One-pot synthesis of quaternary carbon centered cyclobutanes via Pd(ii)-catalyzed cascade C(sp3)-H activations.

A novel approach toward quaternary carbon centered cyclobutanes through Pd(ii)-catalyzed sequential intramolecular methylene C-H alkylation and intermolecular methine C-H bond arylation, alkenylation, alkylation, alkynylation, allylation, benzylation or alkoxylation is described. These quaternary carbon centered cyclobutanes could be further diversified through Pd(ii)-catalyzed γ-C(sp3)-H bond activations. The synthetic utility of this novel approach was exemplified by its application to the synthesis of a bioactive small molecule.