Transition‐Metal‐Free Electrophilic Fluoroalkanesulfinylation of Electron‐Rich (Het)Arenes with Fluoroalkyl Heteroaryl Sulfones via C(Het)−S and S=O Bond Cleavage

Lewis Base-Catalyzed Trifluoromethylsulfinylation of Allylic Alcohols: Stability-Oriented Divergent Synthesis

A novel strategy is demonstrated for Lewis base-activated trifluoromethylsulfinylation of allylic alcohols. Controllable synthesis of structurally varied allylic trifluoromethanesulfones via sigmatropic rearrangements was performed, and trifluoromethanesulfinate esters were achieved. This metal-free, catalytic divergent transformation features good functional group tolerance and late-stage modification of bioactive molecules. Mechanistic studies suggested that Lewis bases interact with N-(trifluoromethylsulfinyl)phthalimide to generate an ion pair adduct followed by O-trifluoromethylsulfinylation with allylic alcohols.

β-Trifluorosulfinylesters: tuneable reagents for switchable trifluoromethylsulfinylation and C–H trifluoromethylthiolation

β-Trifluorosulfinylesters, a family of novel reagents from commercially available starting materials for direct trifluoromethylthiolation and trifluoromethylsulfinylation were developed.

Visible-light-promoted S-trifluoromethylation of thiophenols with trifluoromethyl phenyl sulfone

Trifluoromethyl phenyl sulfone is traditionally a nucleophilic trifluoromethylating agent. Herein, we report the first example of the use of trifluoromethyl phenyl sulfone as a trifluoromethyl radical precursor. Arylthiolate anions can form electron donor-acceptor (EDA) complexes with trifluoromethyl phenyl sulfone, which can undergo an intramolecular single electron transfer (SET) reaction under visible light irradiation, thus realizing the S-trifluoromethylation of thiophenols under photoredox catalyst-free conditions. Similar S-perfluoroethylation and S-perfluoro-iso-propylation of thiophenols are also achieved using the corresponding perfluoroalkyl phenyl sulfones.

Synthesis of N-Trifluoromethanesulfinyl Ketimines by Cascade Trifluoromethylthiolation/Rearrangement of Ketoximes

A new and efficient cascade electrophilic trifluoromethylthiolation/radical rearrangement reaction of ketoximes is reported using N-trifluoromethylthio-dibenzenesulfonimide as the SCF₃ source without any additives. This simple one-pot reaction provides the corresponding N-trifluoromethanesulfinyl ketimine products in good yields with high E selectivity under mild reaction conditions.

Photoredox Generation of Sulfonyl Radicals and Coupling with Electron Deficient Olefins

Various sulfone tetrazoles were activated via iridium photoredox catalysis in the presence of DMAP to give dialkyl sulfones. The presumed sulfone radical intermediates were trapped by a range of electron-deficient olefins in generally good to excellent yields.

Novel usage of 2-BTSO2CF2H for metal-free electrophilic difluoroalkanethiolation of indoles

2-BTSO₂CF₂H was used as an efficient electrophilic –SCF₂H synthon for the first time for the metal-free electrophilic difluoromethylthiolation of indoles.