Synthesis and Characterization of Fluorinated Hypervalent Tellurium Derivatives

Abstract

The synthesis of tellurium derivatives bearing fluorinated groups, similar in structure to their hypervalent iodine congeners, is reported. Thus, a series of CF 3 , CF 2 H, and C 6 F 5 aryltellurium(II) species bearing various functional groups interacting with the Te atom was obtained. The installation of the various fluorinated groups relies on the use of the corresponding trimethylsilyl precursors. The hypervalent nature of the products is discussed on the basis of their NMR spectroscopic and X-ray crystallographic characterization.

Supramolecular Aggregation of Perfluoroorganyl Iodane Reagents in the Solid State and in Solution

“…[46] The iodine atom in 9 displays no defined tertiary bonding interactions with any donor moieties, most likely because of efficient shielding of the iodine center by the bulky C 6 F 5 group. The crystallographic details for the acid adducts [ 6 ]·H 2 O. In this compound, the proton is located at the exposed O atom of the carboxyl moiety.…”

“…1 [1] [3] 226.7(3) 211.8 (2) 169.78 (7) 299.8(1) 5 [6] 229.9(2) 211. 8 As anticipated, the crystal structures of 1-9 go beyond simple monomeric molecules, and intermolecular I···O contacts far shorter than the sum of the van der Waals radii of I and O (350 pm) [17] were found in all compounds.…”

“…Furthermore, we have shown that acid‐reagent analogs containing a hypervalent atom other than iodine are accessible, specifically those with a tellurium atom. This reagent class is compatible with new fluorinated substituents such as CHF 2 and C 6 F 5 . However, knowledge of the preparation, molecular structures, and reactivity of iodane reagents with “simple” perfluoroalkyl chains is still very limited.…”

“…This reagent class is compatible with new fluorinated substituents such as CHF 2 and C 6 F 5 . [6] However, knowledge of the preparation, molecular structures, and reactivity of iodane reagents with "simple" perfluoroalkyl chains is still very limited. Acid and alcohol reagents with the C 2 F 5 group (2 and 5) have been briefly mentioned in the literature, [7,8] as well as an acid reagent with the n-C 3 F 7 group (3).…”

“…[12] The C 2 F 5 (2) [7] and n-C 3 F 7 acid reagents (3) [9] have been prepared from the corresponding acetoxyiodane (Scheme 1b). A key precursor for the preparation of alcohol reagents with various perfluoroalkyl groups (4)(5)(6)(7)(8) is the corresponding fluoroiodane. As this compound is more stable than the acid-reagent analog, it can be isolated and used for further derivatization.…”