Wolfgang Appel

Utilisation of ammonium and phosphonium perfluorocyclobutane ylides as fluoride anion source

Ammonium- and phosphoniumperfluorocyclobutane ylides 1 and 2, prepared from perfluorocyclobutene and tertiary amines or phosphines can be used as a masked fluoride anion source. These properties have been demonstrated in several reactions. Ylides 1 and 2 cleave C-Si or O-Si bonds, cause dimerisation of fluoroolefins or react with acid chlorides or activated aromatic compounds under halogen exchange.

New method of preparation of fluoro compounds via utilisation of ammonium and phosphonium perfluorocyclobutane ylides as fluorination reagents

Ammonium- and phosphoniumperfluorocyclobutane ylides (7–11), easily prepared from perfluorocyclobutene (1) and tertiary amines (2–4) or phosphines (5,6), smoothly react with primary or secondary alcohols (12–18) and carboxylic acids (19,20) with formation of alkyl fluorides (21–26) or acyl fluorides (27,28), respectively. A mechanism for the reaction is proposed.

Synthesis and properties of fluorinated oxo- and thioxo-(p-dimethylaminopyridinium)cyclobetaines

Abstract The interaction of 1,2-dichloroperfluorocycloolefins with p-dimethylaminopyridine (DMAP) leads to the formation of 1,2-bis[4-dimethylamino)pyridinium-1-yl]fluorocycloalkene dichlorides, which can be transformed to the corresponding dioxo-, oxothioxo- and dithioxocyclofluoropyridinium betaines. The properties of the newly synthesized compounds have been investigated. All new compounds were characterized by NMR spectroscopy and elemental analysis.