2026-08-18 パシフィック・ノースウェスト国立研究所（PNNL）
Spectroscopic characterization of a (DTBM-SEGPHOS)CuH monomer and the dimerization kinetics that lead to deactivation by aggregation.(Image by David E. Ryan | Pacific Northwest National Laboratory)
＜関連情報＞
- https://www.pnnl.gov/publications/characterizing-key-elusive-copper-hydride-intermediate
- https://onlinelibrary.wiley.com/doi/10.1002/anov.70025
捉えどころのない(DTBM-SEGPHOS)CuHモノマーの直接観察により、アルケン官能基化触媒のヒドロクプラ化、凝集、およびダイナミクスに関する機構的洞察が可能になる Direct Observation of Elusive (DTBM-SEGPHOS)CuH Monomer Enables Mechanistic Insights Into Hydrocupration, Aggregation, and Dynamics of Alkene Functionalization Catalysis
David E. Ryan, Jack T. Fuller III, Evan A. Patrick, Jeremy D. Erickson, Greg K. Schenter, Bojana Ginovska, Simone Raugei, R. Morris Bullock, Ba L. Tran
Angewandte Chemie Novit Published: 10 July 2026
DOI:https://doi.org/10.1002/anov.70025
ABSTRACT
The bulky diphosphine DTBM-SEGPHOS is widely employed in CuH-catalyzed transformations as it provides remarkably active catalyst systems. The transient (DTBM-SEGPHOS)CuH monomer (LCuH) is the often-invoked active species. However, its instability has prevented spectroscopic characterization and mechanistic elucidation, hindering mechanistic understanding. We report low-temperature NMR spectroscopic characterization of LCuH, enabling quantitative kinetic analysis of the stoichiometric hydrocupration and catalytic hydroboration of cyclopentene, as well as the structural identification of two CuH clusters. LCuH inserts cyclopentene at −43°C, reaffirming its high reactivity toward olefins. LCuH deactivates to form L2Cu3H3 and L2Cu4H4 clusters, in which LCuH dimerization initiates aggregation. Kinetic analysis of reactions of unactivated alkenes indicates that competing on-cycle alkene hydrocupration and LCuH dimerization impact performance, as catalyst deactivation and turnover occur on comparable timescales. Structure–activity analysis using atomistic simulations shows that the steric profile of DTBM-SEGPHOS increases the CuH dimerization barrier by ∼7.7 kcal mol−1 compared to that of SEGPHOS, rationalizing the unique ability of DTBM-SEGPHOS to stabilize a reactive monomer for hydrocupration of broader alkene substrates. These findings illustrate the fundamental design principle that steric control of aggregation governs CuH catalyst performance, explaining both the exceptional activity of (DTBM-SEGPHOS)CuH and the limitations imposed by competing deactivation.
