Preparation of Aromatic Fluorine Compounds from Diazonium Fluoborates

Abstract

An excellent method for the introduction of fluorine into the aromatic nucleus, described by Balz and Schiemann, has been extensively extended. The method involves two steps, first, the preparation and solution of a dry diazonium fluoborate, and second, the controlled decomposition of this salt by heat to yield an aromatic fluoride, nitrogen, and boron trifluoride. This phenomenon which makes possible, the Schiemann reaction is the remarkable stability of the dry diazonium borofluoride. The overall yields are satisfactory and no special apparatus is necessary. The reaction may be carried out on a wide variety of amines. The effect of the Schiemann reaction on other groups present in the ring is discussed in detail.

Copper-free Sandmeyer cyanation of arenediazonium o-benzenedisulfonimides

“…4-Methoxybenzenediazonium tetrafluoroborate was prepared as reported in the literature. 12 Structures and purity of aryl nitriles 3 were confirmed by their spectral (NMR, MS, IR) and physical data, substantially identical to those of commercial (Sigma-Aldrich) samples. Yields of pure (GC, GC-MS, TLC and NMR) isolated aryl cyanides 3 are collected in Table 2; their physical data, spectroscopic data and NMR spectra are reported in ESI.…”

How do arenediazonium salts behave in deep eutectic solvents? A combined experimental and computational approach

“…Arenediazonium tetrafluoroborates were prepared as reported in the literature. [61] Structures and purity of arenes 2 were confirmed by their spectral data (NMR, MS), substantially identical to those of commercial samples. Yields of pure (GC-FID, GC-MS, TLC and NMR) and isolate 2 are collected in Table 3; their NMR spectra are reported in Supporting Informations.…”

Synthesis of New C- and N-β-d-Glucopyranosyl Derivatives of Imidazole, 1,2,3-Triazole and Tetrazole, and Their Evaluation as Inhibitors of Glycogen Phosphorylase

“…Although the tautomerism of the tetrazole moiety could have facilitated the formation of regioisomers, only 10a was obtained in excellent yield as it was claimed in the cited paper. By modifying a literature procedure [ 54 ], compound 10a was also prepared, albeit in lower yield, from tosylhydrazone 12 [ 55 , 56 ] and benzenediazonium tetrafluoroborate [ 57 , 58 ] (conditions c ). For the methylation of 9 a method [ 59 ] applied for the synthesis of C -glycofuranosyl tetrazoles was adapted.…”

“…Organic solutions were dried over anhydrous MgSO 4 and concentrated in vacuo at 40–50 °C (water bath). Alkynes 1 [ 45 ] and 3 [ 51 ], tetrazole 9 [ 49 ], tosylhydrazone 12 [ 55 , 56 ], 5-phenyltetrazole [ 62 ], 5-methyltetrazole [ 62 ], and benzenediazonium tetrafluoroborate [ 57 , 58 ] were prepared according to literature procedures.…”