A Cyclic Diaminocarbene with a Pyramidalized Nitrogen Atom: A Stable N-Heterocyclic Carbene with Enhanced Electrophilicity


  • The authors gratefully acknowledge financial support from the NSF (CHE-1112133), DOE (DE-FG02-09ER16069), and NIH (R01 GM 68825).


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An anti-Bredt NHC! Placing one of the adjacent nitrogen atoms of an NHC in the bridgehead position of a bicyclic scaffold prevents the donation of its lone pair. Thus, the π-electron-accepting properties of the carbene center are enhanced, while the strong σ-electron-donating properties of classical NHCs are retained.