Relative Electrophilic Fluorinating Power as Assayed by Competitive Catalytic Halogenation Reactions.

Abstract

Catalytic fluorination/chlorination competition experiments of b-keto ester 5 were used to assess the relative fluorinating activity of various electrophilic NÀF reagents (containing an NÀF bond). Thus, in the halogenation reactions catalyzed by the [Ti(TADDOLato)] complex 1 ( bis(acetonitrile)dichloro[(4R,5R)-2,2-dimethyl-a,a,a',a'-tetra(naphthalen-1-yl)-1,3-dioxolane-4,5-dimethanolato(2 À)-kO,kO']titanium), the activity range of a series of commercially available reagents spans more than two orders of magnitude..2]octane bis(tetrafluoroborate); 9; also called F-TEDA; TEDA triethylenediamine) reacts more than 100 times faster than 1-fluoropyridinium tetrafluoroborate.