126002-58-2Relevant academic research and scientific papers
Alkyl-GeMe3: Neutral Metalloid Radical Precursors upon Visible-Light Photocatalysis
Wei, Li-Pu,Xiao, Bin,Xu, Qing-Hao
, (2022/02/17)
Single-electron transfer (SET) oxidation of ionic hypervalent complexes, in particular alkyltrifluoroborates (Alkyl-BF3?) and alkylbis(catecholato)silicates (Alkyl-Si(cat)2?), have contributed substantially to alkyl radical generation compared to alkali or alkaline earth organometallics because of their excellent activity–stability balance. Herein, another proposal is reported by using neutral metalloid compounds, Alkyl-GeMe3, as radical precursors. Alkyl-GeMe3 shows comparable activity to that of Alkyl-BF3? and Alkyl-Si(cat)2? in radical addition reactions. Moreover, Alkyl-GeMe3 is the first successful group 14 tetraalkyl nucleophile in nickel-catalyzed cross-coupling. Meanwhile, the neutral nature of these organogermanes offset the limitation of ionic precursors in purification and derivatization. A preliminary mechanism study suggests that an alkyl radical is generated from a tetraalkylgermane radical cation with the assistance of a nucleophile, which may also result in the development of more non-ionic alkyl radical precursors with a metalloid center.
Convenient C(sp3)-H bond functionalisation of light alkanes and other compounds by iron photocatalysis
Duan, Chunying,Jin, Yunhe,Meng, Changgong,Wang, Lifang,Wang, Xinyao,Zhang, Qingqing
supporting information, p. 6984 - 6989 (2021/09/28)
Light alkanes are natural organic carbon sources and widely distributed in nature. Transforming them into value-added fine chemicals affords attractively economic and ecological benefits as well as enormous chemical challenges. Herein, we report a practical iron-catalysed photoredox system for C(sp3)-H transformation of ethane, propane, and other light alkanes to C-N and C-C bonds under ambient temperature. The present method with abundant and inexpensive iron salts as photocatalysts exhibits high catalytic efficiency (turnover number up to 8000), mild conditions, and the convenience of being purified and scaled up without chromatography. A photo-induced ligand-to-metal charge transfer between Fe(iii) and Cl- generates a highly active chlorine radical that sequentially acts as hydrogen atom transfer catalyst. Therefore, the sustainable, convenient, and environmentally friendly system will find wide applications in high-value-added transformation of natural alkanes with novel inspiration not only for organic synthesis, but also for designing catalytically active organic/inorganic materials. This journal is
A General Organocatalytic System for Electron Donor-Acceptor Complex Photoactivation and Its Use in Radical Processes
De Pedro Beato, Eduardo,Melchiorre, Paolo,Spinnato, Davide,Zhou, Wei
supporting information, p. 12304 - 12314 (2021/08/20)
We report herein a modular class of organic catalysts that, acting as donors, can readily form photoactive electron donor-acceptor (EDA) complexes with a variety of radical precursors. Excitation with visible light generates open-shell intermediates under mild conditions, including nonstabilized carbon radicals and nitrogen-centered radicals. The modular nature of the commercially available xanthogenate and dithiocarbamate anion organocatalysts offers a versatile EDA complex catalytic platform for developing mechanistically distinct radical reactions, encompassing redox-neutral and net-reductive processes. Mechanistic investigations, by means of quantum yield determination, established that a closed catalytic cycle is operational for all of the developed radical processes, highlighting the ability of the organic catalysts to turn over and iteratively drive every catalytic cycle. We also demonstrate how the catalysts' stability and the method's high functional group tolerance could be advantageous for the direct radical functionalization of abundant functional groups, including aliphatic carboxylic acids and amines, and for applications in the late-stage elaboration of biorelevant compounds and enantioselective radical catalysis.
Electrochemical radical reactions of alkyl iodides: a highly efficient, clean, green alternative to tin reagents
Li, Diyuan,Ma, Tsz-Kan,Scott, Reuben J.,Wilden, Jonathan D.
, p. 5333 - 5338 (2020/06/04)
An electrochemical ‘redox-relay’ system has been developed which allows the generation of C-centered radicals. Intermolecular ‘tin-like’ radical reactions can subsequently be conducted under the most benign of conditions. The yields and efficiency of the processes are competitive and even superior in most cases to comparable conditions with tributyltin hydride. The use of air and electricity as the promotor (instead of a tin or other reagent) combined with the aqueous reaction media make this a clean and ‘green’ alternative to these classic C-C bond forming processes.
Catalyst-Free Decarboxylation of Carboxylic Acids and Deoxygenation of Alcohols by Electro-Induced Radical Formation
Chen, Xiaoping,Luo, Xiaosheng,Peng, Xiao,Guo, Jiaojiao,Zai, Jiantao,Wang, Ping
, p. 3226 - 3230 (2020/02/27)
Electro-induced reduction of redox active esters and N-phthalimidoyl oxalates derived from naturally abundant carboxylic acids and alcohols provides a sustainable and inexpensive approach to radical formation via undivided electrochemical cells. The resulting radicals are trapped by an electron-poor olefin or hydrogen atom source to furnish the Giese reaction or reductive decarboxylation products, respectively. A broad range of carboxylic acid (1°, 2°, and 3°) and alcohol (2° and 3°) derivatives are applicable in this catalyst-free reaction, which tolerated a diverse range of functional groups. This method features simple operation, is a sustainable platform, and has broad application.
Photochemical Strain-Release-Driven Cyclobutylation of C(sp3)-Centered Radicals
Ernouf, Guillaume,Chirkin, Egor,Rhyman, Lydia,Ramasami, Ponnadurai,Cintrat, Jean-Christophe
supporting information, p. 2618 - 2622 (2019/11/19)
A new photoredox-catalyzed decarboxylative radical addition approach to functionalized cyclobutanes is described. The reaction involves an unprecedented formal Giese-type addition of C(sp3)-centered radicals to highly strained bicyclo[1.1.0]but
Hydrosulfonylation of Unactivated Alkenes by Visible Light Photoredox Catalysis
Wang, Juan-Juan,Yu, Wei
supporting information, p. 9236 - 9240 (2019/11/19)
The anti-Markovnikov hydrosulfonylation of unactivated alkenes with sodium sulfinates was realized via [Ir(dF(CF3)ppy)2(dtbbpy)]PF6-mediated visible light photoredox catalysis. The presence of an acid such as acetic acid is essential for the reaction to take place. A variety of unactivated alkenes can be transformed into sulfones with good yield and high regioselectivity using this reaction, which is proposed to proceed by a radical mechanism.
Alkyl radical precursor and application thereof in establishing C-C bond
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Paragraph 0108; 0109; 0122, (2018/09/14)
The invention provides a precursor for generating an alkyl radical based on the visible light induction and a novel method for generating the radical. The alkyl sulfenamide is used as the radical precursor to generate the alkyl radical by virtue of the C-S bond cracking accelerated by the visible light, and then the alkyl radical is applied to the chemical reaction for establishing a C-C bond. Thereaction system has the characteristic of high efficiency, and has important scientific significance and application value for researching the novel C-C bond formation reaction, organic synthesis, drug synthesis and the like. In general, the invention provides a novel general method having practical application value. The thioalcohol (thioether) with rich resources is converted to a tool for derivating the alkyl radical.
A Desulfurative Strategy for the Generation of Alkyl Radicals Enabled by Visible-Light Photoredox Catalysis
Xue, Fei,Wang, Falu,Liu, Jiazhen,Di, Jiamei,Liao, Qi,Lu, Huifang,Zhu, Min,He, Liping,He, Huan,Zhang, Dan,Song, Hao,Liu, Xiao-Yu,Qin, Yong
supporting information, p. 6667 - 6671 (2018/06/11)
Herein, we present a new desulfurative method for generating primary, secondary, and tertiary alkyl radicals through visible-light photoredox catalysis. A process that involves the generation of N-centered radicals from sulfinamide intermediates, followed by subsequent fragmentation, is critical to forming the corresponding alkyl radical species. This strategy has been successfully applied to conjugate addition reactions that features mild reaction conditions, broad substrate scope (>60 examples), and good functional-group tolerance.
Hydroalkylation of Alkenes Using Alkyl Iodides and Hantzsch Ester under Palladium/Light System
Sumino, Shuhei,Ryu, Ilhyong
supporting information, p. 52 - 55 (2016/01/12)
The hydroalkylation of alkenes using alkyl iodides with Hantzsch ester as a hydrogen source occurred smoothly under a Pd/light system, in a novel, tin-free Giese reaction. A chemoselective reaction at C(sp3)-I in the presence of a C(sp2)-X (X = Br or I) bond was attained, which allowed for the stepwise functionalization of two types of C-X bonds in a one-pot procedure.
