Nickel-catalyzed conjugate addition of alkynyl groups to. alpha.,. beta.-unsaturated ketones
The complex formed by reaction of Ni (acac) 2 and DiBAH (1: 1) catalyzesconjugate addition of dialkylaluminum acetylides to, ß enones;; on hydrolysis, 3-alkynyl ketones are produced in high yield. Through this procedureconjugate addition of alkynyl groups to either S-cis or S-trans enones can be effected. This procedure is thefirst one which permits conjugate addition of terminal alkynyl units to ordinary S-trans enones. In cases wheremore than one stereochemical outcome is possible, conjugate addition of alkynyl units gives only one of these.Only 1,4-addition is observed and this only of the alkynyl unit. Complications arising from oxygen substitutionin the alkynyl side chain are described.
Schwartz, J., Carr, D. B., Hansen, R. T., & Dayrit, F. M. (1980). Nickel-catalyzed conjugate addition of alkynyl groups to. alpha.,. beta.-unsaturated ketones. The Journal of Organic Chemistry, 45(15), 3053-3061.