Chiral β-allyl carbonyl compounds are important chiral building blocks, which are ubiquitously found in biologically active natural products. Therefore, the development of efficient strategies for the synthesis of chiral β-allyl carbonyls has attracted extensive attention from synthetic chemists and has emerged as a prominent research focus in recent years. Transition-metal-catalyzed asymmetric conjugate allylation of α,β-unsaturated carbonyl compounds represents one of the most straightforward and efficient methodologies for the synthesis of enantiomerically enriched β-allyl carbonyl compounds. The in situ generated allyl metal species serve as active nucleophiles in this reaction. According to the types of electrophilic substrates, recent advances in this field are classified into three categories: asymmetric conjugate allylation of α,β-α’,β’-diunsaturated ketones, 2-arylidene(alkylidene)-1,3-dicarbonyl compounds, and simple α,β-unsaturated carbonyl compounds. The mechanisms and potential applications of some representative methodologies are briefly discussed. Finally, the future perspectives of this field are presented.

Key words: transition metal catalysis, asymmetric catalysis, α,β-unsaturated carbonyl compounds, asymmetric conjugate allylation, allyl metal species