Palladium-catalyzed C–H trifluoromethylselenolation of arenes with [Me₄N][SeCF₃] and an oxidant

Abstract

Trifluoromethylselenolation of arenes with [Me4N][SeCF3] in the presence of an oxidant through Pd-catalyzed C(sp2)-H activation under the assistance of a directing group is established for the first time. The reaction...

Photoinduced Trifluoromethylselenolation of Aryl Halides with [Me4N][SeCF3]

“…The 19 F NMR analysis of the reaction mixtures of 1a , 2 , and DABCO in DMAc under the standard conditions at 0.5, 1, 2, 4, and 8 h disclosed that [Me 4 N]­[SeCF 3 ] was gradually consumed with a continuous increase of the product ( 3a ) (see the SI). These observations implicated a relatively slow conversion of [Me 4 N]­[SeCF 3 ] in comparison with those in the previous trifluoromethylselenolations under oxidative conditions. ,,, …”

“…The recent studies on CF 3 Se-containing amino acids and their derivatives, CF 3 Se bioisosteres of Riluzole and Pretomanid, CF 3 Se derivatives of nonsteroidal anti-inflammatory drugs, and insecticidal phenylpyrazole derivatives bearing a SeCF 3 moiety have verified the trifluoromethylselenolated compounds with improved cytotoxicity or potency, which demonstrated the great potential of SeCF 3 functionality in life sciences . Consequently, much effort has been made in the construction of C–SeCF 3 bonds by developing different trifluoromethylselenolation reagents and methodologies. , Among the known SeCF 3 sources (e.g., MSeCF 3 (M = 1/2Hg, Cu, Ag, Me 4 N), [(bpy)­CuSeCF 3 ] 2 , ClSeCF 3 , and TsSeCF 3 ), tetramethylammonium trifluoromethylselenate ([Me 4 N]­[SeCF 3 ]) has been considered to be the more versatile reagent because it has obvious advantages, such as good thermal stability, nonvolatility, easy preparation and handling, no involvement of metals and ligands, and rich chemistry, which have contributed heavily to the preparation of diverse SeCF 3 -containing molecules. − Thanks to the nucleophilicity and easy oxidation of [Me 4 N]­[SeCF 3 ], a variety of transition-metal-catalyzed, transition-metal-free, oxidative, and/or photoredox trifluoromethylselenolation reactions have been developed. − Even so, the use of [Me 4 N]­[SeCF 3 ] salt in modern and ecofriendly trifluoromethylselenolations is still immature. In this content, the search for efficient and environmentally benign methods for the incorporation of the SeCF 3 group into extensive organic scaffolds with [Me 4 N]­[SeCF 3 ] has attracted increasing attention, which would undoubtedly benefit the facile synthesis and application of the SeCF 3 -containing molecules.…”

Design, Synthesis, and Biological Activities of Novel Phenylpyrazole Derivatives Containing a Trifluoromethylselenyl Moiety

“…All melting points were obtained with a Buchi Melting Point B540 and are uncorrected. 1 H NMR (400 MHz) and 13 C NMR (101 MHz) spectra were obtained on a Bruker AM-400 spectrometer with CDCl 3 or DMSO-d 6 as the solvent and tetramethylsilane (TMS) as the internal standard. Chemical shifts were reported in units (ppm) by assigning TMS resonance in the 1 H NMR spectra as 0.00 ppm (CDCl 3 , δ = 7.26 ppm; DMSO, δ = 2.54 ppm).…”

“…Data were reported as follows: chemical shift, multiplicity (s = singlet, d = doublet, t = triplet, and m = multiplet), coupling constant (J values) in Hz, and integration. Chemical shifts for 13 C NMR spectra were recorded in ppm from tetramethylsilane using the central peak of CDCl 3 (δ = 77.0 ppm) and DMSO-d 6 (δ = 40.45 ppm) as the internal standard. High-resolution mass spectrometry (HRMS) was recorded under an electron impact (70 eV) condition using a MicroMass GCT CA 055 instrument.…”

“…Fluorine atoms and fluorine-containing groups are crucial substituents in the advancing pharmaceutical, agrochemical, and material sciences exploration . Among the known fluoroalkyl groups, the trifluoromethylselenyl functionality (SeCF 3 ) has been recognized as a promising structural motif in drug design and development because it has useful electronic characteristics (Hammett constants σ p = 0.45, σ m = 0.44), and its valuable lipophilicity parameter (Hansch–Leo parameter π R = 1.61) is evaluated to be larger than those of OCF 3 (π R = 1.04) and SCF 3 (π R = 1.44) groups . Such features of SeCF 3 can not only appropriately increase the cell permeability of the molecule but also effectively improve molecular cell metabolism and biological activity .…”