- Straightforward Access to Thiocyanates via Dealkylative Cyanation of Sulfoxides
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Thiocyanates, versatile building blocks in organic synthesis, are shown to be easily accessible via an interrupted Pummerer reaction of sulfoxides. This facile dealkylative functionalization proceeds under mild conditions through electrophilic activation of the sulfoxide partner. The resulting thiocyanate itself can serve as a handle for diversification in a straightforward one-pot procedure.
- Todorovi?, Uro?,Klose, Immo,Maulide, Nuno
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supporting information
p. 2510 - 2513
(2021/04/13)
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- 5-(Cyano)dibenzothiophenium Triflate: A Sulfur-Based Reagent for Electrophilic Cyanation and Cyanocyclizations
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The synthesis of 5-(cyano)dibenzothiophenium triflate 9, prepared by activation of dibenzo[b,d]thiophene-5-oxide with Tf2O and subsequent reaction with TMSCN is reported, and its reactivity as electrophilic cyanation reagent evaluated. The scalable preparation, easy handling and broad substrate scope of the electrophilic cyanation promoted by 9, which includes amines, thiols, silyl enol ethers, alkenes, electron rich (hetero)arenes and polyaromatic hydrocarbons, illustrate the synthetic potential of this reagent. Importantly, Lewis acid activation of the reagent is not required for the transfer process. We additionally report herein biomimetic cyanocyclization cascade reactions, which are not promoted by typical electrophilic cyanation reagents, demonstrating the superior ability of 9 to trigger challenging transformations.
- Li, Xiangdong,Golz, Christopher,Alcarazo, Manuel
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supporting information
p. 9496 - 9500
(2019/06/27)
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- Electrochemical ipso-Thiocyanation of Arylboron Compounds
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An operationally simple electrochemical method for the transition-metal-free ipso-thiocyanation of arylboronic acids and aryl trifluoroborates has been developed. The SCN electrophile is generated in situ by anodic oxidation of thiocyanate anions, which avoids formation of salt waste and prevents unwanted side reactions arising from chemical oxidants. The reaction proceeds regiospecifically, and the scope extends to non-activated aromatic systems. (Figure presented.).
- Dyga, Marco,Hayrapetyan, Davit,Rit, Raja K.,Goo?en, Lukas J.
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supporting information
p. 3548 - 3553
(2019/04/26)
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- Copper-Catalyzed Electrophilic Thiolation of Organozinc Halides by Using N-Thiophthalimides Leading to Polyfunctional Thioethers
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(Hetero)aryl, benzylic, and alkyl zinc halides were thiolated with N-thiophthalimides at 25 °C within 1 h in the presence of 5–10 % Cu(OAc)2?H2O to furnish the corresponding polyfunctionalized thioethers in good yields. This electrop
- Gra?l, Simon,Hamze, Clémence,Koller, Thadd?us J.,Knochel, Paul
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p. 3752 - 3755
(2019/02/13)
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- N -Thiocyanato-dibenzenesulfonimide: A new electrophilic thiocyanating reagent with enhanced reactivity
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A novel electrophilic thiocyanating reagent, N-thiocyanato-dibenzenesulfonimide, was prepared and exhibited enhanced electrophilicity with a wide scope of substrates. Thus, it reacted with activated aromatics such as phenols, indoles, anilines and anisoles without a catalyst giving the corresponding thicyanate derivatives in high yields, while TfOH for unactivated arenes and hetero aromatics and Zn(OTf)2 for ketones was used as the catalyst, respectively. It is noteworthy that internal alkenes and styrenes were bifunctionalized giving 1,2-amino thiocyanates in high yields.
- Li, Chengqiu,Long, Pingliang,Wu, Haopeng,Yin, Hongquan,Chen, Fu-Xue
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supporting information
p. 7131 - 7134
(2019/08/07)
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- Synthesis of Aryl Tri- and Difluoromethyl Thioethers via a C H-Thiocyanation/Fluoroalkylation Cascade
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An AlCl3-catalyzed C H thiocyanation was discovered and combined with a Langlois-type trifluoromethylation to afford aryl trifluoromethyl thioethers directly from arenes, N-thiocyanatosuccinimide (NTS) and Ruppert-Prakash reagent. An analogous combination with a copper-mediated difluoromethylation gives access to aryl difluoromethyl thioethers. Both processes proceed with exceptional regioselectivity for the most electron-rich, sterically least hindered position of the arene. The sulfur and fluoroalkyl groups originate from different sources, so that the use of expensive, preformed fluoroalkylthiolation reagents is avoided. Perfectly formed: An AlCl3-catalyzed C H thiocyanation was combined with a Langlois-type trifluoromethylation to afford aryl trifluoromethyl thioethers directly from arenes, N-thiocyanatosuccinimide, and TMS-CF3 (see scheme). An analogous combination of the thiocyanation with a copper-mediated difluoromethylation gives access to aryl difluoromethyl thioethers. The sulfur and fluoroalkyl groups originate from different sources, so that preformed fluoroalkylthiolation reagents are avoided.
- Jouvin, Kévin,Matheis, Christian,Goossen, Lukas J.
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supporting information
p. 14324 - 14327
(2015/10/05)
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- Preparation of arylthiocyanates using N,N′-dibromo-N,N′-bis(2, 5-dimethylbenzenesulphonyl) ethylenediamine and N,N-dibromo-2,5- dimethylbenzenesulphonamide in the presence of KSCN as a novel thiocyanating reagent
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N-Bromosulphonamides, synthesized via direct bromination of sulphonamides, react with several types of arene substrates in the presence of KSCN to afford aryl thiocyanates. The method appears to be generally applicable to benzenoid substrates with a wide
- Khazaei, Ardeshir,Alizadeh, Abdolhamid,Vaghei, Ramin Ghorbani
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p. 253 - 257
(2007/10/03)
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- NEW METHODS AND REAGENTS IN ORGANIC SYNTHESIS. 23. DIETHYL PHOSPHOROCYANIDATE(DEPC): A USEFUL REAGENT FOR AN UNPRECEDENTED TRANSFORMATION OF SULFINIC ACIDS TO THIOCYANATES
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Diethyl phosphorocyanidate(DEPC) can be efficiently used for a simple, one-step transformation of sulfinic acids to thiocyanates.
- Harusawa, Shinya,Shioiri, Takayuki
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p. 447 - 448
(2007/10/02)
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- Dediazoniation of Arenediazonium Ions. Part XIX. Effect of Thiocyanate Ion in the Reactions of 2,4,6-Trimethylbenzenediazonium Tetrafluoroborate in 2,2,2-trifluoroethanol
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The dediazoniation of 2,4,6-trimethylbenzenediazonium tetrafluoroborate (1) in 2,2,2-trifluoroethanol (TFE) was studied in the presence of potassium thiocyanate.The effect of added salt on the dediazoniation rate, the Nα-Nβ rearrangement (Eqn. 2), the exchange of the 15N-labelled diazo group with molecular nitrogen (Eqn. 3), and the reaction products was determinated.With 0.3M KSCN a dediazoniation-rate increase of 16.5percent was achieved, and the amounts of rearranged and exchanged product were reduced to 88percent and 70percent, respectively, of the values found in pure TFE.The dediazoniation products formed are ArF (3), ArOCH2CF3 (4), ArSCN (5), ArNCS (6) and traces of 5,7-dimethylindazole (7).All the data are in agreement with, and support the previously proposed mechanism (Eqn. 1) of heterolytic dediazoniation of arenediazonium salts.
- Szele, Ivanka,Zollinger, Heinrich,Deshpande, Ashok D.
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p. 2721 - 2727
(2007/10/02)
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