Catalytic Behavior of Mono-N-Protected Amino-Acid Ligands in Ligand-Accelerated C-H Activation by Palladium(II).
Angew Chem Int Ed Engl
; 59(27): 10873-10877, 2020 06 26.
Article
en En
| MEDLINE
| ID: mdl-32196853
ABSTRACT
Mono-N-protected amino acids (MPAAs) are increasingly common ligands in Pd-catalyzed C-H functionalization reactions. Previous studies have shown how these ligands accelerate catalytic turnover by facilitating the C-H activation step. Here, it is shown that MPAA ligands exhibit a second property commonly associated with ligand-accelerated catalysis the ability to support catalytic turnover at substoichiometric ligand-to-metal ratios. This catalytic role of the MPAA ligand is characterized in stoichiometric C-H activation and catalytic C-H functionalization reactions. Palladacycle formation with substrates bearing carboxylate and pyridine directing groups exhibit a 50-100-fold increase in rate when only 0.05â
equivalents of MPAA are present relative to PdII . These and other mechanistic data indicate that facile exchange between MPAAs and anionic ligands coordinated to PdII enables a single MPAA to support C-H activation at multiple PdII centers.
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Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Paladio
/
Aminoácidos
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Año:
2020
Tipo del documento:
Article
País de afiliación:
Estados Unidos