Visible‐Light‐Initiated Dehydrogenative Cyclization of o‐Aminobenzamide and Alcohols for Coproduction of Quinazolinones and Hydrogen over PtS/ZnIn2S4

PtS/ZnIn2S4 nanocomposites are obtained via a microwave-assisted synthesis followed by a photoreduction. The resultant PtS/ZnIn2S4 nanocomposites are used as an effective multifunctional photocatalyst for the reaction between alcohols and o-aminobenzamide to coproduce quinazolinones and hydrogen under visible light, via a cascade alcohols/aldehydes transformation, condensation between aldehydes and o-aminobenzamide, as well as the dehydrogenation/cyclization to produce quinazolinones. PtS acts as an efficient cocatalyst to promote the dehydrogenation of both the alcohols and the condensation intermediates for the production of quinazolinones. An almost complete conversion of o-aminobenzamide was achieved in 24 h, with a yield of 98.8% to 2-phenyl-quinazline-4(3H)-one and quantitative hydrogen produced over PtS/ZnIn2S4 after irradiated for 24 h. The apparent quantum yield at 450 nm is determined to 15.2%. The superior activity observed over PtS/ZnIn2S4 nanocomposite as compared with that over either NiS/ZnIn2S4 or MoS2/ZnIn2S4 can be ascribed to a moderate binding between PtS and the surface adsorbed H*. This study supplies an effective, green, and atom-economic strategy for the synthesis of quinazolinones with coproduction of hydrogen under visible light. This work also demonstrates the high potential of fabrication of metal sulfide-based multifunctional catalysts for light-driven one-pot tandem/cascade reactions.