Isolable Pyridinium Trifluoromethoxide Salt for Nucleophilic Trifluoromethoxylation.

An isolable pyridinium trifluoromethoxide salt is prepared from the reaction of 4-dimethylaminopyridine with the commercially available liquid 2,4-dinitro(trifluoromethoxy)benzene. The salt is an effective trifluoromethoxide source for S2 reactions to form trifluoromethyl ethers.

Connecting Organometallic Ni(III) and Ni(IV): Reactions of Carbon-Centered Radicals with High-Valent Organonickel Complexes.

This paper describes the one-electron interconversions of isolable Ni and Ni complexes through their reactions with carbon-centered radicals (R•). First, model Ni complexes are shown to react with alkyl and aryl radicals to afford Ni products. Preliminary mechanistic studies implicate a pathway involving direct addition of a carbon-centered radical to the Ni center.

Palladium-Catalyzed Difluoromethylation of Aryl Chlorides and Bromides with TMSCFH.

A palladium-catalyzed cross-coupling of aryl chlorides/bromides with TMSCFH is described. Two different catalysts, Pd(dba)/BrettPhos and Pd(P Bu), are demonstrated and provide a variety of difluoromethylated arenes in good yields.

Room Temperature Deoxyfluorination of Benzaldehydes and α-Ketoesters with Sulfuryl Fluoride and Tetramethylammonium Fluoride.

A method for the room temperature deoxyfluorination of benzaldehydes and α-ketoesters using sulfuryl fluoride and MeNF is described. A large scope of aryl and heteroaryl substrates is demonstrated, and this method compares favorably to other common deoxyfluorination methods for many substrates.

Stoichiometric and Catalytic Aryl-Perfluoroalkyl Coupling at Tri-tert-butylphosphine Palladium(II) Complexes.

This Communication describes studies of Ph-R (R = CF or CFCF) coupling at Pd complexes of general structure (PBu)Pd(Ph)(R). The CF analogue participates in fast Ph-CF coupling (<5 min at 80 °C). However, the formation of side products limits the yield of this transformation as well as its translation to catalysis.

Palladium-Catalyzed Intra- and Intermolecular C-H Arylation Using Mesylates: Synthetic Scope and Mechanistic Studies.

This paper describes the development of Pd-catalyzed inter- and intramolecular direct arylation using mesylates. Furthermore, a sequential mesylation/arylation protocol using phenols as substrates is described. These transformations are general with respect to the electronics of the C-H substrates and allow for the synthesis of diverse heterocyclic motifs in good yields.