Four hydroxyls are better than two. The use of a chiral lithium salt of 3,3′-bis-methanol-2,2′-binaphthol as a multifunctional catalyst of enantioselective Michael addition reactions

The catalytic performance of the Li salt of (S)- or (R)-3,3′-bis[bis-(phenyl)hydroxymethyl]-2,2′-dihydroxy-dinaphthalene-1,1′ (BIMBOL) in asymmetric Michael additions of malonic acid derivatives and toluedine has been studied. Nitrostyrene and cyclohex-2-enone were chosen as Michael acceptors. Efficient asymmetric C–C and C–N bond formations with ee’s of up to 95% at room temperature were observed. A transition state model of the malonic ester addition to cyclohex-2-enone has been proposed based on the molecular structure of the acetone solvate of BIMBOL. The impact of the catalyst self-association on its performance is also discussed.

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(R)-3,3′-Bis(hydroxydiphenylmethyl)-1,1′-binaphthyl-2,2′-diolC46H34O4[α]D25=+112 (c 1, CHCl3)Source of chirality: resolutionAbsolute configuration: (R)

(3S)-Ethyl-2-acetyl-4-nitro-3-phenylbutyrateC14H17NO5[α]D25=-28.1 (c 0.57, CHCl3)Source of chirality: asymmetric catalysisAbsolute configuration: (2R,3R)

Diethyl 2-(3-oxocyclohexyl)malonateC13H19O5[α]D25=+2.7 (c 0.73, CHCl3)Source of chirality: asymmetric catalysisAbsolute configuration: (R)