Site-Selective Sonogashira Reactions of 1,4-Dibromo-2-(trifluoromethyl)benzene: Synthesis and Properties of Fluorinated Alkynylbenzenes

Practical tetrafluoroethylene fragment installation through a coupling reaction of (1,1,2,2-tetrafluorobut-3-en-1-yl)zinc bromide with various electrophiles

(1,1,2,2-Tetrafluorobut-3-en-1-yl)zinc bromide was prepared by insertion of the zinc–silver couple into the CF₂–Br bond of commercially available 4-bromo-3,3,4,4-tetrafluorobut-1-ene in DMF at 0 °C for 0.5 h, The resultant polyfluorinated zinc reagent was found to be thermally stable at ambient temperature and storable for at least 1.5 years in the refrigerator. This CF₂CF₂-containing organozinc reagent could be easily transmetallated to copper species, which underwent cross-coupling reactions with various aromatic iodides or acyl chlorides to produce a broad range of CF₂CF₂-containing organic molecules in good-to-excellent yields. Therefore, the zinc reagent could become a new and practical synthetic tool for producing functional molecules with a CF₂CF₂ fragment.

Synthesis of functionalised fluorinated pyridine derivatives by site-selective Suzuki-Miyaura cross-coupling reactions of halogenated pyridines

The Suzuki-Miyaura reaction of 2,6-dichloro-3-(trifluoromethyl)pyridine with 1 equiv of arylboronic acids resulted in site-selective formation of 2-aryl-6-chloro-3-(trifluoromethyl)pyridine. Due to electronic reasons, the reaction takes place at the sterically more hindered position. The selectivity was rationalised by DFT calculations. The one-pot reaction with two different arylboronic acids afforded 2,6-diaryl-3-(trifluoromethyl)pyridine containing two different aryl substituents. The reactions proceeded smoothly in the absence of phosphine ligands. In addition, Suzuki-Miyaura reactions of 2,6-dichloro-4-(trifluoromethyl)pyridine with one or two equivalents of arylboronic acids were carried out.

Nanoscale functionalization of surfaces by graft-through Sonogashira polymerization

“Graft-through” Sonogashira polymerization has been performed on functionalized self-assembled monolayer.