2362-77-8Relevant academic research and scientific papers
Catalyst-free dynamic exchange of aromatic Schiff base bonds and its application to self-healing and remolding of crosslinked polymers
Lei, Zhou Qiao,Xie, Pu,Rong, Min Zhi,Zhang, Ming Qiu
, p. 19662 - 19668 (2015)
The present work reveals that catalyst-free dynamic reversible exchange of aromatic Schiff base bonds is enabled at room temperature. Attachment of aryl groups to both nitrogen and carbon atoms of carbon-nitrogen double bonds is a critical structural factor that contributes to the dynamic characteristics and complete reaction between aromatic aldehyde and aromatic amine. The exchange mechanism is studied by model compounds, and free radical intermediates are found to be involved in the non-equilibrium stage of the exchange reaction. By taking advantage of the dynamic equilibrium of aromatic Schiff base bonds, infusible and insoluble crosslinked polyacrylate is self-healed and reprocessed through rearrangement of macromolecular networks. The reprocessed polymer is still self-healable. Either the self-healing or reprocessing is completed in air without heating. Considering that Schiff base polymers have shown diverse properties and stimulus-response behaviors, activation of the dynamic exchange of the inherent Schiff base bonds would result in a series of novel functionalities. More interestingly, traditional crosslinked polymers might thus be provided with a facile way of being smarter.
One-pot imine synthesis from benzylic alcohols and nitrobenzene on CdS-sensitized TiO2 photocatalysts: Effects of the electric nature of the substituent and solvents on the photocatalytic activity
Nakai, Yuta,Azuma, Masashi,Muraoka, Masahiro,Kobayashi, Hisayoshi,Higashimoto, Shinya
, p. 203 - 208 (2017)
A new strategy for the one-pot synthesis of imines from several benzylic alcohols with such substituted groups as CF3, Cl, CH3, OCH3 and nitrobenzene were studied on the CdS-sensitized TiO2 (CdS-TiO2) photocatalyst under visible-light irradiation (λ > 420 nm) at room temperature. It was observed that the photocatalytic activities strongly depended on the electric nature of the substituted groups in the benzylic alcohols, following the Hammett rules. The photocatalytic activities can be explained by the photocurrent efficiency and a shift of the flatband potentials of the CdS photoelectrode depending on the degree of electron-donacity of the substituted groups. Moreover, the solvent effects on the yields of imines were also investigated in non-polar solvents (toluene, cyclohexane) and polar solvents (ethanol, acetonitrile). It was observed that the non-polar solvents caused higher photocatalytic activities for the synthesis of several imines than polar solvents due to the efficient condensation of photo-formed benzaldehyde and aniline.
Stereoselective synthesis of new β-lactams from the main functional group of indomethacin
Amiri, Mojgan,Islami, Mohammad Reza,Mortazavi, Zahra Fahimeh al-Sadat
, (2022/01/31)
New β-lactams were synthesized in moderate yields from indomethacin, which is currently used as a drug to relieve pain such as arthritis, muscle and bone damage. The reaction was carried out by [2 + 2] cycloaddition of the in situ formed indomethacinyl ke
Tandem imine formationviaauto-hydrogen transfer from alcohols to nitro compounds catalyzed by a nanomagnetically recyclable copper catalyst under solvent-free conditions
Derakhshan, Seyed Ruhollah,Hosseini Moghadam, Hadis,Sansano, José Miguel,Sobhani, Sara
, p. 19121 - 19127 (2021/06/03)
A direct imination reaction was developed by tandem reaction of alcohols and nitro compounds in the presence of Cu-isatin Schiff base-γ-Fe2O3as a nanomagnetically recyclable catalyst under solvent-free conditions. By this method, various imines were prepared in good to high yields from one-pot reaction of various alcohols (primary aromatic and aliphatic) and nitro compounds (aromatic and aliphatic)viaan auto-hydrogen transfer reaction. Use of an inexpensive and easily reusable catalyst, without requiring any additives or excess amounts of benzyl alcohol as the reaction solvent are the other advantages of this method. This catalytic system has the merits of cost effectiveness, environmental benignity, excellent recyclability and good reproducibility.
Au(I) Catalyzed Synthesis of Densely Substituted Pyrazolines and Dihydropyridines via Sequential Aza-Enyne Metathesis/6π-Electrocyclization
Sugimoto, Kenji,Kosuge, Shuto,Sugita, Takae,Miura, Yuka,Tsuge, Kiyoshi,Matsuya, Yuji
supporting information, p. 3981 - 3985 (2021/05/26)
A gold(I) autotandem catalysis protocol is reported for the de novo synthesis of densely substituted pyrazolines and dihydropyridines from the corresponding imine derivatives in a highly regioselective fashion via a one-pot aza-enyne metathesis/6π-electrocyclization sequence. The substituents on the nitrogen atom of the imine perfectly control the reaction pathways from the pivotal 1-azabutadiene intermediate; thus, carbazates were converted into pyrazolines via 6π-electrocyclization of α,β-unsaturated hydrazones, while aryl imines provided dihydropyridines via 6π-electrocyclization of 3-azahexatrienes.
Visible-Light-Induced Cycloaddition of α-Ketoacylsilanes with Imines: Facile Access to β-Lactams
Ye, Jian-Heng,Bellotti, Peter,Paulisch, Tiffany O.,Daniliuc, Constantin G.,Glorius, Frank
supporting information, p. 13671 - 13676 (2021/05/11)
We report the synthesis of β-lactams from α-ketoacylsilanes and imines, which proceeds via a formal [2+2] photochemical cycloaddition with in situ generation of siloxyketene. This mild and operationally simple reaction proceeds in an atom-economic fashion with broad substrate scope, including aldimines, ketimines, hydrazones, and fused nitrogen heterocycles, affording a variety of important β-lactams with satisfactory diastereoselectivities in most cases. This reaction also features good functional-group tolerance, facile scalability and product diversification. Experimental and computational studies suggest that α-ketoacylsilanes can serve as photochemical precursors by engaging in a 1,3 silicon shift to the distal carbonyl group.
Aza-peterson olefinations: Rapid synthesis of (E)-alkenes
Britten, Thomas K.,Basson, Ashley J.,Roberts, Dean D.,McLaughlin, Mark G.
, p. 3535 - 3544 (2021/06/03)
An aza-Peterson olefination methodology to access 1,3-dienes and stilbene derivatives from the corresponding allyl- or benzyltrimethylsilane is described. Silanes can be deprotonated using Schlosser's base and added to N -phenyl imines or ketones to directly give the desired products in high yields.
Rhodium catalyzed multicomponent dehydrogenative annulation: one-step construction of isoindole derivatives
Cheng, Biao,Lyu, Hairong,Quan, Yangjian,Xie, Zuowei
supporting information, p. 7930 - 7933 (2021/08/17)
A strategy for one-pot synthesis of isoindoles is describedviaa catalytic multicomponent dehydrogenative annulation of diarylimines, vinyl ketones and simple amines. In the presence of a rhodium catalyst and Cu oxidant, four C-H and two N-H bonds are activated along with the formation of one new C-C and two new C-N bonds, leading to a series of isoindole derivatives in good to very high isolated yields.
Photocatalytic one-pot multidirectional N-alkylation over Pt/D-TiO2/Ti3C2: Ti3C2-based short-range directional charge transmission
Jiang, Heyan,Sheng, Meilin,Li, Yue,Kong, Shuzhen,Bian, Fengxia
, (2021/05/17)
Visible-light-induced one-pot, multistep, and chemoselectivity adjustable reactions highlight the economical, sustainable, and green process. Herein, we report Pt nanoparticles dispersed on S and N co-doped titanium dioxide/titanium carbide (MXene) (3%Pt/
Redox-Neutral Imination of Alcohol with Azide: A Sustainable Alternative to the Staudinger/Aza-Wittig Reaction
Li, Huaifeng,Lupp, Daniel,Das, Pradip K.,Yang, Li,Gon?alves, Théo P.,Huang, Mei-Hui,El Hajoui, Marwa,Liang, Lan-Chang,Huang, Kuo-Wei
, p. 4071 - 4076 (2021/04/12)
The traditional Staudinger/aza-Wittig reaction represents one of the most powerful tools for imine formation. However, for this multistep procedure, the sacrificial phosphine has to be used, resulting in difficulties in the purification process and waste disposal at the same time. Here, we report a redox-neutral azide-alcohol imination methodology enabled by a base-metal nickel PN3 pincer catalyst. The one-step, waste-free, and high atom-economical features highlight its advantages further. Moreover, mechanistic insight suggests a non-metal-ligand cooperation pathway based on the observation of an intermediate and density functional theory calculations.
