In June of 1886 (26th to be precise) the French chemist Henri Mossian passed an electric current through a solution of KHF2 in anhydrous HF and became the first person to generate fluorine. Rather him than me. But he did, quite rightly, win a Nobel prize for his efforts in 1905. Since then, methods to
Tag: fluorine
If Nature could re-write her proteinogenic amino acid instruction manual I’m fairly sure that a piperidine ring would feature in there somewhere. Perhaps in the spirit of less is more the pyrrolidine ring won out. Not so for human synthetic engineers- the piperidine ring is ubiquitous in pharmaceuticals, agrochemicals and advanced materials and is the
Deoxyfluorination remains amongst the most frequently used method for preparing alkyl fluoro compounds.1 The reaction typically involves activation of a leaving group followed by SN2 (but occasionally SN1) reaction with fluoride ion. This is usually accompanied with significant elimination side-reactions and can frequently be low yielding. The original deoxyfluorination reagents such as DAST (diethylaminosulfur-trifluoride) and
The use of fluorine and fluorine-containing functional groups in medicinal chemistry, agrochemicals and advanced materials has grown over the past fifty years.1 Not surprisingly this increase in utility tracks with notable developments and refinements in safe and accessible synthetic methodology, both on the discovery and development front and in subsequent manufacturing. A recent example that caught
Aryl- and heteroaryl- diazonium tetrafluoroborate salts, prepared by diazotization of an aniline in the presence of HBF4, are unique in that in many cases they are sufficiently stable to isolate. Thermal decomposition of these salts at elevated temperatures results in fluoro-dediazoniation and formation of the corresponding aryl or heteroaryl fluoride- the Balz-Schiemann reaction.1a,bRadiolabelled 18F compounds
The halex reaction is a great way to introduce a fluorine atom in to an aromatic ring, but the reaction often requires high temperatures and or long reaction times if metal fluorides are used. Tetralkylammonium fluorides are a better option due to their higher solubility in the reaction medium, however these salts are often hydrated