42498-40-8Relevant academic research and scientific papers
Insight into Regioselective Control in Aerobic Oxidative C-H/C-H Coupling for C3-Arylation of Benzothiophenes: Toward Structurally Nontraditional OLED Materials
Bin, Zhengyang,Liao, Xingrong,Liu, Jiahui,Shen, Boming,Shi, Yang,Yan, Lipeng,Yang, Feng,Yang, Ge,Yang, Yudong,You, Jingsong,Yu, Peiyuan
supporting information, (2021/12/14)
The installation of (benzo)thiophene-containing biaryls via coupling reactions has become a staple in designing photoelectric materials. Undeniably, C-H/C-H cross-coupling reactions between two (hetero)aromatics would be a shortcut toward these structural fragments. While more reliable cross-coupling technologies are well-established to provide C2-arylated (benzo)thiophenes, efficient methods that arylate the C3-position remain underdeveloped. Herein we provide insight into the factors that determine regioselectivity switching for these cross-coupling reactions. X-ray crystallographic analysis gives solid evidence for the key roles of triflate in regioselective dearomatization and acetate in base-assisted anti-β-deprotonated rearomatization. The first isolation and X-ray characterization of a medium-sized dearomatized cyclometalated adduct involving both substrates provide extra insight into aerobic oxidative Ar-H/Ar-H cross-coupling reactions. The mechanistic breakthrough incubates the first example, enabling C-H/C-H-type C3-arylation of benzothiophenes. Finally, this chemistry is used to design blue-emitting thermally activated delayed fluorescence (TADF) materials with a helicene conformation that exhibit a high maximum external quantum efficiency of 25.4% in OLED.
Weak base-promoted selective rearrangement of oxaziridines to amidesviavisible-light photoredox catalysis
Park, Jin,Park, Sehoon,Jang, Gwang Seok,Kim, Ran Hui,Jung, Jaehoon,Woo, Sang Kook
, p. 9995 - 9998 (2021/10/06)
The selective rearrangement of oxaziridines to amidesviaa single electron transfer (SET) pathway is unexplored. In this study, we present a weak base-promoted selective rearrangement of oxaziridines to amidesviavisible-light photoredox catalysis. The developed method shows excellent functional group tolerance with a broad substrate scope and good to excellent yields. Furthermore, control experiments and density functional theory (DFT) calculations are performed to gain insight into the reactivity and selectivity.
Organophotoredox-Mediated Amide Synthesis by Coupling Alcohol and Amine through Aerobic Oxidation of Alcohol
Samanta, Samya,Shah, Sk. Sheriff,Shee, Maniklal,Singh, Amit Kumar,Singh, N. D. Pradeep,Venkatesh, Yarra
, (2020/03/05)
The combination of an organic photocatalyst [4CzIPN (1,2,3,5-tetrakis(carbazol-9-yl)-4,6 dicyanobenzene) or 5MeOCzBN (2,3,4,5,6-pentakis(3,6-dimethoxy-9 H-carbazol-9-yl)benzonitrile)], quinuclidine, and tetra-n-butylammonium phosphate (hydrogen-bonding catalyst) was employed for amide bond formations. The hydrogen-bonded OH group activated the adjacent C?H bond of alcohols towards hydrogen atom transfer (HAT) by a radical species. The quinuclidinium radical cation, generated through single-electron oxidation of quinuclidine by the photocatalyst, employed to abstract a hydrogen atom from the α-C?H bond of alcohols selectively due to a polarity effect-produced α-hydroxyalkyl radical, which subsequently converted to the corresponding aldehyde under aerobic conditions. Then the coupling of the aldehyde and an amine formed a hemiaminal intermediate that upon photocatalytic oxidation produced the amide.
Ionic liquid catalyzed Ritter reaction/Pd-catalyzed directed Ortho-arylation; facile access to diverse libraries of biaryl-amides from Aryl-nitriles
Sutar, Suraj M.,Savanur, Hemantkumar M.,Kalkhambkar, Rajesh G.,Borosky, Gabriela L.,Aridoss, Gopalakrishnan,Laali, Kenneth K.
supporting information, (2020/10/30)
Diverse libraries of biaryl-amides bearing N-t-butyl and N-adamantyl groups were synthesized in two steps by the Ritter reaction of aryl-nitriles, using tBuOH and AdaOH as carbocation precursors, and employing [BMIM(SO3H)][OTf] (neat or with [B
Nickel-catalyzed aminocarbonylation of Aryl/Alkenyl/Allyl (pseudo)halides with isocyanides and H2O
Li, Qiao,Cai, Yun,Jin, Hongwei,Liu, Yunkui,Zhou, Bingwei
supporting information, (2020/11/27)
Herein described is a nickel-catalyzed aminocarbonylation of aryl/alkenyl/allyl (pseudo)halides with isocyanides, providing aryl/alkenyl/allyl amides in 41% to 92% yields. Functional groups such as F, Cl, OMe, and heteroaromatic rings are compatible in the reaction. A Ni(0)/Ni(II) catalytic cycle is proposed based on preliminary experiments and previous literature. The reaction features readily available nickel salt, broad functional group tolerance, and simple reaction conditions.
CoFe2O4?SiO2-NH-βCD-BF3 as a supramolecular nanocomposite: Synthesis, characterization and catalytic activity
Hamadi, Hosein,Zanjani, Zohreh,Yadollahi, Mahtab
, (2019/11/14)
This manuscript describes synthesis of BF3-functionlized β-cylcodextrine grafted magnetic CoFe2O4 nanaoparticles as a hybrid magnetic nano-composite (CoFe2O4?SiO2-NH-βCD-BF3). The CoFe2O4?SiO2-NH-βCD-BF3 was fabricated by grafting of 6-O-toluenesulfonyl cyclodextrin (6-Ts-βCD) to 3-aminopropyl triethoxysilane coated magnetic CoFe2O4?SiO2 nanoparticles followed by combination with BF3. The CoFe2O4?SiO2-NH-βCD-BF3was characterized by FT-IR, TGA, VSM and SEM techniques. The feasibility of using CoFe2O4?SiO2-NH-βCD-BF3 as a magnetically recoverable catalyst was confirmed in the modified-Ritter reaction. The result showed that this novel nano-composite could serve as an efficient nanoreactor bearing super-acidic sites formed by immobilized BF3 and reuse at least for 6 times without loss in activity.
Oxidative C?H/C?H Cross-Coupling Reactions between N-Acylanilines and Benzamides Enabled by a Cp*-Free RhCl3/TFA Catalytic System
Shi, Yang,Zhang, Luoqiang,Lan, Jingbo,Zhang, Min,Zhou, Fulin,Wei, Wenlong,You, Jingsong
supporting information, p. 9108 - 9112 (2018/07/25)
By making use of a dual-chelation-assisted strategy, a completely regiocontrolled oxidative C?H/C?H cross-coupling reaction between an N-acylaniline and a benzamide has been accomplished for the first time. This process constitutes a step-economic and highly efficient pathway to 2-amino-2′-carboxybiaryl scaffolds from readily available substrates. A Cp*-free RhCl3/TFA catalytic system was developed to replace the [Cp*RhCl2]2/AgSbF6 system generally used in oxidative C?H/C?H cross-coupling reactions between two (hetero)arenes (Cp=pentamethylcyclopentadienyl, TFA=trifluoroacetic acid). The RhCl3/TFA system avoids the use of the expensive Cp* ligand and AgSbF6. As an illustrative example, the procedure developed herein greatly streamlines the total synthesis of the naturally occurring benzo[c]phenanthridine alkaloid oxynitidine, which was accomplished in excellent overall yield.
Bu4NI-Catalyzed Oxygen-Centered Radical Addition between Acyl Peroxides and Isocyanides
Chen, Meng,Li, Yang,Tang, Hong,Ding, Hao,Wang, Kai,Yang, Lingen,Li, Cuiting,Gao, Meng,Lei, Aiwen
supporting information, p. 3147 - 3150 (2017/06/23)
A novel oxygen-centered radical addition between acyl peroxides and isocyanides has been developed. A diverse collection of valuable arylcarboxyamides were easily synthesized by this protocol. From the preliminary mechanistic study, the elimination of carbon dioxide affords the product via an intramolecular rearrangement.
Organic template-free synthesis of zeolite Y nanoparticle assemblies and their application in the catalysis of the Ritter reaction
Tang, Ting,Zhang, Lei,Dong, Hai,Fang, Zhongxue,Fu, Wenqian,Yu, Quanyong,Tang, Tiandi
, p. 7711 - 7717 (2017/02/05)
Zeolite Y nanoparticle assemblies (Y-NA) with a mesoporous structure were directly synthesized at 75?°C for 16 h without adding any organic templates. The changes in structure, morphology and textural parameters of the materials obtained after different crystallization times were investigated via powder X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N2-sorption. The results show that Y-NA had a micro-mesoporous structure composed of highly crystalline particle assemblies with sizes of 400-900 nm. The H-form Y-NA (HY-NA) is strongly acidic, and exhibits a good catalytic performance in the Ritter reaction, as compared with the H-form microporous zeolite Y and mesoporous zeolite ZSM-5.
Cp?CoIII-Catalyzed syn-Selective C-H Hydroarylation of Alkynes Using Benzamides: An Approach Toward Highly Conjugated Organic Frameworks
Bera, Sourav Sekhar,Debbarma, Suvankar,Ghosh, Avick Kumar,Chand, Santanu,Maji, Modhu Sudan
, p. 420 - 430 (2017/04/26)
Hydroarylation of internal alkynes by cost-effective CoIII-catalysis, directed by N-tert-butyl amides, is achieved to avail mono- or dihydroarylated amide products selectively in an atom and step economic way. Several important functional groups were tolerated under the reaction conditions, and syn-hydroarylation products were exclusively isolated. Notably, a 4-fold C-H hydroarylation provided a highly conjugated organic framework in one step. Kinetic study with extensive deuterium labeling experiments were performed to support the proposed mechanism.
