Onium ions. 29. Cyanation and nitration of toluene with cyanamide and nitramide through intermediate cyano- and nitrodiazonium ions. Attempted fluorination of aromatics with fluorodiazonium ion

Abstract

Cyanation and Nitration of Toluene with Cyanamide and Nitramide through Intermediate Cyano-and Nitrodiazonium Ions. Attempted Fluorination of Aromatics with Fluorodiazonium Ton1 Summary: Toluene is cyanated and nitrated with cyanoand nitrodiazonium ion, generated via in situ diazotization of cyanamide and nitramide, respectively, with NO+BF4~. Attempted fluorination with fluorodiazonium ion, prepared from cis-difluorodiazene and arsenic pentafluoride, gave only trace amounts of fluoroaromatics.

Positive Ion Chemistry of Elemental Fluorine

“…The F 2 •+ reaction with N 2 is characterized by a rate constant of 8.6 × 10 -10 cm 3 molecule -1 s -1 , which corresponds to a unit efficiency, as expected from the high exothermicity of both the ET (reaction 1a, M = N 2 ) and FT (reaction 1b) reaction channels. The fluorodiazonium ion, N 2 F + , is a well-known species which can be prepared in acid media and can be isolated as a salt . By contrast, the formation of N 2 F + in the gas phase has been reported to be a minor channel in the CI of NF 3 /HN 3 gaseous mixtures, where it derived from the dissociation of HF from intermediate F 2 N−NH + ions 21e.…”

“…The fluorodiazonium ion, N 2 F + , is a well-known species which can be prepared in acid media and can be isolated as a salt . By contrast, the formation of N 2 F + in the gas phase has been reported to be a minor channel in the CI of NF 3 /HN 3 gaseous mixtures, where it derived from the dissociation of HF from intermediate F 2 N−NH + ions 21e. At present, only the F 2 •+ reaction with N 2 provides an efficient route yielding abundant N 2 F + ions by an ion−molecule reaction occurring in the ICR cell.…”

“…At present, only the F 2 •+ reaction with N 2 provides an efficient route yielding abundant N 2 F + ions by an ion−molecule reaction occurring in the ICR cell. The enthalpy change of this reaction (reaction 1b, M = N 2 ) is estimated to be −53 kcal mol -1 , using the Δ H ° f (N 2 F + ) value of 291 kcal mol -1 , recently evaluated by ab initio MO calculations 21e…”

1-Fluoro-2,4,6-trichloro-1,3,5-triazinium tetrafluoroborate: synthesis, characterization, and ability to effect electrophilic aromatic substitution

“…In this respect, while 1 falls well short of the inorganic N-F reagents NF 4 þ X À (X À ¼ BF 4 À , AsF 6 À , SbF 6 À ) and FN 2 þ AsF 6 À , which electrophilically fluorinate nitrobenzene in anhydrous HF at À78 8C [8,9] and methane in HF or pyridine-HF at room temperature [10], it appears to be at least as reactive as N-fluorobis(trifluoromethylsulfonyl)imide (3) and N-fluoropentachloropyridinium triflate (4), hitherto judged to be the most powerful F þ delivery agents of the organic N-F class [11]. These two reagents (3, 4) fluorinate benzene and its activated derivative C 6 and 2FC 6 H 4 NO 2 ) Since a swift exothermic reaction occurs between methoxybenzene and 1 at room temperature, solutions containing these reactants in CD 3 CN or CH 3 NO 2 were prepared at À20 8C (this precaution does not appear to have been necessary in the cases of fluorination with 3 [12] or 4 [13]).…”

Nitrosation of Cyanamide: Preparation and Properties of the Elusive E‐ and Z‐N'‐Cyanodiazohydroxides

“…He drew conclusions about the tautomeric structure of cyanamide. Besides MO calculations suggesting stability of cyanodiazonium[2a] and its experimental observation in the gas phase formed from cyanamide and NF 3 ,[2b] Olah reported a reaction between cyanamide and nitrosyl tetrafluorobrate. He postulated cyanodiazonium tetrafluoroborate as an unstable intermediate that reacts with toluene under N 2 abstraction to form a mixture of isomeric tolunitriles.…”