99-91-2Relevant articles and documents
Catalytic oxidation of alcohols by a novel manganese Schiff base ligand derived from salicylaldehyd and l-Phenylalanine in ionic liquids
Rong, Meizhu,Wang, Juan,Shen, Yanping,Han, Jinyu
, p. 51 - 53 (2012)
A selective oxidation of alcohols to corresponding carbonyl compounds in ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate([bmim]BF4) was achieved by using a novel salicylaldehyd amino acid Schiff base manganese ligand. The catalytic s
Visible light-mediated, high-efficiency oxidation of benzyl to acetophenone catalyzed by fluorescein
Geng, Haoxing,Liu, Xin,Zhu, Qing
supporting information, (2021/12/20)
An environmentally friendly aerobic oxidation of benzyl C(sp3)-H bonds to ketones via selective oxidation catalysis was developed. Fluorescein is an efficient photocatalyst with excellent chemical selectivity. The reaction has a wide substrate scope, and a successful gram-scale experiment demonstrated its potential industrial utility.
Stepwise benzylic oxygenation via uranyl-photocatalysis
Hu, Deqing,Jiang, Xuefeng
supporting information, p. 124 - 129 (2022/01/19)
Stepwise oxygenation at the benzylic position (1°, 2°, 3°) of aromatic molecules was comprehensively established under ambient conditions via uranyl photocatalysis to produce carboxylic acids, ketones, and alcohols, respectively. The accuracy of the stepwise oxygenation was ensured by the tunability of catalytic activity in uranyl photocatalysis, which was adjusted by solvents and additives demonstrated through Stern–Volmer analysis. Hydrogen atom transfer between the benzylic position and the uranyl catalyst facilitated oxygenation, further confirmed by kinetic studies. Considerably improved efficiency of flow operation demonstrated the potential for industrial synthetic application.
Selective Activation of Unstrained C(O)-C Bond in Ketone Suzuki-Miyaura Coupling Reaction Enabled by Hydride-Transfer Strategy
Zhong, Jing,Zhou, Wuxin,Yan, Xufei,Xia, Ying,Xiang, Haifeng,Zhou, Xiangge
supporting information, p. 1372 - 1377 (2022/02/23)
A Rh(I)-catalyzed ketone Suzuki-Miyaura coupling reaction of benzylacetone with arylboronic acid is developed. Selective C(O)-C bond activation, which employs aminopyridine as a temporary directing group and ethyl vinyl ketone as a hydride acceptor, occurs on the alkyl chain containing a β-position hydrogen. A series of acetophenone products were obtained in yields up to 75%.
Efficient Aliphatic C-H Oxidation and C═C Epoxidation Catalyzed by Porous Organic Polymer-Supported Single-Site Manganese Catalysts
Wang, Bingyang,Lin, Jin,Sun, Qiangsheng,Xia, Chungu,Sun, Wei
, p. 10964 - 10973 (2021/09/08)
Bioinspired manganese complexes have emerged over recent decades as attractive catalysts for a number of selective oxidation reactions. However, these catalysts still suffer from oxidative degradation. In the present study, we prepared a series of porous Mn-N4 catalysts in which the catalytic units are embedded in the skeleton of porous organic polymers (POPs). These POP-based manganese catalysts demonstrated high reactivity in the oxidation of aliphatic C-H bonds and the asymmetric epoxidation of olefins. Furthermore, these catalysts could be readily recycled and reused due to their heterogeneous nature. Morphological characterization revealed that the Mn-N4 complex was individually distributed over a porous polymer network. Remarkably, the nature of the single-site catalyst prevented oxidative degradation during the reaction. The present work has thus developed a successful approach for bioinspired single-site manganese catalysts in which the oxidation reaction is confined to a specific channel in an enzyme-like mode.
Visible-light photocatalytic selective oxidation of C(sp3)-H bonds by anion-cation dual-metal-site nanoscale localized carbon nitride
Duan, Limei,Li, Peihe,Li, Wanfei,Liu, Jinghai,Liu, Ying,Liu, Zhifei,Lu, Ye,Sarina, Sarina,Wang, Jinghui,Wang, Yin,Wang, Yingying,Zhu, Huaiyong
, p. 4429 - 4438 (2021/07/12)
Selective oxidation of C(sp3)-H bonds to carbonyl groups by abstracting H with a photoinduced highly active oxygen radical is an effective method used to give high value products. Here, we report a heterogeneous photocatalytic alkanes C-H bonds oxidation method under the irradiation of visible light (λ= 425 nm) at ambient temperature using an anion-cation dual-metal-site modulated carbon nitride. The optimized cation (C) of Fe3+or Ni2+, with an anion (A) of phosphotungstate (PW123?) constitutes the nanoscale dual-metal-site (DMS). With a Fe-PW12dual-metal-site as a model (FePW), we demonstrate a A-C DMS nanoscale localized carbon nitride (A-C/g-C3N4) exhibiting a highly enhanced photocatalytic activity with a high product yield (86% conversion), selectivity (up to 99%), and a wide functional group tolerance (52 examples). The carbon nitride performs the roles of both the visible light response, and improves the selectivity for the oxidation of C(sp3)-H bonds to carbonyl groups, along with the function of A-C DMS in promoting product yield. Mechanistic studies indicate that this reaction follows a radical pathway catalyzed by a photogenerated electron and hole on A-C/g-C3N4that is mediated by thetBuO˙ andtBuOO˙ radicals. Notably, a 10 g scale reaction was successfully achieved for alkane photocatalytic oxidation to the corresponding product with a good yield (80% conversion), and high selectivity (95%) under natural sunlight at ambient temperature. In addition, this A-C/g-C3N4photocatalyst is highly robust and can be reused at least six times and the activity is maintained.
Ferric ion concentration-controlled aerobic photo-oxidation of benzylic C–H bond with high selectivity and conversion
Bu, Hongzhong,Gu, Jiefan,Li, Yufeng,Ma, Hongfei,Wan, Yuting,Wu, Zheng-Guang,Zhang, Weijian,Zhou, Ying'ao,Zhu, Hongjun
, (2021/07/16)
A Fe(III)-promoted highly selective photo-oxidation of benzylic C–H bond delivering relative carbonyl products is reported. By altering the concentration of ferric salt, methylarenes can be selectively oxidized under UV irradiation to furnish aromatic aldehydes or acids, respectively. By this protocol, the oxidation of ethylarenes provides the corresponding acetophenones. The reaction is inferred to involve divergent pathways in different concentrations of catalyst for the alternative selectivity between aldehydes and aicds. The reusable catalyst, high conversion and selectivity make this oxidation a green and economic protocol for the synthesis of aromatic carbonyl compounds.
Metal- And additive-free C-H oxygenation of alkylarenes by visible-light photoredox catalysis
García Manche?o, Olga,Kuhlmann, Jan H.,Pérez-Aguilar, María Carmen,Piekarski, Dariusz G.,Uygur, Mustafa
supporting information, p. 3392 - 3399 (2021/05/21)
A metal- and additive-free methodology for the highly selective, photocatalyzed C-H oxygenation of alkylarenes under air to the corresponding carbonyls is presented. The process is catalyzed by an imide-acridinium that forms an extremely strong photooxidant upon visible light irradiation, which is able to activate inert alkylarenes such as toluene. Hence, this is an easy to perform, sustainable and environmentally friendly oxidation that provides valuable carbonyls from abundant, readily available compounds.
HCl-Catalyzed Aerobic Oxidation of Alkylarenes to Carbonyls
Ding, Ling,Liu, Yuxiu,Niu, Kaikai,Shi, Xiaodi,Song, Hongjian,Wang, Qingmin
, (2021/12/13)
The construction of C?O bonds through C?H bond functionalization remains fundamentally challenging. Here, a practical chlorine radical-mediated aerobic oxidation of alkylarenes to carbonyls was developed. This protocol employed commercially available HCl as a hydrogen atom transfer (HAT) reagent and air as a sustainable oxidant. In addition, this process exhibited excellent functional group tolerance and a broad substrate scope without the requirement for external metal and oxidants. The mechanistic hypothesis was supported by radical trapping, 18O labeling, and control experiments.
Selective Electrochemical Oxygenation of Alkylarenes to Carbonyls
Li, Xue,Bai, Fang,Liu, Chaogan,Ma, Xiaowei,Gu, Chengzhi,Dai, Bin
supporting information, p. 7445 - 7449 (2021/10/02)
An efficient electrochemical method for benzylic C(sp3)-H bond oxidation has been developed. A variety of methylarenes, methylheteroarenes, and benzylic (hetero)methylenes could be converted into the desired aryl aldehydes and aryl ketones in moderate to excellent yields in an undivided cell, using O2 as the oxygen source and lutidinium perchlorate as an electrolyte. On the basis of cyclic voltammetry studies, 18O labeling experiments, and radical trapping experiments, a possible single-electron transfer mechanism has been proposed for the electrooxidation reaction.