Pd-catalyzed regioselective rollover dual C-H annulation cascade: facile approach to phenanthrene derivatives

Annulations of unsaturated systems through C-H activation represent a powerful tool for producing multicyclic scaffolds. Having coordinating centers in both annulation partners (a dual coordination strategy) would afford remarkable selectivities in the outcomes. Along this concept, we report herein a Pd-catalyzed regioselective rollover cascade dual C-H annulation of o-arylphenols with alkynols for constructing phenanthrene scaffolds. Control, KIE and deuteration studies were conducted to determine the reaction mechanism, and downstream transformations and scaled-up reactions were carried out to assess the robustness of the transformation.

Automated summary

Annulations of unsaturated systems through C-H activation are a powerful tool for producing multicyclic scaffolds. Employing a dual coordination strategy with coordinating centers in both annulation partners can lead to remarkable selectivities. In this study, we report a Pd-catalyzed regioselective rollover cascade dual C-H annulation for constructing phenanthrene scaffolds. Mechanism studies, including control experiments, KIE, and deuteration experiments, were conducted, and downstream transformations and scaled-up reactions were performed to evaluate the robustness of the transformation.