Palladium-catalyzed aryl-aryl cross-coupling reaction using ortho-substituted arylindium reagents.

A range of biaryl compounds (aryl- aryl, aryl- heteroaryl, and heteroaryl- heteroaryl) can be efficiently prepared by a palladium-catalyzed cross-coupling reaction between ortho-substituted triarylindium reagents and aryl halides. The triarylindium reagents are prepared by directed ortho-lithiation and transmetallation to indium from the corresponding benzene derivatives using various directed metallation groups (DMGs). The reaction proceeds smoothly in high yields and short reaction times with high atom economy (the three aryl groups attached to indium are efficiently transferred).