Reductive C-O, C-N, and C-S Cleavage by a Zirconium Catalyzed Hydrometalation/β-Elimination Approach

A zirconium catalyzed reductive cleavage of C-sp(3) and C-sp(2) carbon-heteroatom bonds is reported that makes use of a tethered alkene functionality as a traceless directing group. The reaction is successfully demonstrated on C-O, C-N, and C-S bonds and proposed to proceed via a hydrozirconation/beta-heteroatom elimination sequence of an in situ formed zirconium hydride catalyst. The positional isomerization of the catalyst further enables the cleavage of homoallylic ethers and the removal of terminal allyl and propargyl groups.