2025-08-19 パシフィック・ノースウェスト国立研究所(PNNL)
＜関連情報＞
- https://www.pnnl.gov/publications/promoting-dihydrogen-activation-copper-catalytic-hydrogenation
- https://onlinelibrary.wiley.com/doi/full/10.1002/anie.202510627
三角平面型ビス(カルベン)Cu(I)錯体は、H2Oを用いたH2の分岐活性化を可能にし、オレフィン水素化を加速する Trigonal Planar Bis(carbene)Cu(I) Complexes Enable Divergent H2 Activation with H2O for Accelerated Olefin Hydrogenation
Dr. Evan A. Patrick, Prof. Dr. Shaama Mallikarjun Sharada, Anya Zoraster, Dr. Jeremy D. Erickson, Dr. David E. Ryan, Dr. R. Morris Bullock, Dr. Ba L. Tran
Angewandte Chemie International Edition Published: 11 June 2025
DOI:https://doi.org/10.1002/anie.202510627
Graphical Abstract
Trigonal planar naphthyridine-bis(carbene)Cu(I) alkyl, hydroxide, and ethoxide complexes promote a divergent mechanism of H2 activation for the rare catalytic hydrogenation of unactivated alkenes at mild conditions at copper.
Abstract
CuH-catalyzed olefin hydrogenation is rare compared to those of carbonyl-derived substrates. Olefin insertion into Cu–H to form Cu-alkyl is ubiquitous; however, subsequent H2 activation remains unknown to our knowledge. Herein, we investigated the transformations of β-H elimination, H2 cleavage, and catalytic olefin hydrogenation in a series of linear and trigonal planar Cu(I)-alkyl complexes supported by monodentate N-heterocyclic carbene and bidentate naphthyridine-bis(carbene) ligands, respectively. Contrary to unreactive linear species, trigonal planar variants promote β-H elimination, hydrogenolysis, and catalytic hydrogenation of unactivated alkenes at mild temperatures and H2 pressure. The rare isolation of a naphthyridine-bis(carbene)CuH monomer further affirms two predominant competing pathways for H2 cleavage of metal–ligand cooperativity at Cu(I)-alkyl or internal electrophilic substitution at Cu(I)-OH. Employing either isolated or in situ generated Cu(I)-OH complex, via protonolysis of alkyl precatalyst by adventitious water, significantly accelerated catalysis compared to that operating primarily by the metal–ligand cooperativity pathway. DFT calculations and energy decomposition analysis on the disparate β-H elimination reactivity between linear and trigonal planar tert-butyl complexes and the mechanism of H2 activation at a hydroxide complex, indicate that coordination geometry at Cu(I) and properties of the naphthyridine-bis(carbene) ligand are integral to the transformations reported here.
