Trifluoromethylselenolation of Aryldiazonium Salts: A Mild and Convenient Copper‐Catalyzed Procedure for the Introduction of the SeCF₃Group

Abstract

The straightforward introduction of the trifluoromethylseleno group into aromatic and heteroaromatic compounds is accomplished by the utilization of readily available aryldiazonium tetrafluoroborates, potassium selenocyanate, and Ruppert-Prakash reagent. The reaction tolerates a wide range of aromatic and heteroaromatic diazonium salts and is also amenable to the synthesis of pentafluoroethyl selenoethers. Furthermore, the methodology can be applied directly starting from anilines.

Visible‐Light‐Mediated Metal‐Free Synthesis of Trifluoromethylselenolated Arenes

“…[7] As part of our continuing interest in discovering and developing new synthetic methods,weturned our attention to studying the formation of C(sp 2 ) À SeCF 3 bonds using the above-mentioned compound. Regarding the state of the art, the use of nucleophilic ammonium trifluoromethylselenide is the most studied approach in conjunction with aryl halides under nickel [8] or palladium [9] catalysis.A rene diazonium salts [10] and arylboronic acids [7b, 11] have also been used as starting materials.F inally,d iscrete s-bonded copper-SeCF 3 complexes have been employed in stoichiometric fashion for the trifluoromethylselenolation of aryl iodides and activated bromides. [12] From ac onceptual standpoint, we wondered whether organic photoredox catalysis [13] might be used to leverage the orthogonality of transition-metal-catalyzed C(sp 2 ) À SeCF 3 bond formation under mild reaction conditions.…”

Divergent Reactivity of a Dinuclear (NHC)Nickel(I) Catalyst versus Nickel(0) Enables Chemoselective Trifluoromethylselenolation

“…[11] Consequently,t here have been numerous activities in devising synthetic methods to access this compound class. [12] Thedirect catalytic incorporation of the SeCF 3 moiety is of particular interest as it may be used for late-stage manipulations of molecules.T he latter concept has,h owever, rarely been realized; [13] it has been accomplished for aryl diazonium salts under Cu catalysis, [14] and ac oupling of aryl iodides with (Me 4 N)SeCF 3 catalyzed by adinuclear Pd I complex has been developed by our group. [6c] We started our investigations with assessing as to whether Ni 0 (cod) 2 in combination with the NHC ligand 1,3-bis(2,6diisopropylphenyl)imidazolin-2-ylidene (SIPr) could trigger the trifluoromethylselenolation of aryl halides.I nt he pres- ence of this catalyst and ligand, 4-iodoanisole (1)w as converted into the corresponding ArSeCF 3 product in 59 % yield ( Figure 2).…”

Synthetic Approaches to Trifluoromethylselenolated Compounds

“…The group of Rueping reported a one‐pot two‐step procedure for the trifluoromethylselenolation of (hetero)aromatic diazonium salts (Scheme ). The first step constituted a selenocyanation of the diazonium salt in the presence of two copper salts, cuprous chloride and cupric chloride (both present in 10 mol %) in conjunction with 1,10‐phenathroline as a ligand (10 mol %).…”

“…The group of Rueping [51] reported ao ne-pot two-step procedure for the trifluoromethylselenolation of (hetero)aromatic diazonium salts (Scheme 35). The first step constituted as eleno-Scheme29.…”