Reductive Dicarbofunctionalization of C–C π-Bonds

Transition metal-catalyzed difunctionalization of C–C π-bonds (alkenes, alkynes, 1,3-dienes, and allenes), namely the addition of two functional groups across an unsaturated system, has emerged as a powerful synthetic tool for the rapid construction of complex molecules and has broad applications in organic synthesis. Compared with the traditional redox-neutral and oxidative dicarbofunctionalization of C–C π-bonds, transition-metal catalyzed reductive dicarbofunctionalization can introduce two different carbon electrophiles to both sides of the C–C π-bonds, allowing the reaction to proceed under milder conditions, with superior functional group tolerance, and without the need for pre-formed organometallic reagents. However, dicarbofunctionalization of different types of C–C π-bonds faces great challenges in terms of reactivity, chemo-, regio- and stereoselectivity. In this chapter, we aim to provide a detailed and informative journey toward the reductive dicarbofunctionalization of C–C π-bonds, including alkenes, alkynes, 1,3-dienes and allenes. Importantly, we discuss the reaction mechanisms of these approaches, emphasizing the important role of ligands in modulating reaction selectivity, and highlighting current opportunities.