N-HALOGENO COMPOUNDS .13. N-FLUOROQUINUCLIDINIUM SALTS - SYNTHESIS AND USE AS ELECTROPHILIC FLUORINATING AGENTS

A convenient one-pot method has been developed for the preparation of the easily handled electrophilic fluorinating agent N-fluoroquinuclidinium triflate from quinuclidine, lithium triflate and fluorine. The corresponding trifluroacetate, heptafluoro-n-butyrate and tetrafluoroborate salts were procured in a two-step fashion by adding the appropriate sodium salts to acetonitrile solutions of N-fluoroquinuclidium fluoride. Site-specific fluorination of phenylmagnesium bromide (to PhF), diethyl sodio(phenyl)malonate [to PhCF(CO2Et)2], 2-nitropropan-2-yl-lithium [to Me2CFNO2], 1-morpholinocyclohexene [to activated CH2(CH2)3CHFC = O], phenol (to 2- and 4-FC6H4OH + 1,4-F2C6H3OH) and sodium benzenesulphinate (to PhSO2F) was achieved using these new N-fluoroquinuclidinium salts.