15861-24-2Relevant articles and documents
Visible light mediated selective oxidation of alcohols and oxidative dehydrogenation of N-heterocycles using scalable and reusable La-doped NiWO4nanoparticles
Abinaya, R.,Balasubramaniam, K. K.,Baskar, B.,Divya, P.,Mani Rahulan, K.,Rahman, Abdul,Sridhar, R.,Srinath, S.
, p. 5990 - 6007 (2021/08/24)
Visible light-mediated selective and efficient oxidation of various primary/secondary benzyl alcohols to aldehydes/ketones and oxidative dehydrogenation (ODH) of partially saturated heterocycles using a scalable and reusable heterogeneous photoredox catalyst in aqueous medium are described. A systematic study led to a selective synthesis of aldehydes under an argon atmosphere while the ODH of partially saturated heterocycles under an oxygen atmosphere resulted in very good to excellent yields. The methodology is atom economical and exhibits excellent tolerance towards various functional groups, and broad substrate scope. Furthermore, a one-pot procedure was developed for the sequential oxidation of benzyl alcohols and heteroaryl carbinols followed by the Pictet-Spengler cyclization and then aromatization to obtain the β-carbolines in high isolated yields. This methodology was found to be suitable for scale up and reusability. To the best of our knowledge, this is the first report on the oxidation of structurally diverse aryl carbinols and ODH of partially saturated N-heterocycles using a recyclable and heterogeneous photoredox catalyst under environmentally friendly conditions.
Recyclable and Reusable Pd(OAc)2/XPhos–SO3Na/PEG-400/H2O System for Cyanation of Aryl Chlorides with Potassium Ferrocyanide
Cai, Mingzhong,Huang, Bin,Liu, Rong,Xu, Caifeng
, (2021/12/03)
Pd(OAc)2/XPhos–SO3Na in a mixture of poly(ethylene glycol) (PEG-400) and water is shown to be a highly efficient catalyst for the cyanation of aryl chlorides with potassium ferrocyanide. The reaction proceeded smoothly at 100 or 120?oC with K2CO3 or KOAc as base, delivering a variety of aromatic nitriles in good to excellent yields. The isolation of the crude products is facilely performed by extraction with cyclohexane and more importantly, both expensive Pd(OAc)2 and XPhos–SO3Na in PEG-400/H2O system could be easily recycled and reused at least six times without any apparent loss of catalytic efficiency. Graphical Abstract: Palladium-catalyzed cyanation of aryl chlorides with potassium ferrocyanide leading to aryl nitriles by using Pd(OAc)2/XPhos–SO3Na/PEG-400/H2O as a highly efficient and recyclable catalytic system is described.[Figure not available: see fulltext.]
Design, Synthesis, and Biological Evaluation of Novel 3-Aminomethylindole Derivatives as Potential Multifunctional Anti-Inflammatory and Neurotrophic Agents
Wang, Wei-Wei,Liu, Ting,Lv, Yu-Meng,Zhang, Wu-Yang,Liu, Zhi-Gang,Gao, Jin-Ming,Li, Ding
, p. 1593 - 1605 (2021/05/31)
The development of multifunctional molecules that are able to simultaneously interact with several pathological components has been considered as a solution to treat the complex pathologies of neurodegenerative diseases. Herein, a series of aminomethylindole derivatives were synthesized, and evaluation of their application for antineuroinflammation and promoting neurite outgrowth was disclosed. Our initial screening showed that most of the compounds potently inhibited lipopolysaccharide (LPS)-stimulated production of NO in microglial cells and potentiated the action of NGF to promote neurite outgrowth of PC12 cells. Interestingly, with outstanding NO/TNF-α production inhibition and neurite outgrowth-promoting activities, compounds 8c and 8g were capable of rescuing cells after injury by H2O2. Their antineuroinflammatory effects were associated with the downregulation of the LPS-induced expression of the inflammatory mediators inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Western blotting and immunofluorescence assay results indicated that the mechanism of their antineuroinflammatory actions involved suppression of the MAPK/NF-κB signal pathways. Further studies revealed that another important reason for the high comprehensive antineuroinflammatory activity was the anti-COX-2 capabilities of the compounds. All these results suggest that the potential biochemical multifunctional profiles of the aminomethylindole derivatives provide a new sight for the treatment of neurodegenerative diseases.
Decarboxylation of indole-3-carboxylic acids under metal-free conditions
Chen, Xia,Zhou, Xiao-Yu
supporting information, p. 805 - 812 (2020/02/20)
Two reaction systems have been developed for the decarboxylation of indole-3-carboxylic acids. The decarboxylation can be achieved smoothly under K2CO3-catalyzed or acetonitrile-promoted basic conditions. It provided an efficient and simple method for the transformation of indole-3-carboxylic acids and the corresponding indoles were isolated with good to excellent yields. From the experimental facts, we put forward the possible reaction mechanism.
Reusable, homogeneous water soluble photoredox catalyzed oxidative dehydrogenation of N-heterocycles in a biphasic system: Application to the synthesis of biologically active natural products
Abinaya, R.,Baskar, B.,Mariappan, M.,Prasanth, Arun,Sridhar, R.,Srinath, S.
, p. 2575 - 2587 (2020/05/13)
Herein, a simple and efficient method for the oxidative dehydrogenation (ODH) of tetrahydro-β-carbolines, indolines and tetrahydro-(iso)quinolines is described using a reusable, homogeneous cobalt-phthalocyanine photoredox catalyst in a biphasic medium. A biphasic system offers an advantage of easy separation of the product and an efficient reusability of the homogeneous photoredox catalyst. Also, the current system significantly helps to overcome the solubility issue of the substrate and catalyst at room temperature. Its potential applications to organic transformations are demonstrated by the synthesis of various biologically active N-heterocycles such as indoles, (iso)quinolines and β-carbolines and natural products such as eudistomin U, norharmane, and harmane and precursors to perlolyrine and flazin. Without isolation and purification, the catalyst solution can be reused up to 5 times with almost comparable reactivity. Furthermore, the efficiency of the reaction was demonstrated on a gram scale. To the best of our knowledge, this is the first report on ODH reactions using a non noble, reusable and homogeneous cobalt photoredox catalyst under environmentally friendly conditions.
Novel commercial scale synthetic approach for 5-cyanoindole: A potential intermediate for vilazodone hydrochloride, an antidepressant drug
VENKATANARAYANA,NUCHU, RAVI,SHARATH BABU,GARREPALLI, GANGA SRAVANTHI,TANGALLAPALL, SUDHAKAR
, p. 2460 - 2462 (2020/10/22)
Present work describes the synthesis of 5-cyanoindole, a common intermediate used in various synthetic route of the antidepressant vilazodone hydrochloride. The protocol is both robust and commercially viable, utilizing readily available and low-cost materials and the isomers are environmental friendly than previously reported routes through its evading use of cyanide reagents and heavy metals.
Zn-catalyzed cyanation of aryl iodides
Zhao, Lulu,Dong, Yanan,Xia, Qiangqiang,Bai, Jianfei,Li, Yuehui
, p. 6471 - 6477 (2020/06/08)
We report the first example of zinc-catalyzed cyanation of aryl iodides with formamide as the cyanogen source. The transformation was promoted by the bisphosphine Nixantphos ligand. Under optimized conditions, a variety of electron-donating and electron-withdrawing aryl iodides were converted into nitrile products in good to excellent yields. This approach is an exceedingly simple and benign method for the synthesis of aryl nitriles and is likely to proceed via a dinuclear Zn-concerted catalysis.
Reductive cyanation of organic chlorides using CO2 and NH3 via Triphos–Ni(I) species
Dong, Yanan,Li, Yuehui,Yang, Peiju,Zhao, Shizhen
, (2020/08/19)
Cyano-containing compounds constitute important pharmaceuticals, agrochemicals and organic materials. Traditional cyanation methods often rely on the use of toxic metal cyanides which have serious disposal, storage and transportation issues. Therefore, there is an increasing need to develop general and efficient catalytic methods for cyanide-free production of nitriles. Here we report the reductive cyanation of organic chlorides using CO2/NH3 as the electrophilic CN source. The use of tridentate phosphine ligand Triphos allows for the nickel-catalyzed cyanation of a broad array of aryl and aliphatic chlorides to produce the desired nitrile products in good yields, and with excellent functional group tolerance. Cheap and bench-stable urea was also shown as suitable CN source, suggesting promising application potential. Mechanistic studies imply that Triphos-Ni(I) species are responsible for the reductive C-C coupling approach involving isocyanate intermediates. This method expands the application potential of reductive cyanation in the synthesis of functionalized nitrile compounds under cyanide-free conditions, which is valuable for safe synthesis of (isotope-labeled) drugs.
Nitrile Synthesis by Aerobic Oxidation of Primary Amines and in situ Generated Imines from Aldehydes and Ammonium Salt with Grubbs Catalyst
Utsumi, Tatsuki,Noda, Kenta,Kawauchi, Daichi,Ueda, Hirofumi,Tokuyama, Hidetoshi
supporting information, p. 3583 - 3588 (2020/08/05)
Herein, a Grubbs-catalyzed route for the synthesis of nitriles via the aerobic oxidation of primary amines is reported. This reaction accommodates a variety of substrates, including simple primary amines, sterically hindered β,β-disubstituted amines, allylamine, benzylamines, and α-amino esters. Reaction compatibility with various functionalities is also noted, particularly with alkenes, alkynes, halogens, esters, silyl ethers, and free hydroxyl groups. The nitriles were also synthesized via the oxidation of imines generated from aldehydes and NH4OAc in situ. (Figure presented.).
Nickel-Catalyzed Cyanation of Aryl Halides and Hydrocyanation of Alkynes via C-CN Bond Cleavage and Cyano Transfer
Chen, Hui,Sun, Shuhao,Liu, Yahu A.,Liao, Xuebin
, p. 1397 - 1405 (2020/02/04)
We report nickel-catalyzed cyanation and hydrocyanation methods to prepare aryl nitriles and vinyl nitriles from aryl halides and alkynes, respectively. Using inexpensive and nontoxic 4-cyanopyridine N-oxide as the cyano shuttle, the methods provide an efficient approach to prepare aryl cyanides and vinyl nitriles under mild and operationally simple reaction conditions with a broad range of functional group tolerances. In hydrocyanation of alkynes, the method demonstrated good regioselectivity, producing predominantly E- or Z-alkenyl nitriles in a controlled manner and exclusively Markovnikov vinyl nitriles when internal diaryl alkynes and terminal alkynes were applied as the substrates, respectively. The preliminary mechanistic investigation indicated that the C-CN bond cleavage process is promoted by oxidative addition to the nickel(I) complex in the cyanation of aryl halides, and further studies via a series of deuterium exchange experiments indicated that water serves as the hydrogen source for the hydrocyanation of alkynes.
