Resolved, axially chiralbinol scaffolds, which incorporate either methoxy or acetoxy functionalities in the 2,2' positions and carboxylic functionalities in the external 3,3' positions, were used as the source of chirality. Two of these binaphthyls are joined through amidation reactions using rigid diaryl amines of differing shapes, to give homochiral tetraamidic macrocycles. The recognition properties of
Polymer-Supported BINOL Ligand for the Titanium-Catalyzed Diethylzinc Addition to Aldehydes: A Remarkable Positive Influence of the Support on the Enantioselectivity of the Catalyst
作者:Xiao-Wu Yang、Jian-Heng Sheng、Chao-Shan Da、Heng-Shan Wang、Wu Su、Rui Wang、Albert S. C. Chan
DOI:10.1021/jo990771p
日期:2000.1.1
A new polymer-supported BINOL (1,1'-Bi-2-naphthol) :was synthesized by coupling of aminomethyl polystyrene resin and (S)-2,2'-dihydroxy-1,1'-binaphthyl-3,3'-dicarboxylic acid. This new ligand was found to be more enantioselective for the asymmetric addition of diethylzinc to aldehydes than its "free" analog [Ti(BINOL)(PrO2)-Pr-i]. A range of 57-99% ee's as well as 78-97% yields was obtained, and: the electronic properties of the enantioselectivity were also observed.