Efficient Synthesis of Secondary Alkyl Fluorides via Suzuki Cross-Coupling Reaction of 1‑Halo-1-fluoroalkanes

Organofluorine compounds have found extensive applications in various areas of science. Consequently, the development of new efficient and selective methods for their synthesis is an important goal in organic chemistry. Here, we present the first Suzuki cross-coupling reaction which utilizes dihalo compounds for the preparation of secondary alkyl fluorides. Namely, an unprecedented use of simple 1-halo-1-fluoroalkanes as electrophiles in C_sp³-C_sp³ and C_sp³-C_sp² cross-couplings allows for the formal site-selective incorporation of F-group in the alkyl chain with no adjacent activating functional groups. Highly effective approach to the electrophilic substrates, 1-halo-1-fluoroalkanes, via iododecarboxylation of the corresponding α-fluorocarboxylic acids is also presented. The conceptually new route to organofluorides was used for the facile preparation of biomedically valuable compounds. In addition, we demonstrated that an asymmetric version of the developed reaction for the stereoconvergent synthesis of chiral secondary alkyl fluorides is feasible

Aliphatic C–H Bond Iodination by a <i>N</i>‑Iodoamide and Isolation of an Elusive <i>N</i>‑Amidyl Radical

Contrary to C–H chlorination and bromination, the direct iodination of alkanes represents a great challenge. We reveal a new <i>N</i>-iodoamide that is capable of a direct and efficient C–H bond iodination of various cyclic and acyclic alkanes providing iodoalkanes in good yields. This is the first use of <i>N</i>-iodoamide for C–H bond iodination. The method also works well for benzylic C–H bonds, thereby constituting the missing version of the Wohl–Ziegler iodination reaction. Mechanistic details were elucidated by DFT computations, and the N-centered radical derived from the used <i>N</i>-iodoamide, which is the key intermediate in this process, was matrix-isolated in a solid argon matrix and characterized by UV–vis as well as IR spectroscopy