Ligand- and Base-Free Pd(II)-Catalyzed Controlled Switching between Oxidative Heck and Conjugate Addition Reactions
作者:Sarah E. Walker、Julian Boehnke、Pauline E. Glen、Steven Levey、Lisa Patrick、James A. Jordan-Hore、Ai-Lan Lee
DOI:10.1021/ol400539h
日期:2013.4.19
solvent allows controlled and efficient switching between oxidative Heck and conjugateadditionreactions on cyclic Michael acceptor substrates, catalyzed by a cationic Pd(II) catalyst system. Both reactions are ligand- and base-free and tolerant of air and moisture, and the controlled switching sheds light on some of the factors which favor one reaction over the other.
Mild and Ligand-Free Pd(II)-Catalyzed Conjugate Additions to Hindered γ-Substituted Cyclohexenones
作者:James A. Jordan-Hore、James N. Sanderson、Ai-Lan Lee
DOI:10.1021/ol300794a
日期:2012.5.18
Ligand-free cationic Pd(II) catalyst with NaNO3 as an additive is a highly active catalytic system for conjugate additions to sterically hindered gamma-substituted cyclohexenones. More challenging gamma gamma- and beta gamma-substrates also react well to produce products with quaternary centers in good dr. The conjugate additions occur in a diastereoselective fashion under mild, practical and air-stable conditions, using readily available commercial reagents.