- Highly efficient Au hollow nanosphere catalyzed chemo-selective oxidation of alcohols
-
Micelles of poly(styrene-b-2-vinyl pyridine-b-ethylene oxide) (PS-PVP-PEO) with core-shell-corona structures have been used as a scaffold for the fabrication of gold (Au) hollow nanospheres of particle size 26 ± 2 nm using HAuCl4 and NaBH4 as metal precursor and reducing agent, respectively. The PS core acts as a template for hollow void, the PVP shell serves as reaction sites for inorganic precursors, and PEO corona stabilizes the composite particles. Under acidic conditions, the PVP shell domain becomes positively charged pyridinum-species that electrostatically interacts with negatively charged AuCl4- ions. On reduction of these composite particles and subsequent solvent extraction leads to the formation of Au hollow nanospheres. Various analytical tools such as powder X-ray diffraction (XRD), transmission electron microscope (TEM), thermogravimetric analyses (TG/DTA), dynamic light scattering of (DLS) have been employed to characterize the polymeric micelles and hollow nanoparticles. The TEM and XRD studies confirmed the formation of highly crystalline Au hollow nanospheres. The Au hollow nanosphere/H2O2 system efficiently catalyzes the chemoselective oxidation of allylic-type unsaturated alcohols into aldehydes and ketones under mild liquid-phase conditions. The versatility of present catalytic system for the oxidation of other substrates like aliphatic-, acylic-, aromatic-, and heteroaromatic alcohols to their respective keto compounds has also been reported.
- Sasidharan, Manickam,Anandhakumar, Sundaramurthy,Bhanja, Piyali,Bhaumik, Asim
-
-
Read Online
- Kinetic Resolution of 1-Aryl- and 1-Heteroaryl Ethanols by Oxidation with Baker's Yeast
-
The kinetic resolution of racemic 1-aryl and 1-heteroaryl ethanols 1a-e via oxidation by Baker's yeast to give the R-enantiomer is reported.Key Words: Kinetic resolution, Oxidation, Baker's yeast, 1-Aryl ethanol, 1-Heteroaryl ethanol
- Fantin, Giancarlo,Fogagnolo, Marco,Medici, Alessandro,Pedrini, Paola,Poli, Silvia,Sinigaglia, Milena
-
-
Read Online
- Highly efficient dehydrogenation of secondary alcohols catalyzed by iridium-CNP complexes
-
A new highly practical method is presented for dehydrogenation of secondary alcohols to the corresponding ketones catalyzed by the iridium-CNP complexes. The reactions are compatible with substrates bearing diverse functional groups and proceed efficiently under mild conditions.
- Wang, Dawei,Zhao, Keyan,Yang, Shuyan,Ding, Yuqiang
-
-
Read Online
- Aerobic oxidation of alcohols at room temperature and atmospheric conditions catalyzed by reusable gold nanoclusters stabilized by the benzene rings of polystyrene derivatives
-
(Chemical Equation Presented) Lock up your gold: Polymer-incarcerated gold nanoclusters (PI Au) were synthesized by microencapsulation of gold nanoclusters and cross-linking using a copolymer based on polystyrene (see TEM image). The nanoclusters could be used to catalyze the aerobic oxidation of alcohols to aldehydes and ketones under atmospheric conditions at room temperature, and additionally could be reused with little loss of activity.
- Miyamura, Hiroyuki,Matsubara, Ryosuke,Miyazaki, Yoji,Kobayashi, Shu
-
-
Read Online
- Modular O-: Vs. N-coordination of pyridylidene amide ligands to iron determines activity in alcohol oxidation catalysis
-
A family of polydentate pyridine-substituted pyridylidene amide (PYA) complexes bound to iron(ii) was developed. The variation of the coordination set from NN-bidentate PYA to tridentate pincer-type pyPYA2 systems (pyPYA2 = 2,6-bis(PYA)pyridine) had a large influence on the binding mode to iron(ii), including a change from the N- to rare O-coordination of the PYA site and a concomitant shift of the predominant ligand resonance structure. These binding mode variations invoke changes in the reactivity of the complexes, which were probed in the peroxide-mediated oxidation of 1-phenylethanol to acetophenone. A comparison with uncomplexed FeCl2 indicated that bidentate NN coordination is unstable and presumably leads to the dissociation of FeCl2. In contrast, the tridentate ligand binding is robust. Remarkably, the tridentate PYA pincer coordination inhibits catalytic activity in the NNN binding mode, while the ONO coordination greatly enhances catalytic performance. Under optimized conditions, the bis-ligated ONO pincer iron complex [Fe(pyPYA2)2][2PF6] reaches full conversion within one hour (0.5 mol% catalyst loading) and under dilute conditions turnover numbers over 20?000 (0.005 mol% catalyst loading). This journal is
- Verhoeven, Dide G. A.,Albrecht, Martin
-
-
Read Online
- Acylation of Grignard reagents mediated by N-methylpyrrolidone: A remarkable selectivity for the synthesis of ketones
-
An efficient user-friendly method of acylation of Grignard reagents to selectively synthesize ketones is presented, which is assisted by simple amides such as NMP, or DMF. The present chemoselective method tolerates a variety of functional groups such as ketone, ester, nitrile and other functional groups.
- Gowda, Maravanhalli Sidde,Pande, Sushanth Sudhir,Ramakrishna, Ramesha Andagar,Prabhu, Kandikere Ramaiah
-
-
Read Online
- Studies on pyrazines; 38: Acylation of bromopyrazines and 2-bromopyridine via copper-cocatalytic stille reaction
-
Synthesis of acetylpyrazines 3 and propionylpyrazines 5 was achieved by copper-cocatalytic Stille reaction of bromopyrazines 1 with tributyl(1-ethoxyalkenyl)tin and then acidic hydrolysis. The optimal reaction conditions involve the combination of 15 molp
- Sato,Narita
-
-
Read Online
- New Organocatalyst scaffolds with high activity in promoting hydrazone and oxime formation at neutral pH
-
The discovery of two new classes of catalysts for hydrazone and oxime formation in water at neutral pH, namely 2-aminophenols and 2-(aminomethyl)benzimidazoles, is reported. Kinetics studies in aqueous solutions at pH 7.4 revealed rate enhancements up to 7-fold greater than with classic aniline catalysis. 2-(Aminomethyl)benzimidazoles were found to be effective catalysts with otherwise challenging aryl ketone substrates.
- Larsen, Dennis,Pittelkow, Michael,Karmakar, Saswata,Kool, Eric T.
-
-
Read Online
- Methoxy(2-pyridyl)ketene
-
The matrix photolysis of 3-methoxy-carbonyl-1,2,3-triazolopyridine was reported to yield methoxy(2-pyridyl)ketene. Photolysis of the triazolopyridines was found to be a less efficient method of producing the 2-pyridyl-ketenes. The results showed that a different ketene was formed by photolysis, but flash vacuum thermolysis (FVT) afforded the desired methoxy(2-pyridyl)ketene.
- Andersen, Heidi Gade,Bednarek, Pawel,Wentrup, Curt
-
-
Read Online
- Gold-platinum bimetallic clusters for aerobic oxidation of alcohols under ambient conditions
-
We have developed gold/platinum alloyed bimetallic cluster catalysts supported on a cross-linked polystyrene derivative, which present much higher activity and selectivity than single metal gold or platinum clusters for aerobic oxidation of alcohols under ambient conditions. The Royal Society of Chemistry.
- Miyamura, Hiroyuki,Matsubara, Ryosuke,Kobayashi, Shu
-
-
Read Online
- 4-CH3CONH-TEMPO/Peracetic Acid System for a Shortened Electron-Transfer-Cycle-Controlled Oxidation of Secondary Alcohols
-
We have developed a 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) derivative catalyzed oxidation of secondary alcohols with peracetic acid as the oxidant, which was generated from H2O2 and acetic acid catalyzed by strongly acidic resins. The oxidation of alcohols proceeded well through a shortened electron-transfer cycle under metal-free conditions, avoiding the use of any other electron-transfer mediators such as halides. In addition, we demonstrated that the present system exhibited excellent efficiency under mild conditions for the oxidation of aromatic, aliphatic, and allylic secondary alcohols. Shortcut to ketones: The 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-derivative-catalyzed oxidation of secondary alcohols employing peracetic acid generated from H2O2 and acetic acid with strongly acidic resins proceeds through a shortened electron-transfer cycle without halide additives. The system not only exhibits excellent efficiency at room temperature but also has a wide substrate scope.
- Zhang, Shufang,Miao, Chengxia,Xia, Chungu,Sun, Wei
-
-
Read Online
- Efficient aerobic oxidation of alcohols using a hydrotalcitesupported gold nanoparticle catalyst
-
Hydrotalcite-supported gold nanoparticles (Au/HT) were found to be a highly efficient heterogeneous catalyst for the aerobic oxidation of alcohols under mild reaction conditions (4O°C, in air). This catalyst system does not require any additives and is applicable to a wide range of alcohols, including less reactive cyclohexanol derivatives. This Au/HT catalyst could also function in the oxidation of 1-phenylethanol under neat conditions; the turnover number (TON) and turnover frequency (TOF) reached 200,000 and 8,300 h -1, respectively. These values are among the highest values compared to those of other reported catalyst systems at high conversion. Moreover, the Au/HT can be recovered by simple filtration and reused without any loss of its activity and selectivity.
- Mitsudome, Takato,Noujima, Akifumi,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
-
-
Read Online
- Silver nanoparticles immobilized onto poly(4-vinylpyridine)-functionalized magnetic nanoparticles: A robust magnetically recyclable catalyst for oxidant-free alcohol dehydrogenation
-
A heterogeneous and recyclable catalyst with a high loading of silver nanoparticles was synthesized via the silver nanoparticles being supported onto the surface of magnetic nanoparticles coated with poly(4-vinylpyridine). The synthesized catalyst was used in the dehydrogenation of alcohols to corresponding carbonyl compounds. A broad diversity of alcohols was converted into their corresponding carbonyl compounds in excellent yields. The catalyst was easily recovered by applying an external magnetic field and reused for seven reaction cycles without considerable loss of activity. The catalyst was fully characterized using various techniques.
- Bayat, Ahmad,Shakourian-Fard, Mehdi,Talebloo, Nazanin,Hashemi, Mohammed Mahmoodi
-
-
Read Online
- Boosting activity of molecular oxygen by pyridinium-based photocatalysts for metal-free alcohol oxidation
-
An eco-friendly and economical approach for the photocatalytic oxidation of organic inter-mediates by air under mild conditions is highly desirable in green and sustainable chemistry, where the photogeneration of active oxygen species plays a key role in improving conversion efficiency and selectivity. By using pyridinium derivatives as molecular mediators for electron transfer and energy transfer, the simultaneous activation of O2from air into superoxide radicals and singlet oxygen species can be achieved, and a photoinduced electron transfer catalytic system for the oxidation of alcohols has been developed. Thus, we have successfully simplified the complicated catalytic system into a single molecular catalyst without any additional noble metals and co-catalysts/additives. The current photocatalytic system shows high catalytic efficiency not only for aromatic alcohols but also for aliphatic alcohols that are generally difficult to undergo aerobic oxidation at room temperature under air atmosphere, representing an ideal photocatalytic platform for green and economical organic syntheses.
- Ma, Shuai,Cui, Jing-Wang,Rao, Cai-Hui,Jia, Meng-Ze,Chen, Yun-Rui,Zhang, Jie
-
-
Read Online
- Method for oxidative cracking of compound containing unsaturated double bonds
-
The invention relates to a method for oxidative cracking of a compound containing unsaturated double bonds. The method comprises the following steps: (A) providing a compound (I) containing unsaturated double bonds, a trifluoromethyl-containing reagent and a catalyst, wherein the catalyst is shown as a formula (II): M(O)mL1yL2z (II), M, L1, L2, m, y, z, R1, R2 and R3 being defined in the specification; and (B) mixing the compound containing the unsaturated double bonds and the trifluoromethyl-containing reagent, and performing an oxidative cracking reaction on the compound containing the unsaturated double bonds in the presence of air or oxygen by using the catalyst to obtain a compound represented by formula (III),.
- -
-
Paragraph 0108-0114; 0149-0151; 0170-0172
(2021/07/09)
-
- METHOD FOR OXIDATIVE CLEAVAGE OF COMPOUNDS WITH UNSATURATED DOUBLE BOND
-
A method for oxidative cleavage of a compound with an unsaturated double bond is provided. The method comprises the following step: (A) providing a compound (I) with an unsaturated double bond, a reagent with trifluoromethyl, and a catalyst; wherein the catalyst is represented by the following formula (II): M(O)mL1yL2z (II); wherein, M, L1, L2, m, y, z, R1, R2 and R3 are defined in the specification; and (B) mixing the compound with an unsaturated double bond and the reagent with a trifluoromethyl to perform an oxidation of the compound with the unsaturated double bond by using the catalyst at air or an oxygen condition to get a compound presented as formula (III):
- -
-
Paragraph 0053-0056
(2021/03/19)
-
- METHOD FOR OXIDATIVE CLEAVAGE OF COMPOUNDS WITH UNSATURATED DOUBLE BOND
-
A method for oxidative cleavage of a compound with an unsaturated double bond is provided. The method includes the steps of: (A) providing a compound (I) with an unsaturated double bond, a trifluoromethyl-containing reagent, and a catalyst; wherein, the catalyst is represented by Formula (II): M(O)mL1yL2z??(II);wherein, M, L1, L2, m, y, z, R1, R2 and R3 are defined in the specification; and(B) mixing the compound with an unsaturated double bond and the trifluoromethyl-containing reagent to perform an oxidative cleavage of the compound with the unsaturated double bond by using the catalyst in air or under oxygen atmosphere condition to obtain a compound represented by Formula (III):
- -
-
Paragraph 0071
(2021/07/10)
-
- Selective electrochemical oxidation of aromatic hydrocarbons and preparation of mono/multi-carbonyl compounds
-
A selective electrochemical oxidation was developed under mild condition. Various mono-carbonyl and multi-carbonyl compounds can be prepared from different aromatic hydrocarbons with moderate to excellent yield and selectivity by virtue of this electrochemical oxidation. The produced carbonyl compounds can be further transformed into α-ketoamides, homoallylic alcohols and oximes in a one-pot reaction. In particular, a series of α-ketoamides were prepared in a one-pot continuous electrolysis. Mechanistic studies showed that 2,2,2-trifluoroethan-1-ol (TFE) can interact with catalyst species and generate the corresponding hydrogen-bonding complex to enhance the electrochemical oxidation performance. [Figure not available: see fulltext.]
- Li, Zhibin,Zhang, Yan,Li, Kuiliang,Zhou, Zhenghong,Zha, Zhenggen,Wang, Zhiyong
-
p. 2134 - 2141
(2021/09/29)
-
- Selective Electrochemical Oxygenation of Alkylarenes to Carbonyls
-
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.
- Li, Xue,Bai, Fang,Liu, Chaogan,Ma, Xiaowei,Gu, Chengzhi,Dai, Bin
-
supporting information
p. 7445 - 7449
(2021/10/02)
-
- Visible-light photocatalytic selective oxidation of C(sp3)-H bonds by anion-cation dual-metal-site nanoscale localized carbon nitride
-
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.
- 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)
-
- Dimensional Reduction of Eu-Based Metal-Organic Framework as Catalysts for Oxidation Catalysis of C(sp3)–H Bond
-
Developing new catalysts for highly selectivity and conversion of saturated C(sp3)–H bonds is of great significance. In order to obtain catalysts with high catalytic performance, six Eu-based MOFs with different structural characteristics were obtained by using europium ions and different organic acid ligands, namely Eu-1~Eu-6. Eu-1, Eu-2 and Eu-3 featured three-dimensional structures, while Eu-4 and Eu-5 featured two-dimensional structures. Differently, a one-dimensional chain structure of Eu-6 was obtained by changing the ligand. All the six MOFs were applied to the catalytic reaction of C(sp3)–H bond, and it was found that the catalytic effect was gradually enhanced with the decrease of dimension and the increase of the size of channels. As expected, Eu-6 showed the highest selectivity (~99%) and conversion (~99%). Moreover, catalytic cycling and stability tests showed Eu-6 can be a reliable catalyst.
- Yan, Jun,Yu, Wei-Dong,Zhang, Yin,Zhao, Cai-Feng
-
-
- The dehydrogenative oxidation of aryl methanols using an oxygen bridged [Cu-O-Se] bimetallic catalyst
-
Herein, we report a new protocol for the dehydrogenative oxidation of aryl methanols using the cheap and commercially available catalyst CuSeO3·2H2O. Oxygen-bridged [Cu-O-Se] bimetallic catalysts are not only less expensive than other catalysts used for the dehydrogenative oxidation of aryl alcohols, but they are also effective under mild conditions and at low concentrations. The title reaction proceeds with a variety of aromatic and heteroaromatic methanol examples, obtaining the corresponding carbonyls in high yields. This is the first example using an oxygen-bridged copper-based bimetallic catalyst [Cu-O-Se] for dehydrogenative benzylic oxidation. Computational DFT studies reveal simultaneous H-transfer and Cu-O bond breaking, with a transition-state barrier height of 29.3 kcal mol?1
- Choudhury, Prabhupada,Behera, Pradyota Kumar,Bisoyi, Tanmayee,Sahu, Santosh Kumar,Sahu, Rashmi Ranjan,Prusty, Smruti Ranjita,Stitgen, Abigail,Scanlon, Joseph,Kar, Manoranjan,Rout, Laxmidhar
-
supporting information
p. 5775 - 5779
(2021/04/12)
-
- Method for preparing carbonyl compound through oxidative cleavage of visible light excitation aqueous solution quantum dot catalytic olefin compound
-
The invention provides a method for preparing carbonyl compounds through oxidative cleavage of a visible light excitation aqueous solution quantum dot catalytic olefin compound. Belong to photocatalysis synthesis technical field. To the method, an aqueous solution quantum dot is used as a photocatalyst, and an aqueous solution quantum dot activated molecular oxygen catalytic oxidation aromatic alkene compound is excited by visible light to be cracked to prepare a carbonyl compound. Low-loading capacity is used, a simple aqueous solution quantum dot is used as a catalyst, the yield of the carbonyl compound is high, TON more than ten millions are obtained. The reaction conditions are mild, water serves as a main solvent for the reaction, and the carbonyl compound can be obtained by catalytic olefin compound oxidation cracking without addition of a cocatalyst or the like. The method is simple to operate, wide in substrate range and low in cost.
- -
-
Paragraph 0042
(2021/11/10)
-
- Selective oxidation of alkenes to carbonyls under mild conditions
-
Herein, a practical and sustainable method for the synthesis of aldehydes, ketones, and carboxylic acids from an inexpensive olefinic feedstock is described. This transformation features very sustainable and mild conditions and utilizes commercially available and inexpensive tetrahydrofuran as the additive, molecular oxygen as the sole oxidant and water as the solvent. A wide range of substituted alkenes were found to be compatible, providing the corresponding carbonyl compounds in moderate-to-good yields. The control experiments demonstrated that a radical mechanism is responsible for the oxidation reaction.
- Huo, Jie,Xiong, Daokai,Xu, Jun,Yue, Xiaoguang,Zhang, Pengfei,Zhang, Yilan
-
supporting information
p. 5549 - 5555
(2021/08/16)
-
- Decatungstate-mediated solar photooxidative cleavage of CC bonds using air as an oxidant in water
-
With the increasing attention for green chemistry and sustainable development, there has been much interest in searching for greener methods and sources in organic synthesis. However, toxic additives or solvents are inevitably involved in most organic transformations. Herein, we first report the combination of direct utilization of solar energy, air as the oxidant and water as the solvent for the selective cleavage of CC double bonds in aryl olefins. Various α-methyl styrenes, diaryl alkenes as well as terminal styrenes are well tolerated in this green and sustainable strategy and furnished the desired carbonyl products in satisfactory yields. Like heterogeneous catalysis, this homogeneous catalytic system could also be reused and it retains good activity even after repeating three times. Mechanism investigations indicated that both O2- and 1O2 were involved in the reaction. Based on these results, two possible mechanisms, including the electron transfer pathway and the energy transfer pathway, were proposed.
- Du, Dongdong,Luo, Junfei,Shi, Sanshan,Xie, Pan,Xue, Cheng
-
p. 5936 - 5943
(2021/08/23)
-
- Photo-induced oxidative cleavage of C-C double bonds for the synthesis of biaryl methanoneviaCeCl3catalysis
-
A Ce-catalyzed strategy is developed to produce biaryl methanonesviaphotooxidative cleavage of C-C double bonds at room temperature. This reaction is performed under air and demonstrates high activity as well as functional group tolerance. A synergistic Ce/ROH catalytic mechanism is also proposed based on the experimental observations. This protocol should be the first successful Ce-catalyzed photooxidation reaction of olefins with air as the oxidant, which would provide inspiration for the development of novel Ce-catalyzed photochemical synthesis processes.
- Xie, Pan,Xue, Cheng,Du, Dongdong,Shi, SanShan
-
supporting information
p. 6781 - 6785
(2021/08/20)
-
- Visible-Light-Driven Oxidative Cleavage of Alkenes Using Water-Soluble CdSe Quantum Dots
-
The oxidative cleavage of C=C bonds is an important chemical reaction, which is a popular reaction in the photocatalytic field. However, high catalyst-loading and low turnover number (TON) are general shortcomings in reported visible-light-driven reactions. Herein, the direct oxidative cleavage of C=C bonds through water-soluble CdSe quantum dots (QDs) is described under visible-light irradiation at room temperature with high TON (up to 3.7×104). Under the same conditions, water-soluble CdSe QDs could also oxidize sulfides to sulfoxides with 51–84 % yields and TONs up to 3.4×104. The key features of this photocatalytic protocol include high TONs, wide substrates scope, low catalyst loadings, simple and mild reaction conditions, and molecular O2 as the oxidant.
- Li, Jianing,Zhao, Jingnan,Ma, Cunfei,Yu, Zongyi,Zhu, Hongfei,Yun, Lei,Meng, Qingwei
-
p. 4985 - 4992
(2021/10/16)
-
- Hydration of Alkynes to Ketones with an Efficient and Practical Polyoxomolybdate-based Cobalt Catalyst
-
Hydration of alkynes to ketones is one of the most atom economical and universal methods for the synthesis of carbonyl compounds. However, the basic reaction usually requires organic ligand catalysts or harsh reaction conditions to insert oxygen into the C≡C bond. Here, we report an inorganic ligand supported cobalt (III) catalyst, (NH4)3[CoMo6O18(OH)6], which is supported by a central cobalt (III) mononucleus and a ring-shaped pure inorganic ligand composed of six MoVIO6 octahedrons to avoid the disadvantages of expensive and unrecyclable organic ligand catalysts or noble metal catalysts. Under mild conditions, the cobalt (III) catalyst can be used for the hydration of alkynes to ketones. The catalyst is non-toxic, green, and environment friendly. The catalyst can be recycled at least six times with high activity. According to control experiments, a reasonable mechanism is provided.
- Xie, Ya,Wang, Jingjing,Wang, Yunyun,Han, Sheng,Yu, Han
-
p. 4985 - 4989
(2021/10/12)
-
- Overcoming Electron-Withdrawing and Product-Inhibition Effects by Organocatalytic Aerobic Oxidation of Alkylpyridines and Related Alkylheteroarenes to Ketones
-
An organocatalyzed aerobic benzylic C-H oxidation of alkyl and aryl heterocycles has been developed. This transition metal-free method is able to overcome the electron-withdrawing effect as well as product-inhibition effects in heterobenzylic radical oxidation. A variety of ketones bearing N-heterocyclic groups could be prepared under relatively mild conditions with moderate to high yields.
- Wang, Hua,Liu, Jie,Qu, Jian-Ping,Kang, Yan-Biao
-
p. 3942 - 3948
(2020/03/23)
-
- Selective Oxidation of Benzylic C-H Bonds Catalyzed by Cu(II)/{PMo12}
-
Precise catalytic regulation of carbon radical generation by a highly active oxygen radical to abstract the H atom in a C-H bond is an effective method for the selective activation of C-H synthetic chemistry. Herein, we report a facile catalyst system with commercially available copper(II)/{PMo12} to form a tert-butanol radical intermediate for the selective oxidation of benzylic C-H bonds. The reaction shows a broad range of substrates (benzyl methylene, benzyl alcohols) with good functional group tolerance and chemical selectivity. The corresponding carbonyl compounds were synthesized with good yields under mild conditions. DFT calculations and experimental analysis further demonstrated a reasonable carbon radical mechanism for this type of organic transformation reaction.
- Li, Peihe,Wang, Yingying,Wang, Xia,Wang, Yin,Liu, Ying,Huang, Keke,Hu, Jing,Duan, Limei,Hu, Changwen,Liu, Jinghai
-
p. 3101 - 3109
(2020/03/23)
-
- A sodium trifluoromethanesulfinate-mediated photocatalytic strategy for aerobic oxidation of alcohols
-
A sodium trifluoromethanesulfinate-mediated photocatalytic strategy for the aerobic oxidation of alcohols has been developed for the first time, and the photoredox aerobic oxidation of secondary and primary alcohols provided the corresponding ketones and carboxylic acids, respectively, in high to excellent yields.
- Zhu, Xianjin,Liu, Can,Liu, Yong,Yang, Haijun,Fu, Hua
-
p. 12443 - 12446
(2020/10/30)
-
- Heterogeneous photocatalytic anaerobic oxidation of alcohols to ketones by Pt-mediated hole oxidation
-
We report a platinum nanocluster/graphitic carbon nitride (Pt/g-C3N4) composite solid catalyst with a photocatalytic anaerobic oxidation function for highly active and selective transformation of alcohols to ketones. The desirable products were successfully obtained in good to excellent yields from various functionalized alcohols at room temperature, including unactivated alcohols. Mechanistic studies indicated that the reaction could proceed through a Pt-mediated hole oxidation initiating an α-alcohol radical intermediate followed by a two-electron oxidation pathway. The merit of this strategy offers a general approach towards green and sustainable organic synthetic chemistry.
- Sun, Danhui,Li, Peihe,Wang, Xia,Wang, Yingying,Wang, Jinghui,Wang, Yin,Lu, Ye,Duan, Limei,Sarina, Sarina,Zhu, Huaiyong,Liu, Jinghai
-
supporting information
p. 11847 - 11850
(2020/10/13)
-
- Redox-driven deracemization of secondary alcohols by sequential ether/O2-mediated oxidation and Ru-catalyzed asymmetric reduction
-
The deracemization of benzylic alcohols has been achieved using a redox-driven one-pot two-step process. The racemic alcohols were oxidized by bis(methoxypropyl) ether and oxygen to give the ketone intermediates, followed by an asymmetric transfer hydrogenation with a chiral ruthenium catalyst. This compatible oxidation/reduction process gave the enantiomerically enriched alcohols with up to 95% ee values.
- Yang, Bing,Cui, Peng,Chen, Yongsheng,Liu, Qixing,Zhou, Haifeng
-
supporting information
(2020/10/14)
-
- 2-Bromoanthraquinone as a highly efficient photocatalyst for the oxidation ofsec-aromatic alcohols: experimental and DFT study
-
Anthraquinones are recognized as high efficiency photocatalysts which can perform various redox reactions in aqueous or organic phases. We have experimentally proven that 2-BrAQ can undergo hydrogen transfer with an alpha-aromatic alcohol under light conditions, thereby efficiently oxidizing the aromatic alcohol to the corresponding product. The yield of 1-phenethanol to acetophenone can reach more than 96%. In subsequent catalyst screening experiments, it was found that the electronegativity of the substituent at the 2 position of the anthraquinone ring and the acidity of the solvent affect the photocatalytic activity of anthraquinones. After using various aromatic alcohol substrates, 2-BrAQ showed good conversion and selectivity for most aromatic alcohols, but showed C-C bond cleavage and low selectivity with non-α-position aromatic alcohols. In order to explore the mechanism of the redox reaction of 2-BrAQ in acetonitrile solution, the corresponding free radical reaction pathway was proposed and verified by density functional theory (DFT). Focusing on calculations for 2-BrAQ during the reaction and the first-step hydrogen transfer reaction between the 2-BrAQ triplet molecule and the 1-phenylethanol molecule, we recognized the changes that occurred during the reaction and thus have a deeper understanding of the redox reaction of anthraquinone compounds in organic systems.
- Chen, Guanghui,Liao, Shengfu,Liu, Jianguo,Liu, Qiying,Ma, Longlong,Yan, Long
-
p. 37014 - 37022
(2020/10/27)
-
- Synthesis method of 2-acetylpyridine
-
The invention provides a synthesis method of 2-acetylpyridine. The synthesis method comprises the following steps: carrying out a condensation reaction on ethyl 2-picolinate and tert-butyl acetate under alkaline conditions to obtain tert-butyl 2-pyridylacetate, further carrying out hydrolysis in a sulfuric acid solution with a concentration of 20%, and carrying out deacidification to obtain 2-acetylpyridine. The preparation method has the beneficial effects that since a better leaving group, i.e., a tert-butyl group, is adopted, reaction yield is greatly improved, good effect is achieved, andhigh yield is achieved.
- -
-
Paragraph 0017; 0019; 0020; 0022; 0023; 0025
(2020/03/06)
-
- Rhodium-Catalyzed Pyridine N-Oxide Assisted Suzuki-Miyaura Coupling Reaction via C(O)-C Bond Activation
-
A rhodium-catalyzed Suzuki-Miyaura coupling reaction via C(O)-C bond activation to form 2-benzoylpyridine N-oxide derivatives is reported. Both the C(O)-C(sp2) and C(O)-C(sp3) bond could be activated during the reaction with yields up to 92%. The N-oxide moiety could be employed as a traceless directing group, leading to free pyridine ketones.
- Zhong, Jing,Long, Yang,Yan, Xufei,He, Shiyu,Ye, Runyou,Xiang, Haifeng,Zhou, Xiangge
-
supporting information
p. 9790 - 9794
(2019/12/24)
-
- Electrochemical benzylic oxidation of C-H bonds
-
Oxidized products have become increasingly valuable as building blocks for a wide variety of different processes and fine chemistry, especially in the benzylic position. We report herein a sustainable protocol for this transformation through C-H functionalization and is performed using electrochemistry as the main power source and tert-butyl hydroperoxide as the radical source for the C-H abstraction. The temperature conditions reported here do not increase above 50 °C and use an aqueous-based medium. A broad substrate scope is explored, along with bioactive molecules, to give comparable and increased product yields when compared to prior reported literature without the use of electrochemistry.
- Marko, Jason A.,Durgham, Anthony,Bretz, Stacey Lowery,Liu, Wei
-
supporting information
p. 937 - 940
(2019/01/23)
-
- Iron-catalyzed oxidative functionalization of C(sp3)-H bonds under bromide-synergized mild conditions
-
An efficient oxidation and functionalization of C-H bonds with an inorganic-ligand supported iron catalyst and hydrogen peroxide to prepare the corresponding ketones was achieved using the bromide ion as a promoter. Preliminary mechanistic investigations indicated that the bromide ion can bind to FeMo6 to form a supramolecular species (FeMo6·2Br), which can effectively catalyze the reaction.
- Yu, Han,Zhao, Qixin,Wei, Zheyu,Wu, Zhikang,Li, Qi,Han, Sheng,Wei, Yongge
-
supporting information
p. 7840 - 7843
(2019/07/12)
-
- Method for preparing ketone compound through ethylbenzene compound
-
The invention provides a method for preparing a ketone compound through an ethylbenzene compound, and belongs to the field of catalytic chemistry. According to the method, the ethylbenzene compound isadded into a mixed solvent of water and acetonitrile, and then mixed with an oxidizing agent, and then a catalytic oxidation reaction is conducted after copper acetate and phosphomolybdic acid are added to obtain the ketone compound. According to the method, in the preparing process, a Cu/POM green catalytic system is formed to serve as a catalyst, the preparing method is simplified, preparationof polyoxometallate catalysts is not needed, polyoxometalates and metal copper salt are used together to serve as a green catalytic system, the catalytic effect is excellent, the POMs can overcome thecatalysis bottleneck of the metal copper salt, and effective catalysis of a model reaction is achieved.
- -
-
Paragraph 0067-0069
(2019/10/22)
-
- Sonochemical Preparation of Dipicolinamide Mn-complexes and Their Application as Catalysts Towards Sono-synthesis of Ketones
-
A series of non-heme Mn-complexes has been synthesized by the sonication of manganese (II)chloride and bis-amides (condensation products of 2-picolinic acid and o-phenylenediamines). The Mn-complexes effectively promote the oxidation of unactivated aliphatic and benzylic C─H and N-bearing heterocycles substrates with low catalyst loading using eco-friendly hydrogen peroxide in the presence of acetic acid as additive under ultrasonic irradiation. Chromatographic studies revealed that the corresponding ketones are the only detectable products. Noteworthy, the presence of electron donors in the catalyst structure significantly increased the reaction yields. The substantial lowering of the oxidation reaction yields by adding ionol (2,6-di-tert-butyl-4-methylphenol) as a free radical trap suggesting a free radical reaction pathway.
- Arafa, Wael A. A.
-
p. 1403 - 1412
(2019/02/25)
-
- Highly efficient and practical aerobic oxidation of alcohols by inorganic-ligand supported copper catalysis
-
The oxidation of alcohols to aldehydes or ketones is a highly relevant conversion for the pharmaceutical and fine-chemical industries, and for biomass conversion, and is commonly performed using stoichiometric amounts of highly hazardous oxidants. The aerobic oxidation of alcohols with transition metal complex catalysts previously required complicated organic ligands and/or nitroxyl radicals as co-catalysts. Herein, we report an efficient and eco-friendly method to promote the aerobic oxidation of alcohols using an inorganic-ligand supported copper catalyst 1, (NH4)4[CuMo6O18(OH)6], with O2 (1 atm) as the sole oxidant. Catalyst 1 is synthesized directly from cheap and commonly available (NH4)6Mo7O24·4H2O and CuSO4, which consists of a pure inorganic framework built from a central CuII core supported by six MoVIO6 inorganic scaffolds. The copper catalyst 1 exhibits excellent selectivity and activity towards a wide range of substrates in the catalytic oxidation of alcohols, and can avoid the use of toxic oxidants, nitroxyl radicals, and potentially air/moisture sensitive and complicated organic ligands that are not commercially available. Owing to its robust inorganic framework, catalyst 1 shows good stability and reusability, and the catalytic oxidation of alcohols with catalyst 1 could be readily scaled up to gram scale with little loss of catalytic activity, demonstrating great potential of the inorganic-ligand supported Cu catalysts in catalytic chemical transformations.
- Wei, Zheyu,Ru, Shi,Zhao, Qixin,Yu, Han,Zhang, Gang,Wei, Yongge
-
supporting information
p. 4069 - 4075
(2019/08/07)
-
- A Simple, Mild and General Oxidation of Alcohols to Aldehydes or Ketones by SO2F2/K2CO3 Using DMSO as Solvent and Oxidant
-
A practical, general and mild oxidation of primary and secondary alcohols to carbonyl compounds proceeds in yields of up to 99% using SO2F2 as electrophile in DMSO as both the oxidant and the solvent at ambient temperature. No moisture- and oxygen-free conditions are required. Stoichiometric amount of inexpensive K2CO3, which generates easy to separate by-products, is used as the base. Thus, 5-gram scale runs proceeded in nearly quantitative yields by a simple filtration as the work-up. The use of a polar solvent such as DMSO, which usually promotes competing Pummerer rearrangement, is also noteworthy. This protocol is compatible with a variety of common N-, O-, and S-functional groups on (hetero)arene, alkene and alkyne substrates (68 examples). The protocol was applied (99% yield) to a formal synthesis of the important cholesterol-lowering drug Rosuvastatin. (Figure presented.).
- Zha, Gao-Feng,Fang, Wan-Yin,Leng, Jing,Qin, Hua-Li
-
supporting information
p. 2262 - 2267
(2019/04/17)
-
- Method for synthesizing chiral alcohol through deracemization
-
The invention relates to a method for synthesizing chiral alcohol (formula I) through deracemization. The preparation method provided by the invention is one-pot asymmetric cascade reaction, and comprises the following steps: 1), with racemic alcohol (formula II) as a raw material and dipropylene glycol dimethyl ether as a solvent, reacting at 120 DEG C for 12 hours, and performing a dehydrogenation reaction to produce intermediate ketone (formula III); and 2), directly adding 2.5mol% of a chiral diamine metal ruthenium complex as a catalyst into a reaction system, with 5 equivalents of sodiumformate as a hydrogen source and a mixed solution of methanol and water as a solvent, reacting at 50 DEG C for 12 hours under the protection of nitrogen, and performing asymmetric transfer hydrogenation to obtain the chiral alcohol (formula I). The method has the advantages of environment-friendly synthesis such as a simple and mild reaction condition, step economy and atomic economy; and in addition, a substrate has a wide application range, the enantioselectivity is high, and the method has a broad application prospect in synthesis of chiral alcohol pharmaceutical intermediates and fine chemical raw materials.
- -
-
Paragraph 0068-0070
(2019/07/29)
-
- Preparation method of 2-acetylpyridine
-
The invention discloses a preparation method of 2-acetylpyridine. The preparation method comprises the following steps: (1) with 2-picolinic acid as a raw material, adding a first inert solvent and acatalyst, stirring and heating to 55-65 DEG C, dropwise adding a chlorinating agent, heating until a reflux reaction is occured, and performing reduced pressure distillation to obtain 2-pyridinecarbonyl chloride; (2) adding an inorganic salt catalyst, a second inert solvent, an alkaline substance and dialkyl malonate in a reaction bottle, sufficiently stirring, dropwise adding the 2-pyridinecarbonyl chloride, performing a heating reaction, neutralizing with hydrochloric acid, separating out an organic layer, washing with saturated sodium bicarbonate and a saturated salt solution in sequence, drying, and performing vacuum concentration to obtain 2-pyridinecarbonyl Di-tert-Butyl malonate; and (3) adding the 2-pyridinecarbonyl Di-tert-Butyl malonate in a mixed solution of water, organic acidand inorganic acid to perform a reflux reaction, regulating to be neutral with alkaline liquid, extracting with an organic solvent, and performing vacuum concentration to obtain 2-acetylpyridine. Thepreparation method has the advantages of being simple in raw materials, simple in operation, mild in condition, high in yield and small in pollution.
- -
-
Paragraph 0024-0027
(2019/04/04)
-
- SYNTHESIS OF HYPERVALENT IODINE REAGENTS WITH DIOXYGEN
-
Methods of synthesis of hypervalent iodine reagents and methods for oxidation of organic compounds are disclosed.
- -
-
Paragraph 0114-0117; 0130-0131
(2019/01/15)
-
- Efficient Palladium(0) supported on reduced graphene oxide for selective oxidation of olefins using graphene oxide as a ‘solid weak acid’
-
Selective oxidation of olefin derivatives to ketones has made innovative development over palladium(0) supported on reduced graphene oxide. Compared to traditional Wacker oxidation, the novel method offers an economical and environment-friendly option by using graphene oxide (GO) as a ‘solid weak acid’ instead of classical homogeneous catalysts like H2SO4 and CF3COOH. X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscopy images of Pd0/RGO showed that the nanoscaled Pd particles generated at the flake structure of reduced graphene oxide. Under optimized condition, up to 44 kinds of ketones with different structures can be prepared with excellent yields.
- Gao, Xi,Zhou, Jianhao,Peng, Xinhua
-
-
- Oxidation of Tertiary Aromatic Alcohols to Ketones in Water
-
A new rosin-based amphiphile enables the oxidation of tertiary aromatic alcohols in water under mild conditions. The oxidation process is mediated by β-scission of alkoxy radicals. Our catalyst system including the surfactant, catalysts, and water can be easily recycled within the same reaction vial. (Figure presented.).
- Chen, Dengfeng,Zhang, Yuchen,Pan, Xingyu,Wang, Fei,Huang, Shenlin
-
supporting information
p. 3607 - 3612
(2018/09/18)
-
- Continuous N-Hydroxyphthalimide (NHPI)-Mediated Electrochemical Aerobic Oxidation of Benzylic C?H Bonds
-
Electroorganic chemistry has emerged as an environmentally benign tool for synthetic chemists to achieve efficient transformations that are challenging with traditional reagent-based methods. Continuous flow chemistry brings pharmaceutical industry numerous advantages, but implementing electroorganic synthesis in flow is challenging, especially for electroorganic reactions with coupled electrode reactions and slow chemical reactions. We present a continuous electrolysis system engineered for N-hydroxyphthalimide (NHPI) mediated electrochemical aerobic oxidation of benzylic C?H bonds. First, a cation-exchange membrane prevents the crossover of the NHPI anion from anolyte to catholyte avoiding reductive decomposition of NHPI at the cathode, and enables the usage of a cost-effective reticulated vitreous carbon (RVC) cathode instead of a platinum electrode. Second, running the electrochemical flow cell with recycle streams accommodates the inherently slow kinetics of the chemical reaction without phthalimide-N-oxyl (PINO) radical self-decomposition at the anode, and allows the usage of gaseous oxygen as co-oxidant.
- Mo, Yiming,Jensen, Klavs F.
-
p. 10260 - 10265
(2018/07/29)
-
- Combined Iron/Hydroxytriazole Dual Catalytic System for Site Selective Oxidation Adjacent to Azaheterocycles
-
This report details a new method for site-selective methylene oxidation adjacent to azaheterocycles. A dual catalysis approach, utilizing both an iron Lewis acid and an organic hydroxylamine catalyst, proved highly effective. We demonstrate that this method provides complementary selectivity to other known catalytic approaches and represents an improvement over current heterocycle-selective reactions that rely on stoichiometric activation.
- Cooper, Julian C.,Luo, Chaosheng,Kameyama, Ryohei,Van Humbeck, Jeffrey F.
-
supporting information
p. 1243 - 1246
(2018/02/09)
-
- Highly practical and efficient preparation of aldehydes and ketones from aerobic oxidation of alcohols with an inorganic-ligand supported iodine catalyst
-
Herein, we divulge an efficient protocol for aerobic oxidation of alcohols with an inorganic-ligand supported iodine catalyst, (NH4)5[IMo6O24]. The catalyst system is compatible with a wide range of groups and exhibits high selectivity, and shows excellent stability and reusability, thus serving as a potentially greener alternative to the classical transformations.
- Zhang, Mengqi,Zhai, Yongyan,Ru, Shi,Zang, Dejin,Han, Sheng,Yu, Han,Wei, Yongge
-
supporting information
p. 10164 - 10167
(2018/09/13)
-
- Metal-Free catalyst for visible-light-induced oxidation of unactivated alcohols using Air/Oxygen as an oxidant
-
9-Fluorenone acts as a metal-free and additive-free photocatalyst for the selective oxidation of primary and secondary alcohols under visible light. With this photocatalyst, a plethora of alcohols such as aliphatic, heteroaromatic, aromatic, and alicyclic compounds has been converted to the corresponding carbonyl compounds using air/oxygen as an oxidant. In addition to these, several steroids have been oxidized to the corresponding carbonyl compounds. Detailed mechanistic studies have also been achieved to determine the role of the oxidant and the photocatalyst for this oxidation.
- Schilling, Waldemar,Riemer, Daniel,Zhang, Yu,Hatami, Nareh,Das, Shoubhik
-
p. 5425 - 5430
(2018/05/15)
-
- METHOD OF PRODUCING ORGANIC COMPOUND
-
A method of producing an organic compound, which contains a step of performing a deodorization step using a flow reaction in a flow passage to remove, from a reaction liquid, a malodorous material generated or remaining in a reaction step, wherein the organic compound is an industrially useful compound.
- -
-
Paragraph 0232; 0238; 0243; 0245; 0247; 0253; 0256-0259
(2018/09/16)
-
- Cp*CoIII-Catalyzed Efficient Dehydrogenation of Secondary Alcohols
-
A novel, well-defined molecular Cp*CoIII complex was isolated and structurally characterized for the first time. The efficiency of this cobalt catalyst was demonstrated in the alcohol dehydrogenation and dehydrative coupling of secondary alcohols under mild conditions into ketones and ethers, respectively.
- Gangwar, Manoj Kumar,Dahiya, Pardeep,Emayavaramban, Balakumar,Sundararaju, Basker
-
supporting information
p. 2445 - 2448
(2018/09/10)
-
- Oxidation Catalysis by an Aerobically Generated Dess–Martin Periodinane Analogue
-
Hypervalent iodine(V) reagents, such as Dess–Martin periodinane (DMP) and 2-iodoxybenzoic acid (IBX), are broadly useful oxidants in chemical synthesis. Development of strategies to generate these reagents from dioxygen (O2) would immediately enable use of O2 as a terminal oxidant in a broad array of substrate oxidation reactions. Recently we disclosed the aerobic synthesis of I(III) reagents by intercepting reactive oxidants generated during aldehyde autoxidation. In this work, aerobic oxidation of iodobenzenes is coupled with disproportionation of the initially generated I(III) compounds to generate I(V) reagents. The aerobically generated I(V) reagents exhibit substrate oxidation chemistry analogous to that of DMP. The developed aerobic generation of I(V) has enabled the first application of I(V) intermediates in aerobic oxidation catalysis.
- Maity, Asim,Hyun, Sung-Min,Wortman, Alan K.,Powers, David C.
-
supporting information
p. 7205 - 7209
(2018/05/29)
-
- An investigation into the role of 2,6-lutidine as an additive for the RuCl3-NaIO4 mediated oxidative cleavage of olefins to ketones
-
2,6-Lutidine has been identified as a beneficial additive for the oxidative cleavage of olefins to ketones by NaIO4 in the presence of catalytic RuCl3, improving the yield and shortening the reaction times. In the absence of 2,6-lutidine reactions stalled at the diol intermediate with incomplete conversion to the desired ketones. The reaction protocol described herein also avoids the use of harmful solvents such as CCl4 and DCE and is tolerant of a range of functional groups.
- Watson, David W.,Gill, Matthew,Kemmitt, Paul,Lamont, Scott G.,Popescu, Mihai V.,Simpson, Iain
-
supporting information
p. 4479 - 4482
(2018/11/23)
-
- Visible-Light-Driven Photocatalytic Oxidation of Organic Chlorides Using Air and an Inorganic-Ligand Supported Nickel-Catalyst Without Photosensitizers
-
Engineering photoredox-triggered chemical transformation via visible light has been an emerging area in organic synthesis. However, most of the well-established photocatalysts are based upon either transition metal complexes involved with noble metals and organic ligands or photosensitive organic dyes, the development of pure inorganic molecular photocatalysts that could provide better stability and durability is greatly retarded. Herein we discover that the Anderson polyoxometalate (POM) Na4[NiMo6O18(OH)6] (1), which consists of pure inorganic framework built from a central NiII core supported by six MoVIO6 inorganic scaffold/ligands, can be used as a powerful photocatalyst. Upon irradiation with visible light (>400 nm), the compound can catalyze, in high efficiency, a wide range of reactions, including the oxidative cross-coupling reaction of chlorides with amines, as well as oxidation of chlorides using molecular oxygen, affording various imines, aldehydes, and ketones, respectively in high selectivity and good yields. Owing to the robust inorganic framework, this catalyst exhibits excellent stability during the catalysis and reusability with little loss of the catalytic activity, thus providing an alternative without use of complicated organic ligands and expensive noble metal-based photosensitizers.
- Yu, Han,Wang, Jingjing,Zhai, Yongyan,Zhang, Mengqi,Ru, Shi,Han, Sheng,Wei, Yongge
-
p. 4274 - 4279
(2018/09/10)
-
- Selective aerobic oxidation of halides and amines with an inorganic-ligand supported zinc catalyst
-
A practical, efficient and environmentally benign catalytic protocol for the oxidative cross-coupling reaction of halides with amines, oxidative self-coupling of amines and oxidation of halides was developed with inorganic-ligand supported ZnPOM (NH4)4[ZnMo6O18(OH)6] using molecular oxygen. This method mainly utilizes an inorganic polymolybdate ligand to support the Zn2+ ion, avoiding the use of complicated organic ligands.
- Wang, Jingjing,Zhai, Yongyan,Wang, Ying,Yu, Han,Zhao, Wenshu,Wei, Yongge
-
supporting information
p. 13323 - 13327
(2018/10/15)
-
- Co/NHPI-mediated aerobic oxygenation of benzylic C-H bonds in pharmaceutically relevant molecules
-
A simple cobalt(ii)/N-hydroxyphthalimide catalyst system has been identified for selective conversion of benzylic methylene groups in pharmaceutically relevant (hetero)arenes to the corresponding (hetero)aryl ketones. The radical reaction pathway tolerates electronically diverse benzylic C-H bonds, contrasting recent oxygenation reactions that are initiated by deprotonation of a benzylic C-H bond. The reactions proceed under practical reaction conditions (1 M substrate in BuOAc or EtOAc solvent, 12 h, 90-100 °C), and they tolerate common heterocycles, such as pyridines and imidazoles. A cobalt-free, electrochemical, NHPI-catalyzed oxygenation method overcomes challenges encountered with chelating substrates that inhibit the chemical reaction. The utility of the aerobic oxidation method is showcased in the multigram synthesis of a key intermediate towards a drug candidate (AMG 579) under process-relevant reaction conditions.
- Hruszkewycz, Damian P.,Miles, Kelsey C.,Thiel,Stahl, Shannon S.
-
p. 1282 - 1287
(2017/02/10)
-
- TBHP-promoted direct oxidation reaction of benzylic Csp3-H bonds to ketones
-
A metal-free oxidation system employing tert-butyl hydroperoxide (TBHP) has been developed for selective oxidation of structurally diverse benzylic sp3 C-H bonds. This low-cost methodology allows for rapid generation of synthetically and biologically valued arylketones in good to excellent yields from readily available alkylarenes and diarylmethanes.
- Tan, Jiajing,Zheng, Tianyu,Yu, Yuqi,Xu, Kun
-
p. 15176 - 15180
(2017/03/17)
-
- Method for directly oxidizing benzyl-position C-H bond into ketone
-
The invention discloses a method for directly oxidizing a benzyl-position C-H bond into ketone, wherein aryl ethyl compounds are catalyzed and oxidized by nitrite ester; a synergistic catalytic system of free radical initiator and nitrite ester is adopted, and a catalytic system of non-metallic catalyst and oxygen is adopted, the oxidization of the C-H bond of a free radical-activated aryl side chain is simple in operation; after completing the reaction, petroleum ether/ethyl acetate at a volume ratio of (50-1):1 is used as an eluent; column chromatography separation is performed to obtain a target product. The catalytic system in the invention uses oxygen as an oxygen source and has high atomic economy; the invention is a non-metallic catalytic system and provides a novel method for avoid metal residues in synthetic drugs; for diethyl aromatic hydrocarbon, the method provided by the invention can be adopted to selectively oxidize diethyl aromatic hydrocarbon into monoketone and diketone; the method of the invention can be adopted to efficiently synthesize tranquillizer lenperone, so that a novel method for synthesizing lenperone is provided.
- -
-
Paragraph 0055-0057
(2017/08/29)
-
- Stereoselective amination of racemic sec-alcohols through sequential application of laccases and transaminases
-
A one-pot/two-step bienzymatic asymmetric amination of secondary alcohols is disclosed. The approach is based on a sequential strategy involving the use of a laccase/TEMPO catalytic system for the oxidation of alcohols into ketone intermediates, and their following transformation into optically enriched amines by using transaminases. Individual optimizations of the oxidation and biotransamination reactions have been carried out, studying later their applicability in a concurrent process. Therefore, 17 racemic (hetero) aromatic sec-alcohols with different substitutions in the aromatic ring have been converted into enantioenriched amines with good to excellent selectivities (90-99% ee) and conversion values (67-99%). The scalability of the process was also demonstrated when two different amine donors were used in the transamination step, such as isopropylamine and cis-2-buten-1,4-diamine. Satisfyingly, both sacrificial amine donors can shift the equilibrium toward the amine formation, leading to the corresponding isolated enantioenriched amines with good to excellent results.
- Martínez-Montero, Lía,Gotor, Vicente,Gotor-Fernández, Vicente,Lavandera, Iván
-
supporting information
p. 474 - 480
(2017/06/23)
-
