Ti-Catalyzed Radical Alkylation of Secondary and Tertiary Alkyl Chlorides Using Michael Acceptors

Alkyl
chlorides are common functional groups in synthetic organic
chemistry. However, the engagement of unactivated alkyl chlorides,
especially tertiary alkyl chlorides, in transition-metal-catalyzed
C–C bond formation remains challenging. Herein, we describe
the development of a TiIII-catalyzed radical addition of
2° and 3° alkyl chlorides to electron-deficient alkenes.
Mechanistic data are consistent with inner-sphere activation of the
C–Cl bond featuring TiIII-mediated Cl atom abstraction.
Evidence suggests that the active TiIII catalyst is generated
from the TiIV precursor in a Lewis-acid-assisted electron
transfer process.