C-N Coupling of 3-Aminothiophene with Substituted Benzenediazonium Cations: Carbon Nucleophilicity, Hyper-Ortho Effects, and Predictive Modeling of Structural Analogs.

ABSTRACT: This review has kinetically investigated the electrophilic attack of 3-aminothiophene 1 by a series of para-substituted benzenediazonium cations 7a-7h in 50% H₂O-50% Me₂SO at 20 °C using stopped-flow spectrophotometry. No kinetic isotope effect is observed with the 2-deuterio-3-aminothiophene, confirming that the rate-determining step is a carbon-based electrophilic aromatic substitution (S_EAr) at the C-2 position. The Hammett plot with σ_p values shows nonlinearity due to electron-donating substituents. However, a linear relationship is obtained using the Yukawa-Tsuno equation, highlighting the resonance contribution via the r(σ_p ⁺ - σ_p) term. An excellent linear correlation (R² ≈ 0.9968) is observed be

SUBMITTER: El Abed R 

PROVIDER: S-EPMC12710183 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature