Periphery-Arranged Bulky Phosphite Ligands: Synthesis and Steric Effect in Cu-Catalyzed Hydrosilylation of Ketones

A series of periphery-arranged bulky phosphites were
synthesized,
characterized, and applied as a ligand for the Cu-catalyzed hydrosilylation
of ketones. These bulky phosphite ligands are highly efficient compared
with conventional phosphite ligands. The bulkiness of the phosphite
at the periphery works effectively by suppressing aggregation of the
active copper species. The origin of the steric effect and reaction
mechanism is discussed based on kinetic studies and density functional
theory (DFT) calculations.