34541-73-6Relevant academic research and scientific papers
Efficient preparation method of symmetric diarylethene compound
-
Paragraph 0050-0052; 0056-0058, (2021/02/10)
The invention belongs to the technical field of fine chemicals and related chemistry, and provides an efficient preparation method of a symmetric diarylethene compound. The method comprises the following steps: with halomethyl-containing aromatic hydrocarbon and derivatives thereof as raw materials, conducting reacting at 100 DEG C for 12 hours in the presence of a catalyst, alkali, additives andan anhydrous organic solvent so as to obtain the corresponding diarylethene compound with symmetry. The method has the beneficial effects that no transition metal reaction exists, reaction conditionsare mild, operation is simple and convenient, the possibility of industrialization is realized, and the diarylethene compound is obtained at high yield; and the diarylethene compound synthesized by using the method can be further functionalized to obtain various compounds, and is applied to development and research of natural products, functional materials and fine chemicals.
Tuning the Selectivity of Palladium Catalysts for Hydroformylation and Semihydrogenation of Alkynes: Experimental and Mechanistic Studies
Beller, Matthias,Ge, Yao,Jackstell, Ralf,Jiao, Haijun,Liu, Jiawang,Wei, Duo,Wei, Zhihong,Yang, Ji
, p. 12167 - 12181 (2020/11/27)
Here, we describe a selective palladium catalyst system for chemodivergent functionalization of alkynes with syngas. In the presence of an advanced ligand L2 bearing 2-pyridyl substituent as a built-in base, either hydroformylation or semihydrogenation of diverse alkynes occurs with high chemo- and stereoselectivity under comparable conditions. Mechanistic studies, including density functional theory (DFT) calculations, kinetic analysis, and control experiments, revealed that the strength and concentration of acidic cocatalysts play a decisive role in controlling the chemoselectivity. DFT studies disclosed that ligand L2 not only promotes heterolytic activation of hydrogen similar to frustrated Lewis pair (FLP) systems in the hydrogenolysis step for hydroformylation but also suppresses CO coordination to promote semihydrogenation under strong acid conditions. This switchable selectivity provides a strategy to design new catalysts for desired products.
Oxidative Dephosphorylation of Benzylic Phosphonates with Dioxygen Generating Symmetrical trans-Stilbenes
Huang, Tianzeng,Chen, Tieqiao,Han, Li-Biao
, p. 2959 - 2965 (2018/03/09)
Under a dioxygen atmosphere, benzylphosphonates and related phosphoryl compounds can readily produce the corresponding trans-stilbenes in high yields with high selectivity upon treatment with bases. Various functional groups were tolerable under the reaction conditions.
Method for preparing trans-diphenylethylene compound
-
Paragraph 0070; 0071; 0080; 0081; 0107, (2017/09/01)
The invention relates to a preparation method of organic compounds and provides a method for preparing a trans-diphenylethylene compound. The method comprises adding a gem-dibromomethyl aromatic hydrocarbon compound, copper and polyamine into a reactor in the presence of a solvent, carrying out deoxidizing treatment, adding an oxygen-free water-free solvent into the reactor, carrying out a coupling reaction process to obtain C-C- double bonds, and carrying out separation and purification to obtain the trans-diphenylethylene compound. The method has mild synthesis conditions and has good reaction compatibility to different functional groups. The gem-dibromomethyl aromatic hydrocarbon compound as a raw material is easy to synthesize, may have different substituent groups and has a variable structure. The product obtained by coupling a raw material can be simply treated and has high purity. The asymmetric trans-diphenylethylene compound can be prepared from two different raw materials.
Chemoselective and Sequential Palladium-Catalyzed Couplings for the Generation of Stilbene Libraries via Immobilized Substrates
Traficante, Carla I.,Fagundez, Catherine,Serra, Gloria L.,Mata, Ernesto G.,Delpiccolo, Carina M. L.
supporting information, p. 225 - 229 (2016/06/01)
A versatile palladium-catalyzed tandem synthetic sequence to afford E-stilbenes libraries has been developed. Excellent regio- and stereocontrol have been achieved by means of the sequence of Hiyama and Heck cross-couplings. Undesirable homocoupling bypro
Variation of formal hydrogen-bonding networks within electronically delocalized π-conjugated oligopeptide nanostructures
Wall, Brian D.,Zhou, Yuecheng,Mei, Shao,Ardoa, Herdeline Ann M.,Ferguson, Andrew L.,Tovar, John D.
, p. 11375 - 11385 (2015/01/08)
This photophysical study characterizes the generality of intermolecular electronic interactions present within nanomaterials derived from self-assembling oligopeptides with embedded π-conjugated oligophenylenevinylene (OPV) subunits stilbene and distyrylbenzene that in principle present two distinct β-sheet motifs. Two different synthetic approaches led to oligopeptides that upon self-assembly are expected to self-assemble into multimeric aggregates stabilized by β-sheet-like secondary structures. The target molecules express either two C-termini linked to the central OPV core (symmetric peptides) or the more common N-termini to C-termini polarity typical of natural oligopeptides (nonsymmetric peptides). Both peptide secondary structures were shown to form extended 1-D peptide aggregates with intimate intermolecular π-electron interactions. Differences in length of the π-conjugated OPV segments resulted in differing extents of intermolecular interactions and the resulting photophysics. The peptides containing the shorter stilbene (OPV2) units showed little ground state interactions and resulted in excimeric emission, while the longer distyrylbenzene (OPV3) peptides had different ground state interactions between adjacent π-conjugated subunits resulting in either perturbed electronic properties arising from exciton coupling or excimer-like excited states. Molecular dynamics simulations of nascent aggregate formation predict peptide dimerization to be a spontaneous process, possessing thermodynamic driving potentials in the range 2-6 kcal/mol for the four molecules considered. Antiparallel stacking of the peptides containing an OPV3 subunit is thermodynamically favored over the parallel orientation, whereas both arrangements are equally favored for the peptides containing an OPV2 subunit. This study validates the generality of peptide-π-peptide self-assembly to provide electronically delocalized supramolecular structures and suggests flexibility in peptide sequence design as a way to tune the material properties of π-conjugated supramolecular polymers.
Organic halogenation chemistry as a vital tool for the construction of functional π-conjugated materials
Tovar, John D.
scheme or table, p. 2387 - 2391 (2011/09/21)
Recent and ongoing efforts by the Tovar research group to exploit organic halogenation chemistry for the development of complex organic electronic materials are described. Standard synthetic approaches involving free-radical and electrophilic reaction pathways are presented along with strategies that use ionizable protons or triazenes as masking groups for aromatic halides. Forward synthetic processes that highlight the extended chemistry that can be applied to these halogenated substrates to give complex π-conjugated molecules are also discussed. The examples presented are specific to work from the groups laboratories, but the halogenation procedures are sufficiently general to be suitable for use on many other conjugated frameworks. Georg Thieme Verlag Stuttgart New York.
Weakening C-O bonds: Ti(III), a new reagent for alcohol deoxygenation and carbonyl coupling olefination
Dieguez, Horacio R.,Lopez, Armando,Domingo, Victoriano,Arteaga, Jesus F.,Dobado, Jose A.,Herrador, M. Mar,Quilez Del Moral, Jose F.,Barrero, Alejandro F.
supporting information; experimental part, p. 254 - 259 (2010/03/25)
Investigations detailed herein, including density functional theory (DFT) calculations, demonstrate that the formation of either alkoxy- or hydroxy-Ti(III) complexes considerably decreases the energy of activation for C-O bond homolysis. As a consequence of this observation, we described two new synthetic applications of Nugent's reagent in organic chemistry. The first of these applications is an one-step methodology for deoxygenation-reduction of alcohols, including benzylic and allylic alcohols and 1,2-dihydroxy compounds. Additionally, we have also proved that Ti(III) is capable of mediating carbonyl coupling-olefination. In this sense, and despite the fact that for over 35 years it has been widely accepted that either Ti(II) or Ti(0) was the active species in the reductive process of the McMurry reaction, the mechanistic evidence presented proves the involvement of Ti(III) pinacolates in the deoxygenation step of the herein described Nugent's reagent-mediated McMurry olefination. This observation sheds some light on probably one of the mechanistically more complex transformations in organic chemistry. Finally, we have also proved that both of these processes can be performed catalytically in Cp 2TiCl2 by using trimethylsilyl chloride (TMSCl) as the final oxygen trap.
Stilbenes from Sulfur-Mediated Dehydrodimerization of Substituted Toluenes
Sickle, Dale E. Van
, p. 3263 - 3267 (2007/10/02)
When provision is made for removal of coproduct hydrogen sulfide, the reaction of sulfur with methyl p-toluate (MPT; 1) at 280 deg C leads to 70+percent yields of the product dimethyl trans-4,4'-stilbenedicarboxylate (DMSC, 2) if conversion of the MPT is restricted to ca 10percent.Diphenyl ether or excess MPT serves as the reaction solvent.Other products of the reaction include dimethyl 4,4'-bibenzyldicarboxylate (DBD, 3), 1,2,3-tris(4-carbomethoxyphenyl)propane (4), 1,2,3-tris(4-carbomethoxyphenyl)propene (5; mixture of E and Z isomers), and 2,3,4,5-tetrakis(4-carbomethoxyphenyl)thiophene (6).The products are consistent with the reversible formation of 4-carbomethoxybenzyl radicals from sulfur and MPT where removal of the hydrogen sulfide drives the reaction forward.
Surface Photochemistry: Exergonic and Endergonic Photocatalysed Reaction in the CdS-mediated cis-trans-Isomerization of cis-4-Substituted Stilbenes
Hasegawa, Tadashi,Mayo, Paul de
, p. 1534 - 1535 (2007/10/02)
The cis-stilbenes (1a-g) undergo photocatalysed cis-trans-isomerization on CdS; the Hammett plot for the reaction has a sharp break at ?(1+) = -0.19 ox1/2 = 1.47 V vs. standard calomel electrode> and is rationalized in terms of both exergonic and endergonic photocatalysed processes on the semiconductor with different rate-determining steps.
