Ag(I)-C-H Activation Enables Near-Room-Temperature Direct α-Arylation of Benzo[ b]thiophenes
Related Experiment Video
Updated: Feb 8, 2026

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines
Published on: June 23, 2019
Chiara Colletto1, Adyasha Panigrahi1, Jaime Fernández-Casado1
1School of Chemistry , University of Manchester , Oxford Road , Manchester M13 9PL , U.K.
Abstract:
The first example of near-room-temperature α-arylation of benzo[ b]thiophenes is reported. The discovery rests on the observation of a switch in α-/β-regioselectivity at different loadings of Pd2(dba)3·CHCl3 in the coupling between benzo[ b]thiophene and 4-iodotoluene. We show that this unprecedented regioselectivity switch is driven by a Ag(I)-mediated C-H activation at the α-C-H position, which becomes the dominant mode of reactivity at low concentrations of Pd. Competition experiments, kinetic studies, KIE, and D/H scrambling experiments have been carried out supporting this mechanism.
Related Concept Videos
Nomenclature of Aryl and Heterocyclic Amines
Direct-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
The direct-acting...
Temperature Dependence on Reaction Rate
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
Body Temperature
Body Temperature
The average body temperature is approximately 37°C (98.6°F) and typically ranges from 36.1–37.2°C...
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3

