2919-20-2Relevant academic research and scientific papers
Selective synthesis of iminodioxaspirononanes and diazaspirononanes using formic acid-activated Mn(III) oxidation of N1,N3-disubstitued malonamides with 1,1-diarylethenes
El-Deeb, Ibrahim Yussif,Nakano, Y?ki,Nishino, Hiroshi,Shimoishi, Ryutaro,Wada, Ryosei
, (2021/12/30)
The Mn(III)-based oxidation of N1,N3-disubstituted malonamides with alkenes by Kurosawa spirolactonization using malonic acid afforded iminodihydrofurans. A similar reaction with Mn(OAc)3, which was activated by HCO2
Radical C(sp3)-H Heck-type Reaction of N-Alkoxybenzimidoyl Chlorides with Styrenes to Construct Alkenols
Fang, Di,Zhang, Yidan,Chen, Yiyun
supporting information, p. 2050 - 2054 (2022/03/17)
We report the first radical C(sp3)-H Heck-type reaction of aliphatic alcohols for selective δ- and ?-alkenol synthesis by photoredox catalysis. N-Alkoxybenzimidoyl chlorides are developed as novel alkoxyl radical precursors with tunable redox potentials. Various alkenols can be constructed by the inert C(sp3)-H Heck-type reaction of 4-cyano-N-alkoxybenzimidoyl chlorides with styrene derivatives under redox-neutral conditions, which can be performed on the gram scale and can be easily derivatized.
Photoinduced Hydroarylation and Cyclization of Alkenes with Luminescent Platinum(II) Complexes
Cheng, Hanchao,Lam, Tsz-Lung,Liu, Yungen,Tang, Zhou,Che, Chi-Ming
supporting information, p. 1383 - 1389 (2020/11/30)
Photoinduced hydroarylation of alkenes is an appealing synthetic strategy for arene functionalization. Herein, we demonstrated that aryl radicals generated from electron-deficient aryl chlorides/bromides could be trapped by an array of terminal/internal aryl alkenes in the presence of [Pt(O^N^C^N)] under visible-light (410 nm) irradiation, affording anti-Markovnikov hydroarylated compounds in up to 95 % yield. Besides, a protocol for [Pt(O^N^C^N)]-catalyzed intramolecular photocyclization of acrylanilides to give structurally diverse 3,4-dihydroquinolinones has been developed.
Direct Allylic C(sp3)?H and Vinylic C(sp2)?H Thiolation with Hydrogen Evolution by Quantum Dots and Visible Light
Huang, Cheng,Ci, Rui-Nan,Qiao, Jia,Wang, Xu-Zhe,Feng, Ke,Chen, Bin,Tung, Chen-Ho,Wu, Li-Zhu
supporting information, p. 11779 - 11783 (2021/04/21)
Direct allylic C?H thiolation is straightforward for allylic C(sp3)?S bond formation. However, strong interactions between thiol and transition metal catalysts lead to deactivation of the catalytic cycle or oxidation of sulfur atom under oxidative condition. Thus, direct allylic C(sp3)?H thiolation has proved difficult. Represented herein is an exceptional for direct, efficient, atom- and step-economic thiolation of allylic C(sp3)?H and thiol S?H under visible light irradiation. Radical trapping experiments and electron paramagnetic resonance (EPR) spectroscopy identified the allylic radical and thiyl radical generated on the surface of photocatalyst quantum dots (QDs). The C?S bond formation does not require external oxidants and radical initiators, and hydrogen (H2) is produced as byproduct. When vinylic C(sp2)?H was used instead of allylic C(sp3)?H bond, the radical-radical cross-coupling of C(sp2)?H and S?H was achieved with liberation of H2. Such a unique transformation opens up a door toward direct C?H and S?H coupling for valuable organosulfur chemistry.
Visible-Light-Induced Meerwein Fluoroarylation of Styrenes
Tang, Hai-Jun,Zhang, Bin,Xue, Fei,Feng, Chao
supporting information, p. 4040 - 4044 (2021/05/26)
An unprecedented approach for assembling a broad range of 1,2-diarylethane derivatives with fluorine-containing fully substituted carbon centers was developed. The protocol features straightforward operation, proceeds under metal-free condition, and accommodates a large variety of synthetically useful functionalities. The critical aspect to the success of this novel transformation lies in using aryldiazonium salts as both aryl radical progenitor and also as single electron acceptor which elegantly enables a radical-polar crossover manifold.
TMSOTf-mediated synthesis of skipped dienes through the addition of olefins to imines and semicyclicN,O-acetals
Feng, Yi-Man,Nie, Xiao-Di,Sun, Jian-Ting,Xu, Wen-Ke,Wei, Bang-Guo
, p. 7883 - 7893 (2021/09/28)
A novel approach to skipped dienes has been developed through the TMSOTf-mediated one-pot addition-substitution of olefins2a,2fand2gwith imines1a-1g, and a series of aryl substituted skipped dienes3aa-3gfwere accordingly obtained in 62%-94% yields. Moreov
Visible-Light Photoredox-Catalyzed Dicarbofunctionalization of Styrenes with Oxime Esters and CO2: Multicomponent Reactions toward Cyanocarboxylic Acids and γ-Keto Acids
Bai, Junxue,Li, Miao,Zhou, Cong,Sha, Yu,Cheng, Jiang,Sun, Jianwei,Sun, Song
supporting information, p. 9654 - 9658 (2021/12/14)
A photoredox-catalyzed dicarbofunctionalization of styrenes with oxime esters and CO2 has been achieved. Notably, a series of four-, five-, or six-membered cyclic ketone oximes worked well to furnish a wide range of ε-, ζ-, and η-cyanocarboxylic acids in good yields. Furthermore, a series of γ-keto acids also could be obtained by employing acyclic ketone oxime esters as the carbonyl radical precursor. It provides convergent access to diverse biologically important cyanocarboxylic and γ-keto acids.
Photoredox-Catalyzed α-Aminomethyl Carboxylation of Styrenes with Sodium Glycinates: Synthesis of γ-Amino Acids and γ-Lactams
Zhou, Cong,Li, Miao,Sun, Jianwei,Cheng, Jiang,Sun, Song
supporting information, p. 2895 - 2899 (2021/05/05)
A visible-light photoredox-catalyzed reductive α-aminomethyl carboxylation of styrenes with sodium glycinates and CO2 has been developed to synthesize a series of α,α-disubstituted γ-amino acids and γ-lactams with high efficiency and regioselectivity. Notably, CO2 released from the decarboxylation step can be reused for the subsequent carboxylation. Distinct from the previous reactions with the same type of substrates leading to simple decarboxylation and olefin hydroalkylation, this process involves additional CO2 sequestration, thus leading to olefin α-aminomethyl carboxylation. These findings not only provide new access to α,α-disubstituted γ-amino acids and γ-lactams but also serve as a proof of concept for CO2 reutilization in decarboxylation reactions.
Photoredox-Catalyzed Addition of Carbamoyl Radicals to Olefins: A 1,4-Dihydropyridine Approach
Cardinale, Luana,Konev, Mikhail O.,Jacobi von Wangelin, Axel
supporting information, p. 8239 - 8243 (2020/06/20)
Functionalization with C1-building blocks are key synthetic methods in organic synthesis. The low reactivity of the most abundant C1-molecule, carbon dioxide, makes alternative carboxylation reactions with CO2-surrogates especially important. We report a photoredox-catalyzed protocol for alkene carbamoylations. Readily accessible 4-carboxamido-Hantzsch esters serve as convenient starting materials that generate carbamoyl radicals upon visible light-mediated single-electron transfer. Addition to various alkenes proceeded with high levels of regio- and chemoselectivity.
Cu/Ni-Catalyzed Cyanomethylation of Alkenes with Acetonitrile for the Synthesis of β,γ-Unsaturated Nitriles
Jian, Hong,Shen, Zengming,Zhang, Saisai
, p. 6143 - 6150 (2020/05/22)
We have developed a protocol for the Cu/Ni-catalyzed cyanomethylation of alkenes with acetonitrile for the synthesis of β,γ-unsaturated nitriles. This is the first example of a direct coupling of the alkene sp2 C - H bond and the acetonitrile sp3 C - H bond for the preparation of β,γ-unsaturated nitriles. Acetonitrile, an inexpensive and stable solvent, is demonstrated to be a useful cyanomethyl source. The combination of copper and nickel catalysts resulted in a high reaction efficiency.
