Reductive Generation of Enolates from Enones Using Elemental Hydrogen: Catalytic C−C Bond Formation under Hydrogenative Conditions
作者:Hye-Young Jang、Ryan R. Huddleston、Michael J. Krische
DOI:10.1021/ja021163l
日期:2002.12.1
the presence of a Rh(I) catalyst enables reductive enolate generation, as evidenced by electrophilic trapping of the enolate by appendant and exogenous aldehyde partners. The significance of these findings resides in the ability to regioselectivity generate and transform transition metal enolatesunder catalytic conditions that circumvent formation of stoichiometric byproducts.
Dual Catalyst Control in the Enantioselective Intramolecular Morita−Baylis−Hillman Reaction
作者:Carrie E. Aroyan、Melissa M. Vasbinder、Scott J. Miller
DOI:10.1021/ol0513544
日期:2005.9.1
The intramolecularMorita-Baylis-Hillman (MBH) reaction has been achieved with unprecedented levels of enantioselectivity. Using a co-catalyst system involving pipecolinic acid and N-methylimidazole, cyclic MBH products have been obtained with enantiomer ratios of 92:8 (84% ee). In addition, reactions may be carried out with a "kinetic resolution quench" involving acetic anhydride and an asymmetric