Bicyclic (Alkyl)(amino)carbenes (BICAACs): Stable Carbenes More Ambiphilic than CAACs

A straightforward strategy allows
for the synthesis of storable
bicyclic (alkyl)­(amino)­carbenes (BICAACs), which feature enhanced
σ-donating and π-accepting properties compared to monocyclic
(alkyl)­(amino)­carbenes (CAACs). Due to the bicyclo[2.2.2]­octane skeleton,
the steric environment around the carbene center is different from
that of CAACs and similar to that observed in classical N-heterocyclic carbenes. The different electronic properties of BICAACs
as compared to CAACs allow for ligand exchange reactions not only
at a metal center, but also at main group elements.