C1-symmetric aminosulfoximines in copper-catalyzed asymmetric vinylogous Mukaiyama aldol reactions.

Vinylogous Mukaiyama-type aldol reactions have been catalyzed by a combination of Cu(OTf)2 and readily available C1-symmetric aminosulfoximines. After a fine-tuning of the reaction conditions and an optimization of the modularly assembled ligand structure, high stereoselectivities and excellent yields have been achieved in catalyzed reactions involving various electrophile/nucleophile combinations. The relative and absolute configurations of two products were assigned by X-ray single crystal structure analysis and a comparison of calculated and experimental CD spectra.