In this protocol, we report an allylic defluorinative reductive cross-coupling reaction for C–C bond formation. Under the Ni-catalysis the challenging C­(sp3)–F bond cleavage of trifluoromethyl-substituted alkenes was achieved with easily accessible primary, secondary and tertiary alkyl halides as the coupling partners and Zn-powder as reducing agent. This process provides an efficient and convenient entry to gem-difluoroalkenes bearing various sensitive functional groups under mild reaction conditions. Moreover, this method proves to be suitable for late-stage functionalization of multifunctional complex molecules.

An asymmetric Ni-catalyzed intramolecular reductive Heck reaction of unactivated alkenes tethered to aryl bromides has been accomplished, providing a variety of benzene-fused cyclic compounds bearing a quaternary stereogenic center in good to excellent yields and high enantioselectivities. A mechanism has been proposed, which involves the enantiodetermining migratory insertion and the following protonation with water or alcoholic solvents as the proton source.

Herein, we demonstrate the successful use of robust phenolic esters as an electrophilic acyl source in the reaction with diverse primary and secondary unactivated alkyl bromides. The cleavage of the relatively inert C–O bond is facilitated by the neighboring coordinating hydroxyl or sulfonamide moiety. By circumventing the use of pregenerated organometallics, this method allows efficient preparation of a variety of o-hydroxyl and tosyl-protected o-amino aryl ketones with high compatibility with a wide range of functionalities.

In this context, we report the successful application of a cross-electrophile strategy in the synthesis of multisubstituted allenes. Under the catalysis of nickel, reductive cross-coupling between propargyl carbonates and organoiodides provides an entry to prepare tri- or tetrasubstituted allenes without employing any pregenerated organometallics. Furthermore, propargyl carbonates also prove to be suitable allenylating agents in nickel-catalyzed asymmetric reductive aryl-allenylation of aryl-iodide-tethered unactivated alkenes, furnishing a variety of chiral benzene-fused cyclic compounds bearing a quaternary allenyl-substituted stereogenic center in a highly enantioselective manner.