Impact of the Methylene Bridge Substitution in Chelating NHC-Phosphine Mn(I) Catalyst for Ketone Hydrogenation.
- Resource Type
- Article
- Authors
- Gulyaeva, Ekaterina S.; Buhaibeh, Ruqaya; Boundor, Mohamed; Azouzi, Karim; Willot, Jérémy; Bastin, Stéphanie; Duhayon, Carine; Lugan, Noël; Filippov, Oleg A.; Sortais, Jean-Baptiste; Valyaev, Dmitry A.; Canac, Yves
- Source
- Chemistry - A European Journal. 4/16/2024, Vol. 30 Issue 22, p1-11. 11p.
- Subject
- *KETONES
*HYDROGENATION
*CHELATES
*CATALYSTS
*CATALYTIC activity
*CARBENES
- Language
- ISSN
- 0947-6539
Systematic modification of the chelating NHC-phosphine ligand (NHC = N-heterocyclic carbene) in highly efficient ketone hydrogenation Mn(I) catalyst fac-[(Ph2PCH2NHC)Mn(CO)3Br] has been performed and the catalytic activity of the resulting complexes was evaluated using acetophenone as a benchmark substrate. While the variation of phosphine and NHC moieties led to inferior results than for a parent system, the incorporation of a phenyl substituent into the ligand methylene bridge improved catalytic performance by ca. 3 times providing maximal TON values in the range of 15000-20000. Mechanistic investigation combining experimental and computational studies allowed to rationalize this beneficial effect as an enhanced stabilization of reaction intermediates including anionic hydride species fac-[(Ph2PC(Ph)NHC)Mn(CO)3H]-playing a crucial role in the hydrogenation process. These results highlight the interest of such carbon bridge substitution strategy being rarely employed in the design of chemically non-innocent ligands. [ABSTRACT FROM AUTHOR]