55830-03-0Relevant articles and documents
Nickel-catalyzed conjugate addition of arylboron reagents to α,β-unsaturated carbonyl compounds with the aid of a catalytic amount of an alkyne
Shirakawa, Eiji,Yasuhara, Yuichi,Hayashi, Tamio
, p. 768 - 769 (2006)
Alkynes in combination with a catalytic amount of a nickel complex were found to catalyze the conjugate addition of arylboron reagents to α,β-unsaturated carbonyl compounds, where use of an optically active alkyne induces the asymmetric addition. Copyright
Mechanism of the Grignard Adddition Reaction. XVI. Homolytic and Concerted Mechanisms in the Reaction of α,β-Unsatureted Carbonyl Compounds with Grignard Reagents
Holm, Torkil
, p. 925 - 929 (2007/10/02)
Kinetic measurements have shown that the addition of Grignard reagents to α,β-unsaturated carbonyl compounds takes place either by a concerted mechanism or by a homolytic mechanism.Phenylmagnesium bromide, which is incapable of homolysis, reacts rapidly in a 1,4-fashion if an s-cis conformation exists between the C=C and the C=O bonds, but only 1,2-addition takes place if the conformation is s-trans.tert-Butylmagnesium bromide is unsuited to the concerted reaction, but 1,4-addition takes place via homolysis.Primary and secondary Grignard reagents, like phenyl, react rapidly in a concerted manner with s-cis substrates, but unlike phenyl, these Grignard reagents may, with s-trans substrates, produce some 1,4-adduct via the homolytic mechanism.
