32228-16-3Relevant academic research and scientific papers
Site-Selective Acceptorless Dehydrogenation of Aliphatics Enabled by Organophotoredox/Cobalt Dual Catalysis
Zhou, Min-Jie,Zhang, Lei,Liu, Guixia,Xu, Chen,Huang, Zheng
, p. 16470 - 16485 (2021/10/20)
The value of catalytic dehydrogenation of aliphatics (CDA) in organic synthesis has remained largely underexplored. Known homogeneous CDA systems often require the use of sacrificial hydrogen acceptors (or oxidants), precious metal catalysts, and harsh reaction conditions, thus limiting most existing methods to dehydrogenation of non- or low-functionalized alkanes. Here we describe a visible-light-driven, dual-catalyst system consisting of inexpensive organophotoredox and base-metal catalysts for room-temperature, acceptorless-CDA (Al-CDA). Initiated by photoexited 2-chloroanthraquinone, the process involves H atom transfer (HAT) of aliphatics to form alkyl radicals, which then react with cobaloxime to produce olefins and H2. This operationally simple method enables direct dehydrogenation of readily available chemical feedstocks to diversely functionalized olefins. For example, we demonstrate, for the first time, the oxidant-free desaturation of thioethers and amides to alkenyl sulfides and enamides, respectively. Moreover, the system's exceptional site selectivity and functional group tolerance are illustrated by late-stage dehydrogenation and synthesis of 14 biologically relevant molecules and pharmaceutical ingredients. Mechanistic studies have revealed a dual HAT process and provided insights into the origin of reactivity and site selectivity.
Electrophilic Vinylation of Thiols under Mild and Transition Metal-Free Conditions
Castoldi, Laura,Di Tommaso, Ester Maria,Gr?fen, Barbara,Olofsson, Berit,Reitti, Marcus
supporting information, p. 15512 - 15516 (2020/06/23)
The iodine(III) reagents vinylbenziodoxolones (VBX) were employed to vinylate a series of aliphatic and aromatic thiols, providing E-alkenyl sulfides with complete chemo- and regioselectivity, as well as excellent stereoselectivity. The methodology displays high functional group tolerance and proceeds under mild and transition metal-free conditions without the need for excess substrate or reagents. Mercaptothiazoles could be vinylated under modified conditions, resulting in opposite stereoselectivity compared to previous reactions with vinyliodonium salts. Novel VBX reagents with substituted benziodoxolone cores were prepared, and improved reactivity was discovered with a dimethyl-substituted core.
A Simplified Protocol for the Stereospecific Nickel-Catalyzed C-S Vinylation Using NiX 2 Salts and Alkyl Phosphites
Larin, Egor M.,Lautens, Mark,Marchese, Austin D.,Mirabi, Bijan
, p. 311 - 319 (2019/12/28)
A Ni-catalyzed C-S cross-coupling using only NiI 2 (0.5-2.5 molpercent) and P(O i Pr) 3 (2.0-10.0 molpercent) is reported. Using an air-stable Ni(II) precatalyst, and a cheap and commercially available ligand, a scalable and robust method was developed to cross-couple various thiophenols and styryl bromides, including some sterically encumbered thiols, an α-bromocinnamaldehyde as well as a thiolation-cyclization.
Acid/Phosphide-Induced Radical Route to Alkyl and Alkenyl Sulfides and Phosphonothioates from Sodium Arylsulfinates in Water
Lin, Ya-Mei,Lu, Guo-Ping,Wang, Gui-Xiang,Yi, Wen-Bin
, p. 382 - 389 (2017/04/26)
A newly developed aqueous system with acid and phosphide was introduced in which odorless and stable sodium arylsulfinates can in situ generate arylsulfenyl radicals. These radicals have high reactivity to react with alkynes, alkenes, and H-phosphine oxides for the synthesis of alkyl and alkenyl sulfides and phosphonothioates. The control experiments and quantum calculations are also performed to gain insights into the generation mechanism of arylsulfenyl radicals. Notably, the chemistry is free of thiol odors, organic solvents, and metals.
Alkenyl preparation method of sulfide
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Paragraph 0062-0064, (2017/03/23)
The invention discloses a method for preparing alkenyl sulfide. The method comprises the following steps: adding a styrene derivative of the formula I as shown in the specification into a disulfide compound of the formula II as shown in the specification,
Sulfamic acid: An efficient and recyclable catalyst for the regioselective hydrothiolation of terminal alkenes and alkynes with thiols
Rosa, Clarissa Helena,Peixoto, Maura Luise B.,Rosa, Gilber Ricardo,Godoi, Benhur,Galetto, Fábio Zazyki,D'Oca, Marcelo Gon?alves Montes,Godoi, Marcelo
supporting information, p. 3777 - 3781 (2017/09/09)
Herein, we described a new method for the preparation of thioethers through hydrothiolation of alkenes and alkynes, using sulfamic acid as a reusable catalyst. Generally, this new methodology afforded the desired products in very good yields, under metal
Stereoselective Synthesis of Alkenyl Silanes, Sulfones, Phosphine Oxides, and Nitroolefins by Radical C-S Bond Cleavage of Arylalkenyl Sulfides
Lin, Ya-mei,Lu, Guo-ping,Wang, Rong-kang,Yi, Wen-bin
supporting information, p. 1100 - 1103 (2017/03/15)
A radical-mediated approach has been introduced for the C-S bond activation of arylalkenyl sulfides. The protocol provides an efficient approach for the generation of various alkenes including alkenyl silanes, sulfones, phosphine oxides, and nitroolefins. In most cases, these radical substitutions are performed under metal-free conditions with stereospecificity.
Copper-mediated stereospecific C-H oxidative sulfenylation of terminal alkenes with disulfides
Tu, Hai-Yong,Hu, Bo-Lun,Deng, Chen-Liang,Zhang, Xing-Guo
supporting information, p. 15558 - 15561 (2015/10/28)
A copper and iodine-mediated C-H oxidative sulfenylation of olefins with diaryl disulfides has been developed for the stereospecific synthesis of vinyl thioether. With the combination of Cu(OTf)2 and I2, a variety of terminal alkenes
Highly stereoselective anti-Markovnikov hydrothiolation of alkynes and electron-deficient alkenes by a supported Cu-NHC complex
Yang, Yong,Rioux, Robert M.
, p. 3916 - 3925 (2014/08/05)
A practical, efficient, and low-cost heterogeneous catalyst consisting of a Cu-NHC (N-heterocyclic carbene) complex grafted to SBA-15 silica for the catalytic hydrothiolation of alkynes and electron-deficient alkenes under mild reaction conditions has been developed. The heterogeneous catalyst displays higher activity and stereoselectivity to Z-anti-Markovnikov isomers compared with the homogeneous analog under otherwise identical reaction conditions. The catalytic system is applicable to a broad range of alkynes and thiols and is recyclable without significant loss in catalytic performance. High activity and perfect selectivity to alkyl sulfides formed by the addition of electron-deficient alkenes to various thiols catalyzed by the supported Cu-NHC complex were also realized. This journal is the Partner Organisations 2014.
Stereoselective formation of Z- or E-vinyl thioethers from arylthiols and acetylenes under transition-metal-free conditions
Liao, Yunfeng,Chen, Shanping,Jiang, Pengcheng,Qi, Hongrui,Deng, Guo-Jun
, p. 6878 - 6885 (2013/11/06)
Vinyl sulfide formation with good yield and high regio- and stereoselectivities from thiols and acetylenes under transition-metal-free conditions is described. Potassium phosphate was used as an effective additive to enhance the reaction yield and selecti
