A tri‐ing reaction: An asymmetricDiels–Alder cycloaddition of δ,δ‐disubstituted 2,4‐dienones is possible through the trienaminecatalysis of cinchona‐based primary amines (see scheme). An array of electron‐deficient dienophiles, such as N‐substituted maleimides and 3‐alkenyl oxindoles, were tolerated, and multifunctional cyclohexene derivatives were obtained in excellent stereoselectivity and with
Carbon–carbon bond formation between α-halogenoketones and aldehydes promoted by cerium(<scp>III</scp>) iodide or cerium(<scp>III</scp>) chloride–sodium iodide
α-Halogenoketones react with aldehydes to form α,β-unsaturated ketones accompanied by dehalogenation in the presence of cerium(III) iodide, but use of cerium(III) chloride–sodiumiodide results in the formation of β-keto alcohols.