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Updated: May 10, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
Observation of a stable carbene at the active site of a thiamin enzyme
Danilo Meyer1, Piotr Neumann, Ralf Ficner
1Albrecht-von-Haller Institute, Göttingen Center for Molecular Biosciences, Ernst-Caspari-Haus, Georg-August University Göttingen, Göttingen, Germany.
Abstract:
Carbenes are highly reactive chemical compounds that are exploited as ligands in organometallic chemistry and are powerful organic catalysts. They were postulated to occur as transient intermediates in enzymes, yet their existence in a biological system could never be demonstrated directly. We present spectroscopic and structural data of a thiamin enzyme in a noncovalent complex with substrate, which implicate accumulation of a stable carbene as a major resonance contributor to deprotonated thiamin.
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