The Outstanding Ambiphilicity of Trialkylstibines among Trialkylpnictines: Power for Stepwise Deoxygenation and N–N Coupling of Nitroarenes

Abstract

The ongoing discovery of highly reactive ambiphilic main-group species has significantly advanced the development of main-group chemistry, particularly in the realms of small molecule activation and catalysis. Theoretically, compounds featuring smaller HOMO–LUMO gaps gain stronger ambiphilicity and higher reactivity. In this work, we fundamentally demonstrate that Me₃Sb holds the smallest HOMO–LUMO gap among trimethylpnictines, indicating its outstanding ambiphilicity. Correspondingly, the superior reactivity of Me₃Sb toward deoxygenation of electron-deficient nitroarenes has been unambiguously revealed through control experiments. Furthermore, unprecedented Sb^III/Sb^VO cycling between trialkylstibines and their oxides has been established for the catalytic transformation of nitroarenes into azoxyarenes/azoarenes. This study opens a new chapter for organoantimony derivatives in the fields of ambiphilic reactivity and redox catalysis.