Asymmetric conjugate addition of cyclic β-keto esters to acetylenicketones has been achieved with high enantioselectivity and moderate E/Z selectivity under the influence of a binaphthyl-modified 3,5-bis[3,5-bis(trifluoromethyl)phenyl]phenyl-substituted phase-transfer catalyst.
Two metal cooperation: A homodinuclear Co2–Schiff basecomplex Co2(OAc)2–1 promoted the asymmetric 1,4‐addition of β‐keto esters to alkynones under solvent‐free conditions in air (see scheme). The reactions proceeded without air or moisture sensitivity in high yields and with high enantioselectivities (99–91 % ee) at room temperature under highly concentrated conditions (neat–20 M) with 0.1–2.5 mol %