N-halogeno compounds. Part 9. N-Fluoroquinuclidinium fluoride—a new electrophilic fluorinating agent

Abstract

N-Fluoroquinuclidinium fluoride, prepared in high yield by treatment of a cold, dilute solution of quinuclidine in trichlorofluoromethane with fluorine at low pressure in a specially designed, virtually all glass vacuum system, acts as a site-selective electrophilic fluorinating agent towards carbanionic substrates [PhCNa(CO₂Et)₂→ PhCF(CO₂Et)₂; Me₂CLiNO₂→ Me₂CFNO₂; RMgX → RF (R = Ph, X = Br; R = c-C₆H₁₁, X = Cl); [graphic omitted]H₂→ [graphic omitted]HF; PhSiCl₃/F^–(in situ)→ PhF].