93-08-3Relevant articles and documents
Fluorescence and phosphorescence of α- and β-isomers of boron Difluoride naphthaloylacetonates
Fedorenko, Elena V.,Mirochnik, Anatolii G.,Gerasimenko, Andrey V.,Beloliptsev, Anton Yu.,Puzyrkov, Zakhar N.,Svistunova, Irina V.,Sergeev, Aleksander A.
, (2021)
A comparative study of the luminescence properties of solutions and crystals of two isomers: boron difluoride 1-(1′-naphthyl)butanedionate-1,3 (α-NAcBF2) and 1-(2′-naphthyl)butanedionate-1,3 (β-NAcBF2) has been performed. An interrelation between the molecular and crystal structure of the studied complexes and their luminescence properties has been revealed. In the α-NAcBF2 molecule, the plane of the naphthyl group was turned by 34.26° relatively to the chelate cycle, while the β-NAcBF2 molecule was planar. The difference in the luminescence properties of the crystals of α-NAcBF2 (452 nm) and β-NAcBF2 (537 nm) was related to different abilities to form excimers. In β-NAcBF2 crystals, J-aggregates consisted of dimers of antiparallel molecules comprising excimer traps. For the crystals and solutions of α-NAcBF2 at 77 K, in addition to phosphorescence, the delayed fluorescence was observed. In case of β-NAcBF2, the delayed fluorescence was detected only for crystals, whereas the phosphorescence – for both crystals and solutions.
1-butyl-3-methylimidazolium cobalt tetracarbonyl [bmim][Co(CO)4]: A catalytically active organometallic ionic liquid
Brown,Dyson,Ellis,Welton
, p. 1862 - 1863 (2001)
An ambient temperature liquid transition metal carbonyl anion has been prepared in a metathesis reaction between [bmim]Cl ([bmim]+ = 1-butyl-3-methylimidazolium cation) and Na[Co(CO)4]; the ionic liquid catalyses the debromination of 2-bromoketones.
Enantioselective electrocatalytic oxidation of racemic sec-alcohols using a chiral 1-azaspiro[5.5]undecane-N-oxyl radical
Kashiwagi, Yoshitomo,Kurashima, Futoshi,Kikuchi, Chikara,Anzai, Jun-ichi,Osa, Tetsuo,Bobbitt, James M.
, p. 6469 - 6472 (1999)
Nitroxyl radical (6S,7R,10R)-4-acetylamino-2,2,7-trimethyl-10-isopropyl- 1-azaspiro[5.5]-undecane-N-oxyl reveals a reversible redox peak in cyclic voltammetry at + 0.62 V vs. Ag/AgCl. A preparative electrocatalytic oxidation of racemic sec-alcohols on the nitroxyl radical yielded mixtures of 51.4 - 63.9 % ketones and 36.1 - 48.6 % alcohols by 10 h of electrolysis. The current efficiency and turnover number of the reactions were 85.6 - 87.9 % and 20.6 - 25.6, respectively. The enantiopurity of the remaining (R)-isomers was 50 - 70 % and the S values as a selective factor was 4.1 - 4.6.
Synthesis of Visible-Light–Activated Hypervalent Iodine and Photo-oxidation under Visible Light Irradiation via a Direct S0→Tn Transition
Matsuda, Yu,Matsumoto, Koki,Nagasawa, Sho,Nakajima, Masaya,Nemoto, Tetsuhiro
, p. 235 - 239 (2022/03/16)
Heavy atom-containing molecules cause a photoreaction by a direct S0→Tn transition. Therefore, even in a hypervalent iodine compound with a benzene ring as the main skeleton, the photoreaction proceeds under 365–400nm wavelength light, where UV-visible spectra are not observed by usual measurement method. Some studies, however, report hypervalent iodine compounds that strongly absorb visible light. Herein, we report the synthesis of two visible light-absorbing hypervalent iodines and their photooxidation properties under visible light irradiation. We also demonstrated that the S0→Tn transition causes the photoreaction to proceed under wavelengths in the blue and green light region.
Direct Hydrodecarboxylation of Aliphatic Carboxylic Acids: Metal- and Light-Free
Burns, David J.,Lee, Ai-Lan,McLean, Euan B.,Mooney, David T.
, p. 686 - 691 (2022/01/28)
A mild and inexpensive method for direct hydrodecarboxylation of aliphatic carboxylic acids has been developed. The reaction does not require metals, light, or catalysts, rendering the protocol operationally simple, easy to scale, and more sustainable. Crucially, no additional H atom source is required in most cases, while a broad substrate scope and functional group tolerance are observed.
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%.
Chiral Yolk-Shell MOF as an Efficient Nanoreactor for Asymmetric Catalysis in Organic-Aqueous Two-Phase System
Shi, Shunli,Zhong, Yicheng,Hu, Zhuo,Wang, Lei,Yuan, Mingwei,Ding, Shunmin,Wang, Shuhua,Chen, Chao
supporting information, p. 12714 - 12718 (2021/09/11)
It remains a great challenge to introduce large and efficient homogeneous asymmetric catalysts into MOFs and other microporous materials as well as retain their degrees of freedom. Herein, a new heterogeneous strategy of homogeneous chiral catalysts is proposed, that is, to construct a yolk-shell MOFs-confined, large-size, and highly efficient homogeneous chiral catalyst, which can be used as a nanoreactor for asymmetric catalytic reactions.
An Artificial Light-Harvesting System with Tunable Fluorescence Color in Aqueous Sodium Dodecyl Sulfonate Micellar Systems for Photochemical Catalysis
Li, Xinglong,Wang, Ying,Song, Ao,Zhang, Minghui,Chen, Mengning,Jiang, Man,Yu, Shengsheng,Wang, Rongzhou,Xing, Lingbao
supporting information, p. 2725 - 2730 (2021/08/03)
In the present work, an artificial light-harvesting system with fluorescence resonance energy transfer (FRET) is successfully fabricated in aqueous sodium dodecyl sulfonate (SDS) micellar systems. Since the tight and orderly arrangement of dodecyl in the SDS micelles is hydrophobic, tetra-(4-pyridylphenyl)ethylene (4PyTPE) can be easily encapsulated into the hydrophobic layer of SDS micelles through noncovalent interaction, which exhibits aggregation-induced emission (AIE) phenomenon and can be used as energy donor. By using amphoteric sulforhodamine 101 (SR101) fluorescent dye attached to the negatively charged surface of SDS micelles through electrostatic interaction as energy acceptor, the light-harvesting FRET process can be efficiently simulated. Through the steady-state emission spectra analysis in the micelle-mediated energy transfer from 4PyTPE to SR101, the fluorescence emission can be tuned and white light emission with CIE coordinates of (0.31, 0.29) can be successfully achieved by tuning the donor/acceptor ratio. More importantly, to better mimic natural photosynthesis, the SDS micelles with 4PyTPE and SR101 FRET system showed enhanced catalytic activity in photochemical catalysis for dehalogenation of α-bromoacetophenone in aqueous solution and the photocatalytic reaction could be extended to gram levels.
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.
SBA-15 Supported 1-Methyl-2-azaadamanane N-Oxyl (1-Me-AZADO) as Recyclable Catalyst for Oxidation of Alcohol
Tian, Yangwu,Guo, Xiaqun,Li, Meichao,Li, Chunmei,Hu, Xinquan,Jin, Liqun,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu
supporting information, p. 3928 - 3932 (2021/05/26)
Herein, we designed and synthesized an SBA-15 supported 1-methyl-2-azaadamanane N-oxyl (1-Me-AZADO) and investigated its catalytic performance for selective oxidation of alcohols under Anelli's conditions. The first example of immobilization of 1-Me-AZADO was very important to advance the oxgenation effectively because this supported N-oxyl has excellent catalytic activity for oxidation of alcohols to carbonyl compounds, and more importantly, it can be conveniently recovered and reused at least 6 times without significant effect on its catalytic efficiency.