Asymmetric Ni-Catalyzed Conjugate Allylation of Activated Enones
作者:Joshua D. Sieber、James P. Morken
DOI:10.1021/ja710922h
日期:2008.4.1
The nickel-catalyzedenantioselective addition of allylboronic acid pinacol ester, allylB(pin), is described. This reaction is highly effective with dialkylidene ketones and favors the allylation of the benzylidene site in nonsymmetric substrates. The reaction appears to proceed by conversion of the dialkylidene ketone substrate to an unsaturated pi-allyl complex (I), followed by reductive elimination
Catalytic Conjugate Addition of Allyl Groups to Styryl-Activated Enones
作者:Joshua D. Sieber、Shubin Liu、James P. Morken
DOI:10.1021/ja067878w
日期:2007.2.1
Conjugateaddition of pinacolato(allyl)boron to benzylidenealkylidene ketones is remarkably facile when catalyzed by Ni(0) and Pd(0) complexes. Simpleenones are inert to the reaction conditions, suggesting a significant activating effect by the auxiliary benzylidene unit. A comparison of different catalysts and substrates is provided, as is a mechanistic rationale, and an example of asymmetric catalysis