The reaction of benzotrihalides and benzal halides with magnesium. Synthetic and mechanistic studies

Grignard reagent formation via C–F bond activation: a centenary perspective

“…However, it is known that Grignard reagents formed from trifluoromethylphenyl halides can undergo explosive decomposition (Scheme 10). 91,92 In fact, large-scale preparation of these reagents has caused serious accidents in the past, including a loss of life and destruction of a factory. The exact origin of this reactivity, unique to the CF 3 -substituted arenes, remains elusive.…”

Synthesis of Organometallic Compounds in Flow

“…The Grignard reagent solution could then be used either in batch or directly by mixing the outcome of the column with different electrophiles. It is worth noting that this method was used to prepare potentially explosive (trifluoromethyl)phenylmagnesium bromides in a safe and reproducible manner …”

“…It is worth noting that this method was used to prepare potentially explosive (trifluoromethyl)phenylmagnesium bromides in a safe and reproducible manner. [63,64]…”

Exploration of Mechanochemical Activation in Solid-State Fluoro-Grignard Reactions

“…Despite the somewhat uncertain prospects for the clean mechanochemical generation of an RMgX species, we were interested in investigating Grignard systems that do not usually work well-if at all-in solution, specifically fluoro-Grignards ('RMgF'). The C-F bond is roughly 38 kcal mol −1 stronger than the next strongest carbon-halogen bond (C-Cl) [28], and the attempted reaction of elemental magnesium with an organofluorine in solution is usually unsuccessful [29]. Exploration of this issue dates back a century, beginning with the work of Swarts in 1921 [30], and an array of methods has been used in efforts to provide a more reactive magnesium source [31]; some of the early strategies have been reviewed [32].…”

“…We report here the use of the mechanochemical activation of Mg with fluorinated naphthalenes, in which it is clear that C-F bond activation has occurred, although there are still practical issues that must be overcome prior to more general development of the method. There have been cautions raised about the potentially explosive nature of fluorinated Grignards [29], but no such difficulties were encountered with the monofluoro organics used here.…”