- Unusual titanium-induced McMurry coupling of 4-oxo-4H-chromene-2-carbaldehydes enroute to bis-chromones
-
Ti/Zn-mediated McMurry coupling of a series of 4-oxo-4H-chromene-2-carbaldehydes afforded unusual chemoselective CH2-CH2tethered bis-chromones. Studying the reaction parameters and reagents further confirmed that the formation of unexpected coupled products is selective to 4-oxo-4H-chromene-2-carbaldehydes. This methodology demonstrated a simple and efficient route for the synthesis of bis-chromones.
- Yerrabelly, Jayaprakash Rao,Bathini, Pavan Kumar,Yerrabelly, Hemasri,Vadapalli, Kishore
-
p. 4705 - 4709
(2021/03/22)
-
- Synthesis method of diarylethene
-
The invention discloses a synthetic method of diarylethene. The method comprise the following steps: potassium acetate and ultrapure water are added to a dry anaerobic tube, and stirred to be dissolved; then re-steamed N,N-dimethylformamide is added, and nitrogen is introduced for deoxygenation; reactants aryl bromide and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, catalyst palladium acetate, ligand tri-o-tolylphosphine and additive tetrabutylammonium bromide are added sequentially, nitrogen is introduced for deoxygenation, temperature is increased to 100 DEG C, and stirring is performed untila reaction is finished; diarylethene with yield as high as 90% or higher is obtained finally through a post-processing procedure. With adoption of the synthetic method of diarylethene, yield is high,ethylene gas and a pressure container not easy to operate are not needed, and the synthetic method can be widely applied to industrial production and has better market application prospect.
- -
-
Paragraph 0049-0051
(2020/09/09)
-
- Synthetic method A-D-A configuration organic conjugated micromolecule
-
The invention provides a synthesis method of A-D-A conjugated small molecules. The method comprises the following steps: (1) by using 2-formylthiophene as a raw material and using zinc powder and titanium tetrachloride as catalysts, preparing a compound (I); (2) activating the site 2 of the compound (I) by using n-butyllithium, so as to form a lithium salt intermediate; then, adding 1-bromooctane to prepare a compound (II); (3) activating the site 2 of the compound (II) by using n-butyllithium, so as to form a lithium salt intermediate; then, adding trimethyltin chloride to prepare a compound (III); (4) performing reaction by 4,7-dibromo diazosulfide and the compound (III) to prepare a compound (IV); (5) respectively connecting 2-octyl trans-terthienyl based on diazosulfide onto the two ends of R1, R2, R3 and R4 to synthesize final products of S1, S2, S3 and S4.
- -
-
Paragraph 0026; 0033-0037
(2019/09/18)
-
- Stereodivergent Alkyne Reduction by using Water as the Hydrogen Source
-
A homogeneous Pd-catalyzed stereodivergent reduction of alkynes to Z and E alkenes by using H2O as the H2 source is presented. Mediated by a diboron reagent, the transfer hydrogenation has been accomplished to yield the desired geometrical isomer by rational ligand selection. The switchable stereoselectivity achieved using simple phosphine ligands is generally excellent. D2O has also been used as a D2 source for synthesizing the corresponding deuterated olefins. Supported by a gram-scale synthesis, the reaction can easily be scaled up making it an efficient way to prepare alkenes commercially as well. Mechanistic studies suggest formation of H?PdL2?OAc as the crucial step leading to the presence of two pathways involving H?Pd?B(OR)2 and molecular H2 as active intermediates.
- Rao, Santhosh,Prabhu, Kandikere Ramaiah
-
supporting information
p. 13954 - 13962
(2018/09/14)
-
- A process for the preparation of substituted cis
-
The invention belongs to the technical field of medicine and natural compound chemical intermediates and related chemistry, and relates to a preparation method of substituted cis-olefin. The method includes using alkyne and derivatives thereof as raw materials, a nanoporous gold catalyst as a catalyst, hydrogen gas as a hydrogen source and an organic alkali as a solvent, and performing selective hydrogenation to prepare cis-olefin, wherein hydrogen pressure is 0.1-20.0MPa; and molar concentration of alkyne and derivatives thereof in the solvent is 0.01-2mmol/mL. The catalyst is a nanoporous gold catalyst, the porous frame size is 5-50nm, and the molar ratio of alkyne and the derivatives thereof to the catalyst is 1:0.01-1:0.1. The method has the advantages of high product selectivity, and simple operation and post-treatment; and the catalyst is good in reproducibility, the catalytic effect is not significantly lowered after the catalyst is repeatedly used, which provides the possibility for industrialization.
- -
-
Paragraph 0039; 0040; 0041; 0042; 0043; 0044; 0045; 0046
(2017/07/01)
-
- Highly Selective Semihydrogenation of Alkynes to Alkenes by Using an Unsupported Nanoporous Palladium Catalyst: No Leaching of Palladium into the Reaction Mixture
-
We report the highly chemoselective and stereoselective semihydrogenation of alkynes to Z-internal and terminal alkenes by using unsupported nanoporous palladium (PdNPore) as a heterogeneous catalyst under mild reaction conditions (room temperature and 1 atm of H2). The semihydrogenation of various terminal/internal and aromatic/aliphatic alkynes afforded the corresponding alkenes in good chemical yields with high selectivities. PdNPore further showed high chemoselectivity toward terminal alkynes in the presence of internal alkynes, which has not yet been achieved using supported palladium nanoparticle catalysts. H-H heterolysis of H2 on the surface of PdNPore was strongly suggested by deuterium labeling experiments. No Pd leached from PdNPore during the reaction, and the catalyst was easily recovered and reused without a loss of activity.
- Lu, Ye,Feng, Xiujuan,Takale, Balaram S.,Yamamoto, Yoshinori,Zhang, Wei,Bao, Ming
-
p. 8296 - 8303
(2017/12/08)
-
- Unsupported Nanoporous Gold Catalyst for Chemoselective Hydrogenation Reactions under Low Pressure: Effect of Residual Silver on the Reaction
-
For the first time, H-H dissociation on an unsupported nanoporous gold (AuNPore) surface is reported for chemoselective hydrogenation of C=C, C=C, C=N, and C=O bonds under mild conditions (8 atm H2 pressure, 90 °C). Silver doping in AuNPore, which was inevitable for its preparation through a process of dealloying of Au-Ag alloy, exhibited a remarkable difference in catalytic activity between two catalysts, Au>99Ag1NPore and Au90Ag10NPore.The former was more active and the latter less active in H2 hydrogenation, while the reverse tendency was observed for O2 oxidation. This marked contrast between H2 reduction and O2 oxidation is discussed. Further, Au>99Ag1NPore showed a high chemoselectivity toward reduction of terminal alkynes in the presence of internal alkynes which was not achieved using supported gold nanoparticle catalysts and other previously known methods. Reductive amination, which has great significance in synthesis of amines due to its atom-economical nature, was also realized using Au>99Ag1NPore, and the Au>99Ag1NPore/H2 system showed a preference for the reduction of aldehydes in the presence of imines. In addition to this high chemoselectivity, easy recovery and high reusability of AuNPore make it a promising heterogeneous catalyst for hydrogenation reactions.
- Takale, Balaram S.,Feng, Xiujuan,Lu, Ye,Bao, Ming,Jin, Tienan,Minato, Taketoshi,Yamamoto, Yoshinori
-
supporting information
p. 10356 - 10364
(2016/08/31)
-
- Selective rhodium-catalyzed hydroformylation of alkynes to α,β-unsaturated aldehydes with a tetraphosphoramidite ligand
-
A tetraphosphoramidite ligand was successfully applied to a Rh-catalyzed hydroformylation of various symmetrical and unsymmetrical alkynes to afford corresponding α,β-unsaturated aldehyde products in good to excellent yields (up to 97% yield). Excellent chemo- and regioselectivities and high activities (up to 20 000 TON) were achieved. The corresponding α,β-unsaturated aldehyde products can be transformed into many useful and important organic molecules, such as indenamine derivatives and lukianol pyrroles. This great performance makes the hydroformylation of alkynes highly practical with great potential.
- Zhang, Zongpeng,Wang, Qian,Chen, Caiyou,Han, Zhengyu,Dong, Xiu-Qin,Zhang, Xumu
-
supporting information
p. 3290 - 3293
(2016/07/13)
-
- Evaporable organic semiconductive material and use thereof in an optoelectronic component
-
The invention relates to compounds of general formula IIIa and their use in optoelectronic components.
- -
-
Page/Page column 43
(2015/10/05)
-
- Rhodium-catalyzed hydroformylation of alkynes employing a self-assembling ligand system
-
Hydroformylation of alkynes is an underdeveloped atom-economic and redox-neutral method to prepare enals. Applying a new electron poor self-assembling ligand system provides the first general rhodium-catalyst for the chemo- and stereoselective hydroformylation of dialkyl- as well as diaryl-substituted alkynes to furnish enals in excellent chemo- and stereoselectivity.
- Agabekov, Vladislav,Seiche, Wolfgang,Breit, Bernhard
-
p. 2418 - 2422
(2013/07/11)
-
- A cyclobutene-1,2-bis(imidazolium) salt as preligand for palladium-catalyzed cross-coupling reactions: Properties and applications
-
Spectroscopic investigations and the results of calculations on the title bis-imidazolium salt, its mono-and bis-carbenes, and its interactions with palladium are presented. In addition, we report on the scope and limitations of metal-catalyzed cross-coupling reactions performed with the title bis-imidazolium salt. The salt proved to be an efficient ligand precursor in room-temperature Suzuki-Miyaura reactions, C-C couplings with sterically extremely hindered biaryls,selective thiophene arylations, and couplings with vinylic chlorides. Spectroscopic investigations and the results of calculations on the title bis-imidazolium salt, its mono-and bis-carbenes, and its interactions with palladium are presented. In addition, we report on the scope and limitations of metal-catalyzed cross-coupling reactions performed with the title bis-imidazolium salt. Copyright
- Rahimi, Alireza,Papai, Imre,Madarasz, Udam,Gjikaj, Mimoza,Namyslo, Jan C.,Schmidt, Andreas
-
experimental part
p. 754 - 763
(2012/03/12)
-
- Identification and quantification of defect structures in poly(2,5-thienylene vinylene) derivatives prepared via the dithiocarbamate precursor route by means of NMR spectroscopy on 13C-labeled polymers
-
During the past decades several synthetic routes toward the low band gap polymer poly(2,5-thienylene vinylene) (PTV) and derivatives have been studied. This study describes an extensive NMR characterization of 13C-labeled 3-octyl-PTV and its precursor polymer prepared via the dithiocarbamate route which is, since stable monomers are available, a promising route toward PTV derivatives. By introducing 13C-labeled vinylene carbons, we were able to characterize these polymers in a quantitative way, taking the end groups and structural polymerization defects, which disturb the conjugated system, into account. Several NMR techniques and the synthesis of model compounds were used to fully assign the proton and carbon chemical shifts. Moreover, the classically used thermal conversion of the precursor toward the conjugated polymer has been compared to a smoother, acid-induced elimination procedure.
- Dilien,Chambon,Cleij,Lutsen,Vanderzande,Adriaensens
-
experimental part
p. 4711 - 4720
(2012/05/20)
-
- Electronic structural dependence of the photophysical properties of fluorescent heteroditopic ligands - Implications in designing molecular fluorescent indicators
-
Two fluorescent heteroditopic ligands (2a and 2b) for zinc ion were synthesized and studied. The efficiencies of two photophysical processes, intramolecular charge transfer (ICT) and photoinduced electron transfer (PET), determine the magnitudes of emission bathochromic shift and enhancement, respectively, when a heteroditopic ligand forms mono- or dizinc complexes. The electron-rich 2b is characterized by a high degree of ICT in the excited state with little propensity for PET, which is manifested in a large bathochromic shift of emission upon Zn2+ coordination without enhancement in fluorescence quantum yield. The electron-poor 2a displays the opposite photophysical consequence where Zn2+ binding results in greatly enhanced emission without significant spectral shift. The electronic structural effects on the relative efficiencies of ICT and PET in 2a and 2b as well as the impact of Zn2+-coordination are probed using experimental and computational approaches. This study reveals that the delicate balance between various photophysical pathways (e.g. ICT and PET) engineered in a heteroditopic ligand is sensitively dependent on the electronic structure of the ligand, i.e. whether the fluorophore is electron-rich or poor, whether it possesses a donor-acceptor type of structure, and where the metal binding occurs.
- Younes, Ali H.,Zhang, Lu,Clark, Ronald J.,Davidson, Michael W.,Zhu, Lei
-
experimental part
p. 5431 - 5441
(2011/01/12)
-
- McMurry coupling of aryl aldehydes and imino pinacol coupling mediated by Ti(O-i-Pr)4/Me3SiCl/Mg reagent
-
Ti(O-i-Pr)4/Me3SiCl/Mg reagent mediated McMurry coupling of aryl aldehydes to biaryl olefins at near room temperature. This low valent titanium (LVT) reagent also mediated the coupling of aldimines to 1,2-diamines (imino pinacol coupling).
- Okamoto, Sentaro,He, Jing-Qian,Ohno, Chihaya,Oh-iwa, Yuhji,Kawaguchi, Yuhki
-
experimental part
p. 387 - 390
(2010/03/03)
-
- Thiazole-based semiconductor compound and organic thin film transistor using the same
-
Provided are an organic semiconductor compound using thiazole, and an organic thin film transistor having an organic semiconductor layer formed of the organic semiconductor compound using thiazole. The novel organic semiconductor compound including thiazole has liquid crystallinity and excellent thermal stability, and thus is provided to form an organic semiconductor layer in the organic thin film transistor. To this end, a silicon oxide layer is formed on a silicon substrate, and an organic semiconductor layer including thiazole is formed on the silicon oxide layer. In addition, source and drain electrodes are formed on both edge portions of the organic semiconductor layer. The organic thin film transistor using the organic semiconductor layer has an improved on/off ratio and excellent thermal stability. Also, a solution process can be applied in its manufacture.
- -
-
Page/Page column 5-6
(2009/06/27)
-
- New amidino-benzimidazolyl thiophenes: Synthesis and photochemical synthesis
-
The photochemical synthesis of amidino-benzimidazolyl thiophenes was discussed. The amidino-benzimidazolyl-substituted bis-1,2-(2-thienyl) ethenes and benzo[1,2-b:4,3-b′] dithiophenes were prepared by the condensation of amidino-substituted o-phenylene diamines with corresponding dialdehydes. The synthesized bis-cationic bis-amidino benzimidazolyl substituted diphenylfurans were found to inhibit HIV-1 infection.
- Starcevic, Kristina,Boykin, David W.,Karminski-Zamola, Grace
-
p. 218 - 222
(2007/10/03)
-
- Synthesis of some new bis-(p-fluorophenyl)amides of the thieno[3,2-b]thiophene, thieno[3,2-b]furan and 1,2-bis{5-[2-(2-thienyl)ethenyl] 2-thienyl}ethene series
-
Three new heterocyclic substituted dianilides, namely 3-chloro-5-[1-(p- fluorophenylcarbamoyl)-2-(2-thienyl)ethenyl]thieno-[3,2-b]thiophene-2-carboxy-p- fluoroanilide (8), 1,2-bis{5-[2-(p-fluorophenylcarbamoyl)-2-(2-thienyl)ethenyl]- 2-thienyl}ethene (13) and 6-chloro-2-{2-[3-chloro-2-(p-fluorophenyl-carbamoyl)- 5-thieno[3,2-b]thienyl]-2-ethoxycarbonylethenyl}thieno[3,2-b] furan-5-carboxy-p-fluoroanilide (20) were prepared by multistep synthesis. The prepared dianilides are of particular interest for their potential to serve as the planar heteroaromatic core of DNA intercalators or groove binders.
- Pavlicic, Davorka,Koruznjak, Jasna Dogan,Banic-Tomisic, Zrinka,Karminski-Zamola, Grace
-
p. 871 - 884
(2007/10/03)
-
- Selective synthesis of 1-aryl-2-ferrocenylethylene by cross-metathesis
-
Novel synthesis of π-conjugated molecules by cross-metathesis reaction of vinylferrocene with a series of vinylarenes was investigated with a molybdenum-based Schrock catalyst (CHCMe2Ph)Mo(N-2,6-i-Pr2C6H3)[OCMe(C F3)2]2. The cross-metathesis reactions occurred successfully and the cross-metathesis product, i.e., heterodimers, were readily obtained selectively, together with only small amounts of the corresponding self-dimers.
- Yasuda, Tomohiro,Abe, Jiro,Iyoda, Tomokazu,Kawai, Tadashi
-
p. 812 - 813
(2007/10/03)
-
- Thiaheterohelicenes 1. Synthesis of unsubstituted thia[5]-, [9]- and [13]heterohelicenes
-
The unsubstituted thiaheterohelicenes, 5,8-dithia[5]helicene, 1, 5,8,11,14-tetrathia[9]helicene, 2, and 5,8,11,14,17,20-hexathia[13]helicene, 3, have been prepared. The key reaction was the oxidative photolysis of 1,2-diaryl-substituted ethenes which were prepared by Wittig-Horner or McMurry reactions. Acta Chemica Scandinavica 1996.
- Larsen, Jan,Bechgaard, Klaus
-
-
- Synthesis of new sulfur heteroaromatics isoelectronic with dibenzo[g,p]chrysene by photocyclization of thienyl- and phenyl-substituted ethenes
-
A series of new sulfur heteroarenes, isoelectronic with dibenzo[g,p]chrysene, have been prepared by double photocyclization of the corresponding tetraaryl substituted ethenes. The first step proceeds efficiently in each case, and the corresponding intermediate sulfur heteroarenes, isoelectronic with phenanthrene, have been isolated. The second ring closure is only efficient when one of the participating aryl substituents is thienyl, which thus manifests a higher electron density on the carbon atom involved in the excited singlet state reaction. Most of the new compounds are of minimal solubility in common solvents and do not display improved electron donor properties otherwise commonly found among heteroaromatics.
- Fischer, Erik,Larsen, Jan,Christensen, Jorn B.,Fourmigue, Marc,Madsen, Hans G.,Harrit, Niels
-
p. 6997 - 7005
(2007/10/03)
-
- PREPARATION OF A SERIES OF OLIGOVINYLENES
-
Preparation of a series of oligovinylenes (3) is reported.Compounds containing an even number of thiophene rings were synthesised by the carbonyl coupling of thiphenecarbaldehydes with as low-valent titanium reagent and those carrying an odd number of thiophene rings by the copuling of thiophenecarbaldehydes with Wittig-Horner (Witrtig) reagents.Uv-vis spectral feature of these compounds is also reported.
- Nakayama, Juzo,Fujimori, Toru
-
p. 991 - 1002
(2007/10/02)
-
- THERMOLYSIS OF SODIUM SALTS OF TOSYLHYDRAZONES OF SOME HETEROCYCLIC ALDEHYDES IN THE PRESENCE OF SILVER CHROMATE: 1,3 NC MIGRATION OF TOSYL GROUP
-
The thermal decompositions of sodium salts of tosylhydrazones of furfural, thiophene-2-aldehyde, 1-methylpyrrole-2-aldehyde, and pyridine-2-aldehyde in the presence of silver chromate gave 2-furyl(p-toluenesulfonyl)methane, thiophene-2-(p-toluenesulfonyl)methane, 1-methylpyrrole-2-(p-toluenesulfonyl)methane, and pyridine-2-(p-toluenesulfonyl)methane, respectively, via 1,3 NC migration of tosyl group.The same type of reactions with sodium salts of tosylhydrazones of thiophene-3-aldehyde, pyridine-3-aldehyde, and pyridine-4-aldehyde also afforded the corresponding p-toluenesulfonylmethanes but the yields were slightly lower comparing to the above cases.
- Saito, Katsuhiro,Ishihara, Hiraku
-
p. 1891 - 1898
(2007/10/02)
-
- RHODIUM ION CATALYZED DECOMPOSITION OF ARYLDIAZOALKANES
-
Aryldiazomethanes are converted by rhodium(II)acetate and iodorhodium(III) tetraphenylporphyrin to cis- rather than trans-1,2-diarylethylenes.Secondary aryldiazoalkanes react with rhodium(II) acetate to give azines.
- Shankar, B.K. Ravi,Shechter, Harold
-
p. 2277 - 2280
(2007/10/02)
-
- The Heteroaromatic Cope Rearrangement of 1-Pyridyl-, 1-Furyl-, and 1-Thienyl-2-vinylcyclopropanes
-
The 1-pyridyl-2-vinylcyclopropanes 3a and 5a rearrange to the cycloheptapyridines 10a and b on heating in an aromatic solvent.The reaction may be considered as an aromatic Cope rearrangement to 9, followed by a rearomatization step.N-Methylation of the starting vinylcyclopropane lowers the necessary reaction temperature markedly.The primary products 19 and 20 of the Cope rearrangement of the 1-furyl- or 1-thienyl-2-vinylcyclopropanes 3, 5c, d are thermally stable under the reaction conditions.The rearomatization of 19 and 20 is catalyzed by electrophiles (H+, CH3I) and, to a lower extent, by bases (pyridine).On heating to about 200 deg C in an inert aromatic solvent, 19a undergoes Retro-Cope rearrangement to 3c, aromatization to 21 as well as rearrangement to the cyclopentene 23.In all cases, the (Z)-vinylcyclopropanes undergo the Cope rearrangement faster than their (E)-isomers.
- Maas, Gerhard,Hummel, Christine
-
p. 3679 - 3696
(2007/10/02)
-
