CdS/Mg–Fe layered double hydroxide: a versatile heterogeneous photocatalyst for the acylation of indoles with α-keto acids

Abstract

The CdS/Mg–Fe layered double hydroxide (LDH) was successfully constructed by coupling CdS and Mg–Fe LDH based on the mutually complementary properties of the two materials. This stable and recyclable heterogeneous photocatalyst was found to realize the C3-acylation of indoles with α-keto acids. The reactions were carried out under irradiation with blue light at room temperature using abundant and inexpensive air as the oxidant. This methodology gives easy access to 3-acyl indoles with high yields. CdS/Mg–Fe LDH can be recovered and reused for multiple runs without obviously losing its photocatalytic activity.