Regioselective oxidative C–H heptafluoroisopropylation of heteroarenes with heptafluoroisopropyl silver

Abstract

While the CF(CF3)2-containing arenes are prevalent in pharmaceuticals and agrichemicals, the CF(CF3)2-containing heteroarenes remain largely underexplored. Herein, we disclose the first oxidative C–H heptafluoroisopropylation of heteroarenes using AgCF(CF3)2 as the...

Review and Theoretical Analysis of Fluorinated Radicals in Direct CAr−H Functionalization of (Hetero)arenes

“…AgCF 3 ( 49 ) generated in situ from a mixture of HCF 3 , or Ruppert‐Prakash's reagent ( 50 ) in presence of a silver salt, was also identified as an efficient source of ⋅CF 3 radical ( G ) [208] . Similarly, the chemical oxidation ( G ) of the silver salt 51 produced from gaseous hexafluoropropylene and AgF in acetonitrile, was reported for the generation of ⋅CF(CF 3 ) 2 radicals by the Qing group [209] . The silver salt 52 was also reported to undergo an oxidative decarboxylation photocatalyzed by anastase TiO 2 powder ( I ) to liberate a ⋅CF 3 radical [210] .…”

“…[208] Similarly, the chemical oxidation (G) of the silver salt 51 produced from gaseous hexafluoropropylene and AgF in acetonitrile, was reported for the generation of * CF(CF 3 ) 2 radicals by the Qing group. [209] The silver salt 52 was also reported to undergo an oxidative decarboxylation photocatalyzed by anastase TiO 2 powder (I) to liberate a * CF 3 radical. [210] Besides, Nebra and Mézailles have disclosed the synthesis of a nickel complex Ni IV (CF 3 ) 2 (49) capable of slowly liberating * CF 3 radicals at room temperature through NiÀ CF 3 bond homolysis (N).…”

Pentafluorocyclopropanation of (Hetero)arenes Using Sulfonium Salts: Applications in Late‐Stage Functionalization

“…Cumulative X-ray diffraction data evidence that the latter, in the absence of distortions due to steric hindrance, preferentially brings the benzylic CÀ F bond as close to coplanarity with the heterocycle plane as the allylic-strain permits. [29] To better understand the unique conformational preference of the PFCP units, the C1À C4 bond rotational profiles of 2-phenylheptafluoroisopropane (9), 2-phenyl-2-fluoroisopropane (10), phenylcyclopropane (11) and phenylpentafluorocyclopropane (12) were explored computationally at the B3LYPÀ D3(BJ)/def2-TZVP level of theory, [30] with the F1/H1À C1À C4À C5 dihedral being used as scanning variable. In close agreement with the crystallographic data available, the absolute energetic minimum is calculated for the rotamer of 9, in which the benzylic CÀ F bond is coplanar with the phenyl ring (Φ = 0°, 180°).…”

Recent Uses of Photogenerated Oxygen-Centered Radicals in Intermolecular C–O Bond Formation

“…In 2021, Qing and co-workers disclosed the preparation of a library of new N-OCF(CF 3 ) 2 reagents for heptafluoroisopropoxylation of organic molecules. 24 Among them, the benzotiazole-based reagent 29 displayed the highest reactivity for the photoredox-catalyzed heptafluoroiospropoxylation of arenes and heteroarenes (Scheme 13 ). Under similar reaction conditions to those used with Ngai’s OCF 3 and OCF 2 H benzotriazole-based reagents, a wide range of arenes and heteroarenes 30 , including thiophenes, pyrazoles, imidazoles, thiazoles, 1,2,3-triazoles and quinoxalines, were smoothly converted into the corresponding OCF(CF 3 ) 2 adducts 31 in moderate to high yields.…”