For many years, carbenes were considered to be only unstable intermediates in
organic reactions. However, the synthesis of stable carbenes and their catalytic potential
has attracted many researchers in recent years.
In this work, naturally occurring (1R)-(+)-camphor was used as a chiral backbone for the
synthesis of N-heterocyclic carbenes (NHCs). The camphor framework, which is often
used to prepare bifunctional organocatalysts, serves as an excellent base for the synthesis
of chiral molecules of interest. Starting from the commercially available (1S)-(+)-10-
camphor sulfonic acid, a seven-step synthesis was carried out, yielding two
diastereomeric six-membered NHC precursors, whose catalytic abilities were
investigated. Another nine-step synthesis was carried out, also starting from (1S)-(+)-10-
camphorsulfonic acid, which gave a five-membered NHC precursor in trace amounts.
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