Total synthesis of aristolactam alkaloids: Via synergistic C-H bond activation and dehydro-Diels-Alder reactions

A concise total synthesis of aristolactam alkaloids by a synergistic combination of C-H bond activation and dehydro-Diels-Alder reactions is described. To achieve the synthesis two new synthetic methodologies, namely the oxidative cyclization of benzamides with vinyl sulfone leading to 3-methyleneisoindolin-1-ones via a ruthenium-catalyzed C-H bond activation, and a dehydro-Diels-Alder reaction followed by the fluoride ion mediated desulfonylation of 3-methyleneisoindolin-1-ones with benzynes, were developed. The method presented allows the opportunity for the construction of all the rings of aristolactams from easily available starting materials.