The MARDi cascade: A Michael-initiated domino-multicomponent approach for the stereoselective synthesis of seven-membered rings

The MARDi cascade is a recently invented three-component Michael-initiated condensation involving 1,3-dicarbonyl derivatives. It allows regio- and stereocontrolled access to a variety of functionalised and substituted seven-membered rings. The substitution array can be diastereoselectively modulated by appropriate choice of the reaction partners, and the reaction allows the control of up to five newly created stereocentres and a complete chiral induction in the case of an optically active ketone precursor. The high level of diastereoselectivity observed has been attributed to total thermodynamic control of the reaction. The attractiveness of the present domino three-component approach to seven-membered rings resides in the diversity of carbo- and heterocyclic structures that can be accessed with total regio-control and high stereocontrol by starting from simple substrates, under user and environmentally friendly conditions, as now required in modern organic chemistry.