关键词: 1, 1-联萘-2-酚, 非均相催化剂, 不对称加成反应

Abstract: Anew polymer supported BINOLligand(4) was prepared by means of anchoring binaphthyl molecule(3) to aminoethylated polystyrene through a procedure of solid phase peptide synthesis. The key compound (R)-2,2'-dihydroxy 1,1'-binaphthyl-3-carboxylic acid(3) was prepared from R BINOLby protection of hydroxyl groups and then reaction with n-butyllithium followed by carboxylation. By controlling the amount of BuLi, (3) was obtained in 55% overall yield. Ligand (4) was prepared through condensation of (3) with aminoethylated polystyrene in the presence of DCCand HOBt and found to have a loading of 0.40 mmol/g (by mass increase). The linkage between binaphthyl and aminoethylated polystyrene was indicated by a new absorption in IRspectrum of (4) at 1644 cm^-1 in comparing with what of the polystyrene. By mixing (4) with Ti(OiPr)₄ in dry CH₂Cl₂, a complex was easily prepared and this complex was found to be an efficient heterogeneous catalyst in asymmetric addition of diethylzinc to aldehydes. Optical active alcohols with up to 82% ee were obtained from the asymmtric addition with high chemical yields when 20% of (4) was used. And when benzaldehyde was used as substrate, we found that enantioselectivity increased obviously when the amount of (4) used in reaction increased from 5% to 20%;decreased the load of BINOLin ligand (4) reduced the ee of addition product; and Rform of products was resulted.

Key words: 1,1'-Bi-2-naphthol, Heterogeneous catalyst, Enantioselective addition