24466-59-9Relevant academic research and scientific papers
Umpolung Difunctionalization of Carbonyls via Visible-Light Photoredox Catalytic Radical-Carbanion Relay
Wang, Shun,Cheng, Bei-Yi,Sr?en, Matea,K?nig, Burkhard
supporting information, p. 7524 - 7531 (2020/08/05)
The combination of photoredox catalysis with the Wolff-Kishner (WK) reaction allows the difunctionalization of carbonyl groups by a radical-carbanion relay sequence (photo-Wolff-Kishner reaction). Photoredox initiated radical addition to N-sulfonylhydrazones yields α-functionalized carbanions following the WK-type mechanism. With sulfur-centered radicals, the carbanions are further functionalized by reaction with electrophiles including CO2 and aldehydes, whereas CF3 radical addition furnishes a wide range of gem-difluoroalkenes through β-fluoride elimination of the generated α-CF3 carbanions. More than 80 substrate examples demonstrate the broad applicability of this reaction sequence. A series of investigations including radical inhibition, deuterium labeling, fluorescence quenching, cyclic voltammetry, and control experiments support the proposed radical-carbanion relay mechanism.
Pd-Catalyzed Alkenyl Thioether Synthesis from Thioesters and N-Tosylhydrazones
Ishitobi, Kota,Muto, Kei,Yamaguchi, Junichiro
, p. 11685 - 11690 (2019/12/02)
A Pd-catalyzed alkenyl thioether synthesis was achieved using thioesters and N-tosylhydrazones as starting materials. The thioester acted as an efficient "sulfur source" for catalytic C-S bond formation using N-tosylhydrazone. This method gave Z-alkenyl thioethers with high diastereoselectivity (up to 99:1 diastereomeric ratio). This transformation displayed a wide functional group tolerance and was successfully applied to the late-stage derivatization of a pharmaceutical molecule to the corresponding alkenyl thioether.
Nickel-Catalyzed Regioselective Cleavage of Csp2-S Bonds: Method for the Synthesis of Tri- and Tetrasubstituted Alkenes
Chen, Jinyang,Chen, Sihai,Xu, Xinhua,Tang, Zhi,Au, Chak-Tong,Qiu, Renhua
, p. 3246 - 3255 (2016/05/19)
We describe here an efficient route for the synthesis of (Z)-vinylic sulfides 3 via the highly regio- and stereoselective coupling of (Z)-1,2-bis(aryl(alkyl)thio)alkenes and Grignard reagents over a Ni catalyst under mild conditions. (Z)-Vinylic sulfides 3 are important intermediates in the synthesis of tri- and tetrasubstituted alkenes that are important construction blocks for drugs and natural products. The directing organosulfur groups (SR) can be converted to diaryl(alkyl) disulfides (RSSR) using H2O2 as oxidant, hence avoiding the waste of sulfur resources. The protocol provides a general method that is highly regio- and stereoselective for the synthesis of a diversity of tri- and tetrasubstituted 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.
An operationally simple approach to (E)-α-halo vinyl sulfides and their applications for accessing stereodefined trisubstituted alkenes
Yang, Zhaozhen,Chen, Xiaoyi,Kong, Wei,Xia, Siyuan,Zheng, Renwei,Luo, Fang,Zhu, Gangguo
, p. 2175 - 2185 (2013/04/10)
An operationally simple and practical protocol for the synthesis of (E)-α-halo vinyl sulfides has been achieved via a highly regio- and stereoselective hydrohalogenation of alkynyl thioethers using lithium halides in HOAc or propionic acid at room temperature. It permits the formation of (E)-α-chloro and (E)-α-bromo vinyl sulfides in satisfactory yields with good to excellent stereoselectivities. Moreover, this work results in a new method for the assembly of stereodefined (E)- or (Z)-trisubstituted alkenes featuring the first coupling of the C-X bond of (E)-α-halo vinyl sulfides followed by a subsequent Ni-catalyzed coupling of the C-S bond with Grignard reagents. The Royal Society of Chemistry 2013.
Alkyne hydrothiolation catalyzed by a dichlorobis(aminophosphine) complex of palladium: Selective formation of cis-configured vinyl thioethers
Gerber, Roman,Frech, Christian M.
scheme or table, p. 8901 - 8905 (2012/09/25)
Cis all round: Dichlorobis[1-(dicyclohexylphosphanyl)piperidine]palladium, [(P{(NC5H10)(C6H11) 2})2Pd(Cl)2], is a highly efficient alkyne hydrothiolation catalyst and the first generally applicable system that selectively generates cis-configured anti-Markovnikov adducts in excellent yields within only a few minutes at 120 °C in the presence of only 0.05 mol % of the catalyst (see scheme).
Regio- and stereoselective copper-catalyzed addition of aromatic and aliphatic thiols to terminal and internal nonactivated alkynes
Trostyanskaya, Inna G.,Beletskaya, Irina P.
scheme or table, p. 535 - 540 (2012/04/10)
The CuI-catalyzed regio- and stereoselective hydrothio-lation of terminal and internal alkynes affords (Z) - alkenylsulfides. The following isomerization of the Z-isomers into E-isomers catalyzed by CuI is described. Georg Thieme Verlag Stuttgart · New Yo
A one-pot, stereoselective synthesis of (Z)-1,2-disubstituted vinyl sulfides by sequential hydrostannylation and Stille reaction of acetylenic sulfides with tributyltin hydride and then with aryl iodides
Hao, Wenyan,Wang, Dong,Cai, Mingzhong
, p. 418 - 419 (2008/09/16)
(Z)-1,2-Disubstituted vinyl sulfides can be stereoselectively synthesised in one pot under mild conditions, in good yields, by the palladium-catalysed hydrostannylation of acetylenic sulfides, followed by Stille coupling with aryl iodides.
Stereoselective synthesis of (Z)-α-organothiovinyltosylates and their application in the synthesis of highly functionalized vinylic sulfides
Braga,Emmerich,Silveira,Martins,Rodrigues
, p. 371 - 373 (2007/10/03)
Thioacetylenes 1 afford, upon treatment with p-toluenesulfonic acid in dichloromethane, (O,S)-ketene acetals 2 which can act as useful α-(organothio)vinyl carbocation equivalents, opening a novel route to functionalized vinylic sulfides.
Aryl 1-chloroalkyl sulfoxides as acyl anion equivalents: A new synthesis of vinyl sulfides, ketones, and diketones from aryl 1-chloroalkyl sulfoxides and α,ω-dichloro-α,ω-disulfinylalkanes
Satoh, Tsuyoshi,Taguchi, Daisaku,Suzuki, Chihiro,Fujisawa, Satoshi
, p. 493 - 500 (2007/10/03)
Treatment of aryl α-chloroalkyl sulfoxides, which were synthesized from aryl 1-chloroalkyl sulfoxides by alkylation with iodoalkanes, with trifluoroacetic anhydride and NaI in acetone at low temperature afforded vinyl sulfides in high yields. The vinyl sulfides were converted to ketones by hydrolysis with HClO4 in refluxing 1,4-dioxane in good yields. In this procedure, the lithiated aryl 1-chloroalkyl sulfoxides acted as acyl anion equivalents. The procedure was extended to a synthesis of α,ω-diketones starting from α,ω-dichloro-α,ω-disulfinylalkanes. The procedure was found to work well when the length of the carbon chain of the α,ω-disulfinylalkanes is longer than four, and the yields of the diketones were found to be somewhat variable (60-80%).
