A stable homodinuclear biscobalt(III)-Schiff base complex for catalytic asymmetric 1,4-addition reactions of beta-keto esters to alkynones.
Two metal cooperation: A homodinuclear Co(2)-Schiff base complex Co(2)(OAc)(2)-1 promoted the asymmetric 1,4-addition of beta-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 % catalyst loading.
Chen
Zhihua
Z
Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Furutachi
Makoto
M
Kato
Yuko
Y
Matsunaga
Shigeki
S
Shibasaki
Masakatsu
M
D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D004952:Esters / Q000737:chemistry*; D012545:Schiff Bases / Q000737:chemistry; D013237:Stereoisomerism
D004952:Esters; D012545:Schiff Bases; D003035:Cobalt