title: Silicon-Carbon Bond Formation via Nickel-Catalyzed Cross-Coupling of Silicon Nucleophiles with Unactivated Secondary and Tertiary Alkyl Electrophiles.
abstract: A wide array of cross-coupling methods for the formation of C-C bonds from unactivated alkyl electrophiles have been described in recent years. In contrast, progress in the development of methods for the construction of C-heteroatom bonds has lagged; for example, there have been no reports of metal-catalyzed cross-couplings of unactivated secondary or tertiary alkyl halides with silicon nucleophiles to form C-Si bonds. In this study, we address this challenge, establishing that a simple, commercially available nickel catalyst (NiBr2·diglyme) can achieve couplings of alkyl bromides with nucleophilic silicon reagents under unusually mild conditions (e.g., -20 °C); especially noteworthy is our ability to employ unactivated tertiary alkyl halides as electrophilic coupling partners, which is still relatively uncommon in the field of cross-coupling chemistry. Stereochemical, relative reactivity, and radical-trap studies are consistent with a homolytic pathway for C-X bond cleavage.
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Crystal K
authors.initials: CK
authors.lastname: Chu
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Yufan
authors.initials: Y
authors.lastname: Liang
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Gregory C
authors.initials: GC
authors.lastname: Fu
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D009532:Nickel / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*
chemical_list: D002244:Carbon; D009532:Nickel; D012825:Silicon