Bulky <i>N</i>‐Heterocyclic‐Carbene‐Coordinated Palladium Catalysts for 1,2‐Addition of Arylboron Compounds to Carbonyl Compounds
Yuta Okuda, Masahiro Nagaoka, Tetsuya Yamamoto
Abstract
Abstract The synthesis of primary, secondary, and tertiary alcohols by the 1,2‐addition of arylboronic acids or boronates to carbonyl compounds, including unactivated ketones, using novel bulky yet flexible N ‐heterocyclic carbene (NHC)‐coordinated 2,6‐di(pentan‐3‐yl)aniline (IPent)‐based cyclometallated palladium complexes (CYPs) as catalysts is reported. The PhS‐IPent‐CYP‐catalyzed reactions are efficient at low catalyst loadings (0.02–0.3 mol% Pd), and the exceptional catalytic activity for 1,2‐addition is attributed to the steric bulk of the NHC ligand. These reactions can yield a wide range of functionalized benzylic alcohols that are difficult to synthesize by classical protocols using highly active organomagnesium or lithium reagents.