Appropriately substituted 2-alkenylphenols undergo a mild formal [3C+2C] cycloaddition with alkynes when treated with a Rh(III) catalyst and an oxidant. The reaction, which involves the cleavage of the terminal C–H bond of the alkenyl moiety and the dearomatization of the phenol ring, provides a versatile and efficient approach to highly appealing spirocyclic skeletons and occurs with high selectivity.

Pd(II)-catalyzed C–H bond functionalizations that proceed under ambient conditions are a pivotal part of the future of chemical synthesis. Herein, an amine directed Pd(II)-catalyzed C–H bond functionalization strategy is described that generates a diversity of molecular frameworks via C–H carbonylation, C–H arylation and C–H amination. The new reactions work for a variety of substrates and are tolerant of delicate stereogenic centres and functionality. Furthermore, the new reactions can be sequenced to generate complex architectures from simple building blocks via iterative Pd(II)-catalyzed C–H bond functionalization.