The addition of organometallic reagents to imines is a fundamental method for the synthesis of amines in the pharmaceutical, agrochemical, and fine chemical industries.  However, this traditional method suffers from several limitations, including the need for stoichiometric organometallic reagents, laborious manipulations, and the generation of unwanted stoichiometric salt wastes, particularly for large-scale preparations. As an alternative to the traditional approach, catalytic reductive coupling between alkenes and imines has emerged as a promising method. The use of easily accessible olefins as carbanion equivalents for nucleophilic addition to imines can obviate the problems associated with the use of organometallic reagents. Extensive studies have been devoted to this field and significant progress has been made in the past two decades. However, the intermolecular, reductive coupling of less active alkenes such as styrenes to common imines is rare.