nurieva, Evgeniya V.,Zefirova, Olga N.
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p. 288 - 290
(2021/06/07)
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- Catalytic Living Ring Opening Metathesis Polymerisation: The Importance of Ring Strain in Chain Transfer Agents
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A recently developed catalytic living ring opening metathesis polymerisation (ROMP) was investigated using a series of reversible chain transfer agents (CTA) carrying either cyclopentene or cyclohexene rings, differing only in ring strain. All cyclopentene derivatives examined showed significantly faster reaction rates than the corresponding cyclohexene derivatives. This resulted in lower molecular weight dispersities and better control of the molecular weight for the cyclopentene compared to the cyclohexene CTAs. Both Grubbs’ second and third generation catalysts could be employed in catalytic living ROMP using cyclopentene CTA derivatives. The kinetics of different CTAs were studied, block copolymers were synthesised and residual ruthenium quantified by ICP-OES. All polymers were fully characterised by NMR, GPC and MALDI-ToF mass spectrometry. The new cyclopentene CTAs are readily synthesised in a few straightforward steps and provide faster reaction kinetics than all previously reported reversible CTAs.
- Liu, Peng,Yasir, Mohammad,Kilbinger, Andreas F. M.
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supporting information
p. 15278 - 15282
(2019/09/17)
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- (Guanidine)copper Complex-Catalyzed Enantioselective Dynamic Kinetic Allylic Alkynylation under Biphasic Condition
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Highly enantioselective allylic alkynylation of racemic bromides under biphasic condition is furnished in this report. This approach employs functionalized terminal alkynes as pro-nucleophiles and provides 6- and 7-membered cyclic 1,4-enynes with high yields and excellent enantioselectivities (up to 96% ee) under mild conditions. Enantioretentive derivatizations highlight the synthetic utility of this transformation. Cold-spray ionization mass spectrometry (CSI-MS) and X-ray crystallography were used to identify some catalytic intermediates, which include guanidinium cuprate ion pairs and a copper-alkynide complex. A linear correlation between the enantiopurity of the catalyst and reaction product indicates the presence of a copper complex bearing a single guanidine ligand at the enantio-determining step. Further experimental and computational studies supported that the alkynylation of allylic bromide underwent an anti-SN2′ pathway catalyzed by nucleophilic cuprate species. Moreover, metal-assisted racemization of allylic bromide allowed the reaction to proceed in a dynamic kinetic fashion to afford the major enantiomer in high yield.
- Cui, Xi-Yang,Ge, Yicen,Tan, Siu Min,Jiang, Huan,Tan, Davin,Lu, Yunpeng,Lee, Richmond,Tan, Choon-Hong
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supporting information
p. 8448 - 8455
(2018/06/22)
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- Synthesis of pentacyclic compounds via intramolecular [3 + 2] photocycloaddition of cycloalkene linked naphthalenes
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Intramolecular photocycloaddition reactions of cycloalkene linked naphthalenes lead to formation of pentacyclic compounds in a high yielding and stereoselective manner. Intramolecular [2 + 2] cycloadducts are formed initially in photoreactions of cycloalkene linked 1-cyanonaphthalenes. The initially formed intramolecular [2 + 2] cycloadducts absorb light at wavelengths used to promote the photochemical reactions and, as a result, they undergo efficient photocycloreversion to regenerate the starting substrates. In a less efficient competing process, the cycloalkene linked 1-cyanonaphthalenes react to form [3 + 2] intramolecular photoadducts, which do not absorb incident light under the conditions used. Consequently, these photoadducts become the major products in these processes. The relative configuration of the major diastereomers of the pentacyclic products formed from photoreactions of cyclopentene linked naphthalenes (cis-cis) differ from those (cis-trans) arising from the cyclooctene linked substrates. The results of theoretical calculations, which show that steric factors govern the preferred facial mode of intramolecular addition, are in good agreement with the stereochemical course of these photoreactions.
- Maeda, Hajime,Uesugi, Tomoya,Fujimoto, Yasufumi,Mukae, Hirofumi,Mizuno, Kazuhiko
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p. 198 - 206
(2017/02/10)
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- Inhibitory Kappa B Kinase α (IKKα) Inhibitors That Recapitulate Their Selectivity in Cells against Isoform-Related Biomarkers
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IKKβ plays a central role in the canonical NF-kB pathway, which has been extensively characterized. The role of IKKα in the noncanonical NF-kB pathway, and indeed in the canonical pathway as a complex with IKKβ, is less well understood. One major reason for this is the absence of chemical tools designed as selective inhibitors for IKKα over IKKβ. Herein, we report for the first time a series of novel, potent, and selective inhibitors of IKKα. We demonstrate effective target engagement and selectivity with IKKα in U2OS cells through inhibition of IKKα-driven p100 phosphorylation in the noncanonical NF-kB pathway without affecting IKKβ-dependent IKappa-Bα loss in the canonical pathway. These compounds represent the first chemical tools that can be used to further characterize the role of IKKα in cellular signaling, to dissect this from IKKβ and to validate it in its own right as a target in inflammatory diseases.
- Anthony, Nahoum G.,Baiget, Jessica,Berretta, Giacomo,Boyd, Marie,Breen, David,Edwards, Joanne,Gamble, Carly,Gray, Alexander I.,Harvey, Alan L.,Hatziieremia, Sophia,Ho, Ka Ho,Huggan, Judith K.,Lang, Stuart,Llona-Minguez, Sabin,Luo, Jia Lin,McIntosh, Kathryn,Paul, Andrew,Plevin, Robin J.,Robertson, Murray N.,Scott, Rebecca,Suckling, Colin J.,Sutcliffe, Oliver B.,Young, Louise C.,Mackay, Simon P.
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p. 7043 - 7066
(2017/09/07)
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- Step-Economical Photoassisted Diversity-Oriented Synthesis: Sustaining Cascade Photoreactions in Oxalyl Anilides to Access Complex Polyheterocyclic Molecular Architectures
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Atom- and step-economy in photoassisted diversity-oriented synthesis (DOS) is achieved with a versatile oxalyl linker offering rapid access to complex alkaloid mimics in very few experimentally simple steps: (i) it allows for fast tethering of the photoac
- Kuznetsov, Dmitry M.,Kutateladze, Andrei G.
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supporting information
p. 16584 - 16590
(2017/11/28)
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- Preparation of polycyclic compounds by intramolecular photospirocyclization and photocycloaddition reactions of 4-alkenyl-1-cyanonaphthalene derivatives
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Photoreactions of 4-pentenyl-1-cyanonaphthalenes yield spirocyclic products along with [4?+?2] cycloadducts. Photoreactions of 5-phenyl derivatives produce a product having tricyclo[6.3.0.01,4]undecadiene skeleton. Formation of angular triquinanes takes place in photoreactions of cycloalkene-linked cyanonaphthalenes. The observation demonstrates that π–π arene ring interactions, steric hindrance, and suitable locations of reaction sites in syn and anti singlet exciplexes govern the modes followed in intramolecular photoreactions of 4-alkenyl-1-cyanonaphthalenes.
- Maeda, Hajime,Wada, Hidenori,Mukae, Hirofumi,Mizuno, Kazuhiko
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- Stereoselective synthesis of carbocyclic analogues of the nucleoside Q precursor (PreQ0)
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A convergent and stereoselective synthesis of chiral cyclopentyl- and cyclohexylamine derivatives of nucleoside Q precursor (PreQ0) has been accomplished. This synthetic route allows for an efficient preparation of 4-substituted analogues with
- Llona-Minguez, Sabin,Mackay, Simon P.
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supporting information
p. 1333 - 1338
(2014/07/22)
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- Precision vinyl acetate/ethylene (VAE) copolymers by ROMP of acetoxy-substituted cyclic alkenes
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Precision linear vinyl acetate/ethylene (VAE) copolymers containing acetoxy groups on precisely every eighth backbone carbon were synthesized by ring-opening metathesis polymerization (ROMP) of racemic 3-acetoxy cyclooctene (3AcCOE) followed by hydrogenation. The use of enantiomerically pure 3AcCOE resulted in an optically active polyalkenamer that afforded isotactic precision VAE materials after hydrogenation. Both of these VAE polymers are semicrystalline (by differential scanning calorimetry and wide-angle X-ray scattering) due to their high degrees of regioregularity and the isotactic VAE samples exhibited a higher apparent degree of crystallinity and melting point compared to the atactic version. In contrast, analogous linear VAE copolymers derived from ROMP-hydrogenation of racemic 4- or 5-acetoxy cyclooctenes were regio-irregular and completely amorphous. The ROMP-hydrogenation of 3-acetoxy cycloheptene also affords precision linear VAE copolymers with acetoxy groups on every seventh carbon, but this polymer was noncrystalline. Mechanical characterization showed that the precision 3AcCOE-derived VAE samples possess improved mechanical properties compared to the compositionally similar commercial VAE copolymers produced by radical copolymerization.
- Zhang, Jihua,Matta, Megan E.,Martinez, Henry,Hillmyer, Marc A.
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p. 2535 - 2543
(2013/06/04)
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- Diastereodivergent hydroxyfluorination of cyclic and acyclic allylic amines: Synthesis of 4-deoxy-4-fluorophytosphingosines
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A diastereodivergent hydroxyfluorination protocol enabling the direct conversion of some conformationally biased allylic amines to the corresponding diastereoisomeric amino fluorohydrins has been developed. Sequential treatment of a conformationally biased allylic amine with 2 equiv of HBF 4·OEt2 followed by m-CPBA promotes epoxidation of the olefin on the face proximal to the amino group under hydrogen-bonded direction from the in situ formed ammonium ion. Regioselective and stereospecific epoxide ring-opening by transfer of fluoride from a BF 4- ion (an SN2-type process at the carbon atom distal to the ammonium moiety) then occurs in situ to give the corresponding amino fluorohydrin. Alternatively, an analogous reaction using 20 equiv of HBF4·OEt2 results in preferential epoxidation of the opposite face of the olefin, which is followed by regioselective and stereospecific epoxide ring-opening by transfer of fluoride from a BF 4- ion (an SN2-type process at the carbon atom distal to the ammonium moiety). The synthetic utility of this methodology is demonstrated via its application to a synthesis of 4-deoxy-4-fluoro-l-xylo- phytosphingosine and 4-deoxy-4-fluoro-l-lyxo-phytosphingosine, each in five steps from Garner's aldehyde.
- Cresswell, Alexander J.,Davies, Stephen G.,Lee, James A.,Morris, Melloney J.,Roberts, Paul M.,Thomson, James E.
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p. 7262 - 7281
(2012/10/30)
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- Ammonium-directed olefinic epoxidation: Kinetic and mechanistic insights
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The ammonium-directed olefinic epoxidations of a range of differentially N-substituted cyclic allylic and homoallylic amines (derived from cyclopentene, cyclohexene, and cycloheptene) have been investigated, and the reaction kinetics have been analyzed. The results of these studies suggest that both the ring size and the identity of the substituents on nitrogen are important in determining both the overall rate and the stereochemical outcome of the epoxidation reaction. In general, secondary amines or tertiary amines with nonsterically demanding substituents on nitrogen are superior to tertiary amines with sterically demanding substituents on nitrogen in their ability to promote the oxidation reaction. Furthermore, in all cases examined, the ability of the (in situ formed) ammonium substituent to direct the stereochemical course of the epoxidation reaction is either comparable or superior to that of the analogous hydroxyl substituent. Much slower rates of ring-opening of the intermediate epoxides are observed in cyclopentene-derived and cycloheptene-derived allylic amines as compared with their cyclohexene-derived allylic and homoallylic amine counterparts, allowing for isolation of these intermediates in both of the former cases.
- Brennan, Meabh B.,Claridge, Timothy D.W.,Compton, Richard G.,Davies, Stephen G.,Fletcher, Ai M.,Henstridge, Martin C.,Hewings, David S.,Kurosawa, Wataru,Lee, James A.,Roberts, Paul M.,Schoonen, Anne K.,Thomson, James E.
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p. 7241 - 7261
(2012/11/07)
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- Copper-catalyzed asymmetric allylic alkylation of racemic cyclic substrates: Application of dynamic kinetic asymmetric transformation (DYKAT)
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The copper-catalyzed asymmetric allylic alkylation (AAA) is of great interest in organic synthesis. This reaction was extensively studied using a broad range of substrates, ligands and organometallic reagents. However, the use of racemic substrates was still limited. Although some processes of kinetic resolution are reported in the literature, no examples of quantitative deracemization are described as is the case for the Pd-catalyzed allylic alkylation. We present here a full account of our investigations through the development of the first example of such a process in copper-catalyzed AAA. High enantioselectivities (up to 99% ee), scope of the reaction and mechanistic considerations are reported herein.
- Langlois, Jean-Baptiste,Alexakis, Alexandre
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supporting information; experimental part
p. 447 - 457
(2010/06/13)
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- Black-light-induced radical/ionic hydroxymethylation of alkyl iodides with atmospheric co in the presence of tetrabutylammonium borohydride
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(Figure Presented) Tin-free radical/ionic hydroxymethylation of secondary and tertiary alkyl iodides proceeded efficiently in the presence of tetrabutylammonium borohydride as the hydrogen source under atmospheric pressure of CO In conjunction with photoirradiation using black light. Two possible mechanisms were proposed, both of which involve hybrid radical/ionic processes.
- Kobayashi, Shoji,Kawamoto, Takuji,Uehara, Shohei,Fukuyama, Takahide,Ryu, Ilhyong
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supporting information; experimental part
p. 1548 - 1551
(2010/07/06)
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- Selective approach toward multifunctionalized lactams by lewis acid promoted PhSe group transfer radical cyclization
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We have developed a regiospecific and highly stereoselective strategy for constructing the five-/six-membered monocyclic and bicyclic nitrogen heterocycle skeletons using PhSe group transfer radical cyclization of α-phenylseleno amido esters promoted by a Lewis acid (e.g., Yb(OTf)3) under UV irradiation. We obtained 5-/6-exo-trig mode cyclization products for the N-allyl/homoallyl substrates, whereas the enamide substrate gave 5-endo-trig ring closure.
- Yu, Jin-Di,Ding, Wei,Lian, Gao-Yan,Song, Ke-Sheng,Zhang, Dan-Wei,Gao, Xiang,Yang, Dan
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supporting information; experimental part
p. 3232 - 3239
(2010/08/19)
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- Ammonium-directed oxidation of cyclic allylic and homoallylic amines
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(Chemical Equation Presented) The ammonium-directed olefinic oxidation of a range of cyclic allylic and homoallylic amines has been investigated. Functionalization of a range of allylic 3-(N,N-dibenzylamino)cycloalk-1-enes with m-CPBA in the presence of Cl3CCO2H gives exclusively the corresponding syn-epoxide for the 5-membered ring (>99:1 dr), the anti-epoxide for the 8-membered ring (>99:1 dr), and predominantly the anti-epoxide for the 7-membered ring (94:6 dr). Oxidation of the homoallylic amines 3-(Nbenzylamino) methylcyclohex-1-ene and 3-(N,N-dibenzylamino)methylcyclohex-1-ene gave, in both cases, the correspondingN-protected 1,2-anti-2,3-syn-3-aminomethylcyclohexane- 1,2-diol with high levels of diastereoselectivity (g90:10 dr). The versatile synthetic intermediates resulting from these oxidation reactions are readily transformed into a range of amino diols.
- Bond, Christopher W.,Cresswell, Alexander J.,Davies, Stephen G.,Fletcher, Ai M.,Kurosawa, Wataru,Lee, James A.,Roberts, Paul M.,Russell, Angela J.,Smith, Andrew D.,Thomson, James E.
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supporting information; experimental part
p. 6735 - 6748
(2009/12/31)
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- Use of cyclic allylic bromides in the zinc-mediated aqueous Barbier-Grignard reaction
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The zinc-mediated aqueous Barbier-Grignard reaction of cyclic allylic bromide substrates with various aldehydes and ketones to afford homoallylic alcohols was investigated. Aromatic aldehydes and ketones afforded adducts in good yields (66-90%) and with good diastereoselectivities. Non-aromatic aldehydes also reacted well under these conditions, but only poor yields were obtained with non-aromatic ketones. Regioselectivity was high when some substituted cyclic allylic bromides were investigated.
- Breton, Gary W.,Shugart, John H.,Hughey, Christine A.,Conrad, Brian P.,Perala, Suzanne M.
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p. 655 - 662
(2007/10/03)
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- X=Y-ZH Systems as potential 1,3-dipoles. Part 52: Fused-ring forming electrophile induced oxime→nitrone→cycloaddition cascades
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Electrophile induced cyclisation of oximes onto endocyclic alkenes and exo-methylene cycloalkanes occurs stereo- and regio-specifically generating cis-fused bicyclic nitrones in good yield. Subsequent facially selective cycloaddition with N-methylmaleimid
- Ali Dondas,Grigg, Ronald,Thibault, Sylvie
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p. 7035 - 7045
(2007/10/03)
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- Intramolecular acryloxypalladation. Stereospecific synthesis of ring fused unsaturated α-methylene γ-butyrolactones.
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The intramolecular carboxypalladation reaction [Pd(OAc)2 5 mol%, NaOAc 2 eq, O2, THF, rt] of 2-(2-Cycloalken-1-yle) propenoic acids yields ring fused α-methylene γ-butyrolactones with good yields. (75-80%).
- Jabre-Truffert, Sylvaine,Waegell, Bernard
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p. 835 - 836
(2007/10/03)
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- Enantioselective synthesis of 1S, 3S, 5S- and 1R, 3S, 5R-2-Azabicyclo[3.3.0]octane-3-carboxylic acid starting from L-serine
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(1S, 3S, 5S)- and (1R, 3S, 5R)-2-Azabicyclo[3.3.0]octane-3-carboxylic acid have been synthesized by intramolecular radical cyclisation of methyl 2-(S)-[N-benzyloxycarbonyl-N-(2-cyclopenten-l-yl)amino]-3-iodopropionate and subsequent reactions.
- Urbach, Hansjoerg,Henning, Rainer
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p. 957 - 965
(2007/10/02)
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