Cobaltcomplex/Zn systems effectively catalyze the reductive coupling of activated alkenes with alkynes in the presence of water to give substituted alkenes with very high regio- and stereoselectivity in excellent yields. While the intermolecular reaction of acrylates, acrylonitriles, and vinyl sulfones with alkynes takes place in the presence of CoI2(PPh3)2/Zn, the reaction of enones and enals with
In the zone: Pd‐catalyzedoxidativecross‐coupling of N‐tosylhydrazones with allylic alcohols leads to CC bond formation. A palladium–carbene migratory insertion is proposed to play the key role in this transformation. The reaction proceeds with readily available starting materials to afford substituted alkenes in a highly stereoselective manner (see scheme).
Catalytic Intermolecular Reductive Coupling of Enones and Alkynes
作者:Ananda Herath、Benjamin B. Thompson、John Montgomery
DOI:10.1021/ja073300q
日期:2007.7.1
A nickel-catalyzed intermolecular reductive coupling of enones and alkynes has been developed as a novel entry to gamma,delta-unsaturated ketones. The process does not require formation of a vinyl organometallic, and a variety of functional groups including free hydroxyls and esters are tolerated. A number of features that complement existing copper-mediated processes are highlighted.
Trost, Barry M.; Martinez, Jose A.; Kulawiec, Robert J., Journal of the American Chemical Society, 1993, vol. 115, # 22, p. 10402 - 10403
作者:Trost, Barry M.、Martinez, Jose A.、Kulawiec, Robert J.、Indolese, Adriano F.