Figure 8. Asymmetric C_sp³–C_sp³ cross-coupling reactions.

a, The first example of an asymmetric C_sp³–C_sp³ cross-coupling between a racemic α-bromoamide (47) and aliphatic organozinc reagent. b, Proposed mechanism for the coupling reaction. A racemic aliphatic halide adjacent to a directing group (in box) undergoes oxidative addition. Since it is proposed to proceed an unligated aliphatic radical (48) as shown in Figure 7a, the overall oxidative addition is stereoconvergent, and thus the chiral ligand on nickel dictates the stereochemistry of the product. Many classes of directing groups and transmetallating reagents have been successfully reacted, generally relying on one of the three chiral ligand classes shown in the box. Bn, benzyl; DMI, 1,3-dimethyl-2-imidazolidinone.