Oxygen-vacancy-rich InBO3 synergizing with K2S2O8 for oxidative trifluoromethylation of styrene under mild condition

Sol-gel-derived oxygen-vacancy InBO 3 activates peroxydisulfate to catalyze styrene oxidative trifluoromethylation into trifluoromethyl phenyl ketone. • Oxygen-deficient InBO 3 -5 achieves an optimal product yield of 41.57%. • Oxygen-vacancy-derived reactive oxygen species cooperate with activated PDS to produce CF 3 radicals. • This system offers a green new route to trifluoromethylated carbonyl compounds. The difunctionalization of alkenes is an efficient strategy for the synthesis of complex molecules, among which oxidative trifluoromethylation represents a direct route to α-trifluoromethylated ketones, an important class of fluorine-containing building blocks. Herein, the combination of an oxygen-vacancy-rich heterogeneous catalyst InBO 3 with K 2 S 2 O 8 was designed to realize the oxidative trifluoromethylation of styrene under mild conditions. In this system, oxygen vacancies mediate the activation of O 2 to generate superoxide anion radical ( O · − 2 ) and singlet oxygen ( 1 O 2 ), which in turn synergize with K 2 S 2 O 8 to activate CF 3 SO 2 Na, producing ∙CF 3 radicals. A radical addition-oxidation pathway then affords the desired product, α-trifluoromethylacetophenone. Using a citric acid modulation strategy, a series of InBO 3 -X catalysts with tunable oxygen vacancy concentrations were successfully prepared. Among them, InBO 3 -5 achieved a product yield of 41.57%. This catalytic system features advantages such as catalyst recyclability, noble-metal-free composition, and mild reaction conditions, providing a new strategy for the green synthesis of trifluoromethylated carbonyl compounds. Oxygen-vacancy InBO 3 -mediated K 2 S 2 O 8 activation toward styrene trifluoromethylation. Download: Download high-res image (127KB) Download: Download full-size image