Cyclopropenium ion

The salt was prepared in two steps starting with the reaction of phenyldiazoacetonitrile with diphenylacetylene to yield 1,2,3-triphenyl-2-cyclopropene nitrile.

[13] After using the cyclopropenium ion to form the chloride at the anomeric carbon, the compound is iodinated with tetrabutylammonium iodide.

This iodine can thereafter be substituted by any ROH group to quickly undergo alpha-selective linkage of sugars.

Additionally, some synthetic routes make use of cyclopropenium ring openings yielding an allylcarbene cation.

Such compounds are prepared by reaction of cyclopropenium salts with low valent metal complexes.

[15] Because many substituted derivatives are known, cyclopropenium salts have attracted attention as possible polyelectrolytes, relevant to technologies such as desalination and fuel cells.