Unique Molecular Discrimination in Europium Complex-Catalyzed Reactions of Saturated and α,β-Unsaturated Ketones with Ketene Silyl Acetals

Chemoselective Aldol Reaction of Silyl Enolates Catalyzed by MgI2 Etherate

“…The discriminating ability of silyl enolates is inversely dependent on their relative nucleophilicity in the sequence 2 < 3 ∼ 4 . Similar electronic effects of Lewis acidic Eu(dppm) 3 were documented by Mikami and Nakai et al in chemoselective aldol and Michael reactions of aryl aldehydes with silyl enolate of type 2 .…”

“Asymmetric” Catalysis by Lanthanide Complexes

“…(15); fod 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-octanedione]. [31] The competition of the cyclic ketone and enone led to the exclusive formation of the 1,4-addition product. This discriminating ability of the Eu III catalysis is remarkable when compared with the poor ability of stoichiometric TiCl 4 .…”

“…[59] Marks has developed the enantioselective hydrogenation of 2-phenyl-1-butene [Eq. (31)]. [59a, 60] Incorporation of a chiral menthyl group in the 3-position of an ansa-bis(cyclopentadienyl)ligand leads to two diastereomeric complexes of samarium ( Figure 10).…”

Enantioselective Total Synthesis of a trans‐Hydrindane Rings/Side‐Chain Building‐Block of Vitamin D − Asymmetric Induction in an Acid‐Catalyzed Conjugate‐Addition Reaction

“…In order to prepare the subsequent side-chain precursor, the unsaturated ester [40] 22 (Scheme 5) was subjected to the dihydroxylation procedure to give the five-membered lactone [41] Finally, the thioester 27 (Scheme 6), lacking geminal methyl groups at the chain terminus, was obtained from the methyl ester 26, itself synthesized from the -glutamic acid (25), essentially following literature procedures. [42,43] Scheme 6.…”