The preparation of heteroaryl trifluoromethyl selenoethers by the trifluoromethylselenolation of heteroaryl bromides with [(bpy)CuSeCF₃]₂ was investigated. Using this approach, a large number of trifluoromethylselenolated heterocyclic compounds were synthesized in good to excellent yields. It was demonstrated that this procedure tolerates a wide variety of functional groups.

This article describes the new economic decarboxylative trifluoromethylating reagent [Cu(phen)(O₂CCF₃)] (1; phen=1,10-phenanthroline) and the efficient difluorocarbene precursor [Cu(phen)₂][O₂CCF₂Cl] (2). Treatment of copper tert-butoxide with phen and subsequent addition of trifluoroacetic acid or chlorodifluoroacetic acid afforded air-stable complexes 1 and 2, respectively, which were characterized by X-ray crystallography. The copper(I) ion in 1 is coordinated by a bidentate phen ligand, a monodentate trifluoroacetate group, and a molecule of CH₃CN in a distorted tetrahedral coordination geometry. The molecular structure of 2 adopts an ionic form that consists of a [Cu(phen)₂]⁺ cation and a chlorodifluoroacetate anion. Complex 1 reacted with a variety of aryl and heteroaryl halides to form trifluoromethyl (hetero)arenes in good yields. The corresponding Hammett plot exhibited a linear relationship and a reaction parameter (ρ)=+0.56±0.02, which indicated that the trifluoromethylation reaction proceeded via a nucleophilic reactive species. Complex 2 reacts with phenols to produce aryl difluoromethyl ethers in modest-to-excellent yields. Mechanistic investigations revealed that the difluoromethylation reaction proceeds by initial copper-mediated formation of difluorocarbene and subsequent concerted addition of difluorocarbene to the phenol to form a three-center transition state.

Copper(I) fluoroalkoxide complexes bearing dinitrogen ligands were synthesized and the structure and reactivity of the complexes toward trifluoroethoxylation, pentafluoropropoxylation, and tetrafluoropropoxylation of aryl and heteroaryl bromides were investigated.

Copper(I) fluoroalkoxide complexes bearing dinitrogen ligands were synthesized and the structure and reactivity of the complexes toward trifluoroethoxylation, pentafluoropropoxylation, and tetrafluoropropoxylation of aryl and heteroaryl bromides were investigated.

An efficient method is reported for the copper(I)-catalyzed trifluoromethylthiolation of allylic bromides by using elemental sulfur and CF₃SiMe₃. This rate of this transformation was significantly accelerated in the presence of 18-crown-6, and the reaction afforded the desired products in moderate to excellent yields with high stereo- and regioselectivity. This method can tolerate a number of functional groups and provides facile access to a variety of allylic trifluoromethyl thioethers. The copper(I)-catalyzed trifluoromethylthiolation of propargylic chlorides was also investigated. A plausible mechanism that involves an allylcopper(III) intermediate is proposed.

An efficient and practical approach to α-trifluoromethylthio-substituted ketones was developed. The trifluoromethylthiolation of (bpy)Cu(SCF₃) (bpy = 2,2′-bipyridyl) with various α-bromo ketones afforded the desired α-trifluoromethylthio-substituted ketones in good yields. The reaction tolerates more functionally than previously reported methods and demonstrates efficient scalability and practicality.

The development of new strategies for synthesis of trifluoromethylthiolate compounds is of considerable importance in pharmaceuticals, agrochemicals, and advanced materials. Accordingly, currently much attention is being devoted to the development of effective methods and reagents for their synthesis. In contrast, considerably less effort has been afforded to the development of preparing CSeCF₃ bonds. Herein we report a concise route to synthesize a family of copper(I) trifluoromethylselenolate reagents by the reaction of CuI with the Ruppert’s reagent (Me₃SiCF₃), KF, and elemental selenium in the presence of dinitrogen ligands in CH₃CN at room temperature. The reagent [Cu(bpy)(SeCF₃)]₂ was proven to be air-stable and highly efficient for nucleophilic trifluoromethylthselenolation of a broad range of (hetero)aryl halides and alkyl halides. This method represents a powerful protocol for the construction trifluoromethylselenolate compounds.

A facile preparation of allylic trifluoromethyl thioethers was achieved by using a copper reagent. The reaction of (bpy)Cu(SCF₃) with various allylic bromides afforded the desired trifluoromethylthiolation products in good to excellent yields with high stereo- and regioselectivity. Common functional groups such as alkyl, alkoxy, trifluoromethyl, nitro, halides and geranyl are well tolerated.