Environmentally friendly organic synthesis using bismuth compounds. Bismuth(III) bromide catalyzed synthesis of substituted tetrahydroquinoline derivatives

The bismuth bromide catalyzed synthesis of a range of substituted tetrahydroquinoline derivatives via a three component coupling reaction between substituted anilines and enol ethers is reported. Bismuth compounds are attractive for use as catalysts because of their remarkably low toxicity. Bismuth bromide is relatively inexpensive and easy to handle, and hence preferable to other corrosive catalysts previously used for synthesis of tetrahydroquinoline derivatives.