Atomically precise ultrasmall copper cluster for room-temperature highly regioselective dehydrogenative coupling.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37898608.
- Also identified by DOI 10.1038/s41467-023-42688-3 and PMC identifier 10613312.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Three-component dehydrogenative coupling reactions represent important and practical methodologies for forging new C-N bonds and C-C bonds. Achieving highly all-in-one dehydrogenative coupling functionalization by a single catalytic system remains a great challenge. Herein, we develop a rigid-flexible-coupled copper cluster [Cu<sub>3</sub>(NHC)<sub>3</sub>(PF<sub>6</sub>)<sub>3</sub>] (Cu<sub>3</sub>NC<sup>(NHC)</sup>) using a tridentate N-heterocyclic carbene ligand. The shell ligand endows Cu<sub>3</sub>NC<sup>(NHC)</sup> with dual attributes, including rigidity and flexibility, to improve activity and stability. The Cu<sub>3</sub>NC<sup>(NHC)</sup> is applied to catalyze both highly all-in-one dehydrogenative coupling transformations. Mechanistic studies and density functional theory illustrate that the improved regioselectivity is derived from the low energy of ion pair with copper acetylide and endo-iminium ions and the low transition state, which originates from the unique physicochemical properties of the Cu<sub>3</sub>NC<sup>(NHC)</sup> catalyst. This work highlights the importance of N-heterocyclic carbene in the modification of copper clusters, providing a new design rule to protect cluster catalytic centers and enhance catalysis.