Practical and highly enantioselective alkylation of aldehydes catalyzed by a titanium complex of 3-aryl H8-BINOL

A titanium complex derived from 3-(3,5-diphenylphenyl)-H8-BINOL exhibits high catalytic activity and enantioselectivity in the alkylation of aldehydes. Enantioselectivities comparable to or higher than 20 mol % of the parent H8-BINOL are obtained with 2 mol %-catalyst loadings. The reaction can be carried out without rigorous exclusion of water.

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(R)-3-(3,5-Diphenylphenyl)-2,2′-dihydroxy-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthylC38H34O2[α]D25=+69.7 (c 1.00, CHCl3)Source of chirality: (R)-2,2′-dihydroxy-5,5′,6,6′,7,7′,8, 8′-octahydro-1,1′-binaphthylAbsolute configuration: (R)