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

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.