Enantioselective C(sp3)–C(sp3) Cross-Coupling of Non-activated Alkyl Electrophiles via Nickel Hydride Catalysis

2020-03-27T18:00:42Z (GMT) by Srikrishna Bera Runze Mao Xile Hu
Cross-coupling of two alkyl fragments is an efficient method to produce organic molecules rich in sp3-hydridized carbon centers, which are attractive candidate compounds in drug discovery. Enantioselective C(sp3)-C(sp3) coupling, especially of alkyl electrophiles without an activating group (aryl, vinyl, carbonyl) is challenging. Here we report a strategy based on nickel hydride addition to internal olefins followed by nickel-catalyzed alkyl-alkyl coupling. This strategy enables enantioselective cross-coupling of non-activated alkyl iodides with alkenyl boronates to produce chiral alkyl boronates. Employing readily available and stable olefins as pro-chiral nucleophiles, the coupling proceeds under mild conditions and exhibits broad scope and high functional group tolerance. Applications in late-stage functionalization of natural products and drug molecules, synthesis of chiral building blocks, and enantioselective formal synthesis of (S)-(+)-Pregabalin are demonstrated.