41830-99-3

Upstream product

• 2923-16-2 potassium trifluoroacetate 
• 1137-41-3 (4-aminophenyl)(phenyl)methanone 
• 6136-66-9 4-iodobenzophenone 
• 3872-23-9 Copper(I) trifluoromethanethiolate 
• 124643-34-1 p-benzoylphenyl triflate 
• 811-68-7 silver(I) trifluoromethanethiolate 
• 134-85-0 4-chlorobenzophenone 
• 81290-20-2 (trifluoromethyl)trimethylsilane 
• 90-90-4 (4-bromophenyl)(phenyl)methanone 

Downstream Products

• 41831-00-9 [1-Phenyl-1-(4-trifluoromethylsulfanyl-phenyl)-meth-(E)-ylidene]-hydrazine 

Relevant academic research and scientific papers

Fundamental studies and development of nickel-catalyzed trifluoromethylthiolation of aryl chlorides: Active catalytic species and key roles of ligand and traceless MeCN additive revealed

A catalytic protocol to convert aryl and heteroaryl chlorides to the corresponding trifluoromethyl sulfides is reported herein. It relies on a relatively inexpensive Ni(cod)2/dppf (cod = 1,5-cyclooctadiene; dppf = 1,1′-bis(diphenylphosphino)ferrocene) catalyst system and the readily accessible coupling reagent (Me4N)SCF3. Our computational and experimental mechanistic data are consistent with a Ni(0)/Ni(II) cycle and inconsistent with Ni(I) as the reactive species. The relevant intermediates were prepared, characterized by X-ray crystallography, and tested for their catalytic competence. This revealed that a monomeric tricoordinate Ni(I) complex is favored for dppf and Cl whose role was unambiguously assigned as being an off-cycle catalyst deactivation product. Only bidentate ligands with wide bite angles (e.g., dppf) are effective. These bulky ligands render the catalyst resting state as [(P-P)Ni(cod)]. The latter is more reactive than Ni(P-P)2, which was found to be the resting state for ligands with smaller bite angles and suffers from an initial high-energy dissociation of one ligand prior to oxidative addition, rendering the system unreactive. The key to effective catalysis is hence the presence of a labile auxiliary ligand in the catalyst resting state. For more challenging substrates, high conversions were achieved via the employment of MeCN as a traceless additive. Mechanistic data suggest that its beneficial role lies in decreasing the energetic span, therefore accelerating product formation. Finally, the methodology has been applied to synthetic targets of pharmaceutical relevance.

Metal-Free Trifluoromethylthiolation of Arylazo Sulfones

A visible-light-driven protocol for the synthesis of aryl trifluoromethyl thioethers under photocatalyst- and metal-free conditions has been pursued. The procedure exploits the peculiar properties of arylazo sulfones (having electron-rich or electron-poor substituents on the (hetero)aromatic ring) as photochemical precursors of aryl radicals and S-trifluoromethyl arylsulfonothioates as easy-to-handle trifluoromethylthiolating agents.

Metal-free trifluoromethylthiolation of arenediazonium salts with Me4NSCF3

A metal-free entry to the pharmaceutically meaningful substrate class of trifluoromethyl thioethers has been developed starting from widely available arenediazonium salts and commercially available Me4N+SCF3?. This reaction proceeds within one hour at 0 °C and is applicable to a wide range of functionalized substrates.

Trifluoromethylthiolation of Unsymmetrical λ3-Iodane Derivatives: Additive-Free, Selective and Scalable Introduction of the SCF3 Group

The reaction of copper trifluoromethyl sulfide with diaryliodonium salts provides a straightforward pathway for the synthesis of aryl trifluoromethyl thioethers under mild reaction conditions and within short reaction times. High chemoselectivity was achieved by using mesityl as a leaving group. A large range of novel [(het)aryl](mesityl)iodonium salts underwent this reaction under the optimized conditions to give the desired products in moderate to good yields.

Nickel-catalyzed trifluoromethylthiolation of Csp2-O bonds

While nickel catalysts have previously been shown to activate even the least reactive Csp2-O bonds, i.e. aryl ethers, in the context of C-C bond formation, little is known about the reactivity limits and molecular requirements for the introduction of valuable functional groups under homogeneous nickel catalysis. We identified that due to the high reactivity of Ni-catalysts, they are also prone to react with existing or installed functional groups, which ultimately causes catalyst deactivation. The scope of the Ni-catalyzed coupling protocol will therefore be dictated by the reactivity of the functional groups towards the catalyst. Herein, we showed that the application of computational tools allowed the identification of matching functional groups in terms of suitable leaving groups and tolerated functional groups. This allowed for the development of the first efficient protocol to trifluoromethylthiolate Csp2-O bonds, giving the mild and operationally simple C-SCF3 coupling of a range of aryl, vinyl triflates and nonaflates. The novel methodology was also applied to biologically active and pharmaceutical relevant targets, showcasing its robustness and wide applicability.

Sandmeyer-Type Trifluoromethylthiolation and Trifluoromethylselenolation of (Hetero)Aromatic Amines Catalyzed by Copper

Aromatic and heteroaromatic diazonium salts were efficiently converted into the corresponding trifluoromethylthio- or selenoethers by reaction with Me4NSCF3 or Me4NSeCF3, respectively, in the presence of catalytic amounts of copper thiocyanate. These Sandmeyer-type reactions proceed within one hour at room temperature, are applicable to a wide range of functionalized molecules, and can optionally be combined with the diazotizations into one-pot protocols.

Iron-Catalyzed Decarboxylation of Trifluoroacetate and Its Application to the Synthesis of Trifluoromethyl Thioethers

Nucleophilic CF3 has been generated by decarboxylation of potassium trifluoroacetate, arguably the most easy-to-handle, inexpensive, and sustainable source of trifluoromethyl groups. Simple iron(II) chloride catalyzes the decarboxylation as well as a subsequent trifluoromethylation of organothiocyanates, resulting in a straightforward synthesis of trifluoromethyl thioethers. The KCN byproduct is absorbed by iron(II) with formation of nontoxic potassium hexacyanoferrate. An analogous trifluoromethylation of aldehydes with trifluoroacetate underlines the synthetic potential of such iron-catalyzed decarboxylative trifluoromethylations.

Copper-Catalyzed Trifluoromethylthiolation of Di(hetero)aryl-λ3-iodanes: Mechanistic Insight and Application to Synthesis of (Hetero)Aryl Trifluoromethyl Sulfides

The direct and regioselective copper/S-Phos-catalyzed trifluoromethylthiolation of symmetrical and unsymmetrical di(hetero)aryl-λ3-iodanes has been accomplished for the synthesis of various (hetero)aryl trifluoromethyl sulfides employing readily accessible silver trifluoromethylthiolate (AgSCF3) as nucleophilic trifluoromethylthiolating reagent. The developed transformation tolerates various functional groups like nitrile, enolizable ketone, ester, nitro and free carboxylic acid. Interestingly, the formal trifluoromethylthiolation of arenes was also achieved through integration of the synthesis of diaryl-λ3-iodanes from arenes with the trifluoromethylthiolation. Mechanistic investigations did not favor the radical formation and SET pathway. Based on the variable temperature 19F NMR spectroscopy, isolation of the most relevant catalytic intermediate, and stoichiometric studies supported the Cu(I)/Cu(III) catalytic cycle, wherein the oxidative addition of diaryl-λ3-iodanes was assisted by the silver salt.

Mild and Soft Catalyzed Trifluoromethylthiolation of Boronic Acids: The Crucial Role of Water

The most reactive 2nd generation of trifluoromethanesulfenamides undergoes a copper-catalyzed cross-coupling reaction with boronic acids to afford CF3S-molecules. Contrary to the previous methods in the literature, no base addition, no heating, and no large excess of reagents are required to obtain good results. Furthermore, a crucial role of a small amount of water to favor this reaction has been demonstrated. This constitutes the mildest described conditions for such a reaction.

Sandmeyer trifluoromethylthiolation of arenediazonium salts with sodium thiocyanate and Ruppert-Prakash reagent

In the presence of copper thiocyanate, sodium thiocyanate and the inexpensive, easy-to-use trifluoromethylating reagent Me3Si-CF 3, diazonium salts are smoothly converted into the corresponding aryl trifluoromethyl thioethers. Combin