58518-78-8Relevant articles and documents
Photophysics of Perylene Diimide Dianions and Their Application in Photoredox Catalysis
Li, Han,Wenger, Oliver S.
supporting information, (2021/12/23)
The two-electron reduced forms of perylene diimides (PDIs) are luminescent closed-shell species whose photochemical properties seem underexplored. Our proof-of-concept study demonstrates that straightforward (single) excitation of PDI dianions with green
Influence of Steric Effect on the Pseudo-Multicomponent Synthesis of N-Aroylmethyl-4-Arylimidazoles
Elejalde-Cadena, Nerith Rocio,García-Olave, Mayra,Figueroa, David,Vidossich, Pietro,Miscione, Gian Pietro,Portilla, Jaime
, (2022/02/19)
A pseudo-three-component synthesis of N-aroylmethylimidazoles 3 with three new C–N bonds formed regioselectively under microwave conditions was developed. Products were obtained by reacting two equivalents of aroylmethyl bromide (ArCOCH2 Br, 1) with the appropriate amidine salt (RCN2 H3.HX, 2) and with K2 CO3 as a base in acetonitrile. The bicomponent reaction also occurred, giving the expected 4(5)-aryl-1H-imidazoles 4. Notably, the ratio of products 3 and 4 is governed by steric factors of the amidine 2 (i.e., R = H, CH3, Ph). Therefore, a computational study was carried out to understand the reaction course regarding product ratio (3/4), regioselectivity, and the steric effects of the amidine substituent group.
Cobalt-Catalyzed Reductive C-O Bond Cleavage of Lignin β-O-4 Ketone Models via in Situ Generation of the Cobalt-Boryl Species
Gao, Kecheng,Xu, Man,Cai, Cheng,Ding, Yanghao,Chen, Jianhui,Liu, Bosheng,Xia, Yuanzhi
supporting information, p. 6055 - 6060 (2020/08/12)
An efficient and mild method for reductive C-O bond cleavage of lignin β-O-4 ketone models was developed to afford the corresponding ketones and phenols with PDI-CoCl2 as the precatalyst and diboron reagent as the reductant. The synthetic utility of the methodology was demonstrated by depolymerization of a polymeric model and gram-scale transformation. Mechanistic studies suggested that this transformation involves steps of carbonyl insertion, 1,2-Brook type rearrangement, β-oxygen elimination, and rate-limiting regeneration of the catalytic active Co-B species.
Sulfur-mediated difunctionalization of internal and terminal alkynes for the synthesis of α-acetoxy ketones
Li, Pingfan,Zhang, Zhong
, (2020/02/13)
The sulfur-mediated difunctionalization of alkynes is reported to give α-acetoxy ketones in a one-pot operation under mild conditions with 19–92% yield. By using wet potassium acetate as both the aqueous base and nucleophilic reagent, both terminal alkynes and internal alkynes could be converted into the α-acetoxy ketone products.
Imidazolium-Based Ionic Network as a Robust Heterogeneous Catalyst in Synthesis of Phenacyl Derivatives
Kakesh,Sayyahi,Badri,Tahanpesar
, p. 1218 - 1220 (2019/07/16)
A new imidazolium-based poly(ionic liquid) has been synthesized and used as a robust heterogeneous catalyst for the preparation of phenacyl derivatives by an SN2 reaction of different phenacyl bromides with a broad range of nucleophiles. The products are obtained in high yields under mild conditions. The catalyst can be recycled efficiently.
PhI(OAc)2-promoted umpolung acetoxylation of enamides for the synthesis of α-acetoxy ketones
Chen, Ming,Zhang, Wei,Ren, Zhi-Hui,Gao, Wen-Yun,Wang, Yao-Yu,Guan, Zheng-Hui
, p. 761 - 768 (2017/06/05)
Umpolung is a fundamental concept in organic chemistry, which provides an alternative strategy for the synthesis of target compounds which were not easily accessible by conventional methods. Herein, a mild and efficient PhI(OAc)2-promoted umpolung acetoxylation reactions of enamides was developed for the synthesis of α-acetoxy ketones. The reaction tolerates a wide range of functional groups and affords α-acetoxy ketones in good to excellent yields. PhI(OAc)2 serves as a source of acetoxy in the reaction.
Fine Tuning the Redox Potentials of Carbazolic Porous Organic Frameworks for Visible-Light Photoredox Catalytic Degradation of Lignin β-O-4 Models
Luo, Jian,Zhang, Xiang,Lu, Jingzhi,Zhang, Jian
, p. 5062 - 5070 (2017/08/17)
We report a facile approach to fine tune the redox potentials of π-conjugated porous organic frameworks (POFs) by copolymerizing carbazolic electron donor (D) and electron acceptor (A) based comonomers at different ratios. The resulting carbazolic copolymers (CzCPs) exhibit a wide range of redox potentials that are comparable to common transition-metal complexes and are used in the stepwise photocatalytic degradation of lignin β-O-4 models. With the strongest oxidative capability, CzCP100 (D:A = 0:100) exhibits the highest efficiency for the oxidation of benzylic β-O-4 alcohols, while the highly reductive CzCP33 (D:A = 66:33) gives the highest yield for the reductive cleavage of β-O-4 ketones. CzCPs also exhibit excellent stability and recyclability and represent a class of promising heterogeneous photocatalysts for the production of fine chemicals from sustainable lignocellulosic biomass.
Integration of aqueous biphasic with magnetically recyclable systems: Polyethylene glycol-grafted Fe3O4 nanoparticles catalyzed phenacyl synthesis in water
Amini, Atefeh,Sayyahi, Soheil,Saghanezhad, Seyyed Jafar,Taheri, Narges
, p. 11 - 16 (2016/02/18)
The present work trends to define an efficient phenacyl catalytic synthesis method employing a new nano-magnetite-supported organocatalyst. Polyethylene glycol (PEG) was bonded successfully onto silica coated ferrite and the resultant nanoparticles (PEG@SiO2@Fe3O4) characterized by fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), thermal gravimetric analysis (TGA), vibrating sample magnetometry (VSM), energy dispersive X-ray analysis (EDAX) and X-ray diffraction (XRD) that exhibited a good catalytic activity in the reaction. The nanoparticles could be easily separated from the reaction mixture by an external magnet and reused in seven reaction cycles without significant loss of activity.
Novel and efficient transformation of enamides into α-acyloxy ketones via an acyl intramolecular migration process
Zhou, Xiaoqiang,Ma, Haojie,Cao, Jinhui,Liu, Xingxing,Huang, Guosheng
supporting information, p. 10070 - 10073 (2016/11/06)
Hydrogen peroxide and anhydride mediated transformation of enamides to afford substituted α-acyloxy ketones is described. This transition-metal-free cascade reaction has a broad substrate scope and high efficiency. The acyl intramolecular migration procedure successfully achieved this acyloxylation process under mild conditions and increased the atom efficiency.
Aerobic Oxidation of Olefins and Lignin Model Compounds Using Photogenerated Phthalimide-N-oxyl Radical
Luo, Jian,Zhang, Jian
, p. 9131 - 9137 (2016/10/17)
A metal-free protocol to generate phthalimide-N-oxyl (PINO) radicals from N-hydroxyphthalimide (NHPI) via a photoinduced proton-coupled electron transfer process is reported. Using donor-substituted aromatic ketones, such as 4,4′-bis(diphenylamino)benzophenone (DPA-BP), PINO radicals are efficiently produced and subsequently utilized to functionalize olefins to afford a new class of alkyl hydroperoxides. The DPA-BP/NHPI/O2 photocatalytic system exhibits high efficiency toward the aerobic oxidation of β-O-4 lignin models.
