Carbon nitride as a heterogeneous visible-light photocatalyst for the Minisci reaction and coupling to H2 production

Abstract

Cyanamide functionalised carbon nitride powder is reported as a photocatalyst for direct Minisci-type coupling of heteroarenes with ethers, alcohols, and amides using atmospheric oxygen as the oxidant at room temperature. This mild protocol displays broad substrate scope, good functional group tolerance and the catalyst can be easily isolated and reused for several cycles. It thereby addresses the two major limitations of previously reported photoredox-mediated Minisci reactions: (i) use of expensive and potentially harmful non-recyclable photocatalysts, and (ii) requirement of a stoichiometric amount of strong chemical oxidant. Finally, using platinum as a co-catalyst with the carbon nitride allows this light-mediated reaction to generate two value-added products under an anaerobic atmosphere – functionalised heteroarenes and H₂ fuel.