RT info:eu-repo/semantics/article
T1 Non‐chelate‐assisted palladium‐catalyzed aerobic oxidative heck reaction of fluorobenzenes and other arenes: When does the C−H activation need help?
A1 Villalba de Pando, Francisco
A1 Albéniz Jiménez, Ana Carmen
K1 Activación C-H
K1 Olefination
K1 Palladium
K1 Ligand cooperation
K1 Oxygen
K1 23 Química
K1 22 Física
AB The pyridone fragment in the ligand [2, 2’-bipyridin]-6(1H)-one (bipy-6-OH) enables the oxidative Heck reaction of simple arenes with oxygen as the sole oxidant and no redox mediator. Arenes with either electron-donating or electron-withdrawing groups can be functionalized in this way. Experimental data on the reaction with toluene as the model arene shows that the C−H activation step is turnover limiting and that the ligand structure is crucial to facilitate the reaction, which supports the involvement of the pyridone fragment in the C−H activation step. In the case of fluoroarenes, the alkenylation of mono and 1,2-difluoro benzenes requires the presence of bipy-6-OH. In contrast, this ligand is detrimental for the alkenylation of 1,3-difluoro, tri, tetra and pentafluoro benzenes which can be carried out using just [Pd(OAc)2]. This correlates with the acidity of the fluoroarenes, the most acidic undergoing easier C−H activation so other steps of the reaction such as the coordination-insertion of the olefin become kinetically important for polyfluorinated arenes. The use of just a catalytic amount of sodium molybdate as a base proved to be optimal in all these reactions.
PB Wiley
SN 1615-4150
YR 2021
FD 2021
LK https://uvadoc.uva.es/handle/10324/49029
UL https://uvadoc.uva.es/handle/10324/49029
LA eng
NO Advanced Synthesis & Catalysis, 2021, vol. 363, p. 1-11
NO Producción Científica
DS UVaDOC
RD 24-nov-2024