Formation of Allylated Quaternary Carbon Centers via C–O/C–O Bond Fragmentation of Oxalates and Allyl Carbonates
Disclosed herein emphasizes Fe-promoted cross-electrophile allylation of tertiary alkyl oxalates with allyl carbonates that generates all C(sp3)-quaternary centers. The reaction involves fragmentation of tertiary alkyl oxalate C-O bonds to give tertiary alkyl radical intermediates, addition of the radicals to less hindered alkene terminals, and subsequent cleavage of the allyl C–O bonds. Allylation with 2-aryl substituted allyl carbonates was mediated by Zn/MgCl2, and Fe is used to promote the radical addition efficiency. By introduction of activated akenes, a three-component radical cascade reaction took place.