22788-49-4Relevant academic research and scientific papers
Three-Fold Scholl-Type Cycloheptatriene Ring Formation around a Tribenzotriquinacene Core: Toward Warped Graphenes
Ip, Ho-Wang,Ng, Chun-Fai,Chow, Hak-Fun,Kuck, Dietmar
, p. 13778 - 13781 (2016)
A nonplanar polycyclic aromatic compound 6 bearing a tribenzotriquinacene (TBTQ) core merged with an o,p,o,p,o,p-hexaphenylene belt was prepared and characterized by NMR spectroscopy and X-ray crystallography. The key synthesis step involves three Scholl-type cycloheptatriene ring formation steps of the 1,4,8-tris(3′,4′-dimethoxyphenyl)-TBTQ derivative 5. The bridging of each of the three TBTQ bays by 1,2-phenylene units in compound 6 gives rise to an unusual wizard hat shaped structure, which represents a promising key intermediate for the construction of nonplanar nanographene molecules bearing a TBTQ core.
Asymmetric Transfer Hydrogenation of o-Hydroxyphenyl Ketones: Utilizing Directing Effects That Optimize the Asymmetric Synthesis of Challenging Alcohols
Clarkson, Guy J.,Wills, Martin,Zheng, Ye
supporting information, (2020/05/05)
A systematic range of o-hydroxyphenyl ketones were reduced under asymmetric transfer hydrogenation conditions using the C3-tethered catalyst 2. Two directing effects, i.e., an o-hydroxyphenyl coupled to a bulky aromatic on the opposite side of the ketone substrate, combine in a matched manner to deliver reduction products with very high enantiomeric excess.
Bulky N-Heterocyclic-Carbene-Coordinated Palladium Catalysts for 1,2-Addition of Arylboron Compounds to Carbonyl Compounds
Okuda, Yuta,Nagaoka, Masahiro,Yamamoto, Tetsuya
, p. 6291 - 6300 (2020/11/30)
The synthesis of primary, secondary, and tertiary alcohols by the 1,2-addition of arylboronic acids or boronates to carbonyl compounds, including unactivated ketones, using novel bulky yet flexible N-heterocyclic carbene (NHC)-coordinated 2,6-di(pentan-3-yl)aniline (IPent)-based cyclometallated palladium complexes (CYPs) as catalysts is reported. The PhS-IPent-CYP-catalyzed reactions are efficient at low catalyst loadings (0.02–0.3 mol% Pd), and the exceptional catalytic activity for 1,2-addition is attributed to the steric bulk of the NHC ligand. These reactions can yield a wide range of functionalized benzylic alcohols that are difficult to synthesize by classical protocols using highly active organomagnesium or lithium reagents.
Diaryl hydroxylamines as pan or dual inhibitors of indoleamine 2,3-dioxygenase-1, indoleamine 2,3-dioxygenase-2 and tryptophan dioxygenase
Winters, Maria,DuHadaway, James B.,Pham, Khoa N.,Lewis-Ballester, Ariel,Badir, Shorouk,Wai, Jenny,Sheikh, Eesha,Yeh, Syun-Ru,Prendergast, George C.,Muller, Alexander J.,Malachowski, William P.
supporting information, p. 455 - 464 (2018/11/25)
Tryptophan (Trp) catabolizing enzymes play an important and complex role in the development of cancer. Significant evidence implicates them in a range of inflammatory and immunosuppressive activities. Whereas inhibitors of indoleamine 2,3-dioxygenase-1 (IDO1) have been reported and analyzed in the clinic, fewer inhibitors have been described for tryptophan dioxygenase (TDO) and indoleamine 2,3-dioxygenase-2 (IDO2) which also have been implicated more recently in cancer, inflammation and immune control. Consequently the development of dual or pan inhibitors of these Trp catabolizing enzymes may represent a therapeutically important area of research. This is the first report to describe the development of dual and pan inhibitors of IDO1, TDO and IDO2.
The cytochrome: C -cyclo[6]aramide complex as a supramolecular catalyst in methanol
Pan, Wang,Mao, Lijun,Shi, Mingsong,Fu, Yonghong,Jiang, Xiaomin,Feng, Wen,He, Youzhou,Xu, Dingguo,Yuan, Lihua
supporting information, p. 3857 - 3866 (2018/03/06)
A hydrogen-bonded macrocycle, cyclo[6]aramide, was found to form a supramolecular complex with cytochrome c, which enables the solubilization of the heme protein in methanol. The supramolecular complexation was evidenced by UV-vis, CD, and Raman spectroscopic techniques via structural characterization. Computational simulation based on the DFT method reveals the presence of strong hydrogen bonds formed between the lysine residues exposed on the protein surface and the oxygen atoms residing in the cavity of cyclo[6]aramide apart from cation-π interactions. The resulting cytochrome c-cyclo[6]aramide 1 exhibited higher activities than unmodified cytochrome c in the oxidation of benzhydrol to benzophenone with hydrogen peroxide at low temperatures. The enhanced activity with lowering temperature up to -40 °C indicates that the complex can act as a "cold-active" synzyme. The results achieved here demonstrate the potential of hydrogen-bonded macrocycles in supramolecular chemistry for catalytic reactions via ligand-protein interactions.
Aminotriazole Mn(I) Complexes as Effective Catalysts for Transfer Hydrogenation of Ketones
Martínez-Ferraté, Oriol,Werlé, Christophe,Franciò, Giancarlo,Leitner, Walter
, p. 4514 - 4518 (2018/10/20)
A catalytic system based on complexes comprising abundant and cheap manganese together with readily available aminotriazole ligands is reported. The new Mn(I) complexes are catalytically competent in transfer hydrogenation of ketones with 2-propanol as hydrogen source. The reaction proceeds under mild conditions at 80 °C for 20 h with 3 % of catalyst loading using either KOtBu or NaOH as base. Good to excellent yields were obtained for a wide substrate scope with broad functional group tolerance. The obtained results by varying the substitution pattern of the ligand are consistent with an out-sphere mechanism for the H-transfer.
Grignard Reagents on a Tab: Direct Magnesium Insertion under Flow Conditions
Huck, Lena,De La Hoz, Antonio,Díaz-Ortiz, Angel,Alcázar, Jesus
supporting information, p. 3747 - 3750 (2017/07/26)
An on-demand preparation of organomagnesium reagents is presented using a new flow protocol. The risks associated with the activation of magnesium are circumvented by a new on-column initiation procedure. Required amounts of solutions with a precise titration were obtained. Telescoped flow or batch reactions allow access to a diverse set of functional groups.
Coupling of aromatic aldehydes with aryl halides in the presence of nickel catalysts with diazabutadiene ligands
Asachenko,Valaeva,Kudakina,Uborsky,Izmer,Kononovich,Voskoboynikov
, p. 456 - 463 (2017/03/08)
Nickel catalysts with diazabutadiene ligands promote cross-coupling of benzaldehydes with aryl halides in the presence of zinc as reducing agent, which leads to the corresponding benzhydrols and benzophenones. The benzophenone percentage considerably increases when lithium chloride additive is used.
Newly synthesized furanoside-based NHC ligands for the arylation of aldehydes
Denizalti, Serpil,?etin Telli, Fatma,Yildiran, Selin,Salman, Azize Ye?im,?etinkaya, Bekir
, p. 689 - 697 (2016/11/09)
New furanoside-based NHC precursor salts (2) were synthesized using amino alcohols from the chloralose derivatives of glucose (a), galactose (b), and mannose (c). The novel compounds were fully characterized by 1H NMR, 13C NMR, and elemental analyses. The catalytic activities of these salts were tested in the arylation of aldehydes as catalysts that were generated in situ from [RhCl(COD)]2. In addition, 2a was converted to the rhodium complex 3a in order to compare the results obtained in situ. The newly synthesized compounds were very efficient in terms of yield; nevertheless they did not exhibit a chiral induction.
Exploring the Reactivity of α-Lithiated Aryl Benzyl Ethers: Inhibition of the [1,2]-Wittig Rearrangement and the Mechanistic Proposal Revisited
Velasco, Rocío,Silva López, Carlos,Nieto Faza, Olalla,Sanz, Roberto
, p. 15058 - 15068 (2016/10/11)
By carefully controlling the reaction temperature, treatment of aryl benzyl ethers with tBuLi selectively leads to α-lithiation, generating stable organolithiums that can be directly trapped with a variety of selected electrophiles, before they can undergo the expected [1,2]-Wittig rearrangement. This rearrangement has been deeply studied, both experimentally and computationally, with aryl α-lithiated benzyl ethers bearing different substituents at the aryl ring. The obtained results support the competence of a concerted anionic intramolecular addition/elimination sequence and a radical dissociation/recombination sequence for explaining the tendency of migration for aryl groups. The more favored rearrangements are found for substrates with electron-poor aryl groups that favor the anionic pathway.
