Radiolabeling with [¹¹C]HCN for Positron emission tomography

Area of Science:

• Organic Chemistry
• Radiochemistry
• Medicinal Chemistry

Background:

• Hydrogen cyanide (HCN) is a key one-carbon synthon used for C-C and C-heteroatom bond formation.
• Its ability to act as both a nucleophile and electrophile makes it valuable for synthesizing diverse organic molecules.
• The CN group is a precursor to nitriles, hydantoins, and (thio)cyanates, which can be transformed into various functional groups.

Purpose of the Study:

• To review the synthesis and applications of carbon-11 labeled hydrogen cyanide ([11C]HCN) in positron emission tomography (PET) radiochemistry.
• To summarize historical and current methods for [11C]HCN production and its use in radiolabeling.
• To discuss the chemical transformations of nitriles derived from [11C]HCN for creating novel PET tracers.

Main Methods:

• Review of literature on [11C]HCN synthesis and radiolabeling techniques.
• Analysis of chemical reactions for incorporating the [11C]CN motif into organic molecules.
• Overview of methods for converting [11C]nitrile products into other functional groups.

Main Results:

• [11C]HCN has been utilized for radiolabeling since the 1960s, enabling the synthesis of various biologically important molecules.
• The versatility of [11C]cyanation is driving its resurgence in PET centers for developing new tracers.
• Established methods exist for synthesizing [11C]HCN and labeling diverse molecules, with ongoing research into nitrile functional group transformations.

Conclusions:

• [11C]HCN remains a valuable tool in PET radiochemistry due to its synthetic versatility.
• Further development is needed for more robust [11C]HCN production methods and efficient nitrile conversions in complex molecules.
• The reemergence of [11C]cyanation offers significant opportunities for creating novel PET imaging agents.