A simple primary-secondary diamine organocatalyst catalyzes the cascade Michael–aldol–dehydration of chalcones and unmodified ketones to produce substituted cyclohex-2-enones under mild conditions with good yields and high enantio- and/or diastereoselectivities. The success of the catalyst system is possibly due to simultaneous activation of the electrophilic chalcone by iminium formation and the nucleophilic ketone by enamine formation with an overall intramolecular iminium–di-enamine mechanism.