A simple, solvent-free, one-pot autoxidative coupling reaction between quinoline and indoles or pyrroles is reported. This atom economic method requires only a stoichiometric amount of inexpensive hydrochloric acid and does not require a catalyst.

In this study, a hydrochloric acid-stable 2D covalent organic framework (TpPa-1) was prepared. And its adsorption behaviors in the recovery of palladium (Pd(II)) from acid solution systematically investigated under effect contact time, concentration, chloride ions and capacity. The adsorbed species on TpPa-1 clarified as chloridated Pd(II) by X-ray photoelectron spectroscopy.