Wavelength-Selective C–C and C–N Bond Formation via Defect-Engineered ZnIn2S4

Visible light induced oxidative C–C and C–N coupling provides a milder alternative to the current synthetic strategies. However, the photochemical C–C coupling of benzylamine and chromoselective C–C/C–N conversion are not widely reported. Herein, we demonstrate that the introduction of indium vacancies in ZnIn2S4 improves the catalytic activity for C–C coupling of benzylamine and imparts a strong chromoselectivity for C–C or C–N coupled products. A high C–C selectivity of ∼80% is achieved with a benzylamine conversion of ∼80%. Mechanistic studies unveil the switchable reaction routes between kinetically favored C–C coupling and thermodynamically favored C–N coupling under specific illumination conditions.