不对称催化反应中新型手性膦配体的设计与合成

The high enantiomeric pure phenylglycol was synthesized from styrene by Sharpless asymmetric dihydroxylation.The diol was converted to chiral diphosphine-borane complex by esterification and nucle-ophilic substitution respectively. The complex was superior to free phosphine ligands which are sensitive to atmosphere. It's easy to prepare, purify and reserve. The complex was decomplexated in the presence of HBF4·OMe2 to yield quantitatively the free diphosphine which reacted directly with [Rh(COD)Cl]2 forming in situ catalyst. The asymmetric hydrogenation of methyl z-α-acetamidocinnamate has been accom-plished in the presence of catalyst in 100% chemical conversion and 88%e.e. .. The synthesis of a novel soluble polymer-bound ligand DHQD-PHAL-OPEG-OMe and (DHQD)2PHAL-OPEG copolymer and their application in the catalytic asymmetric dihydroxylation (AD) reaction are described. 1,4-Dichlorophthalazine was used as the coupling reagent to connect dihydroquinidine and polyethylene glycol monomethyl ether (MW = 5000, Fluka) while providing an aromatic group at the 9-O-position of dihydroquinidine. Enantiomeric excesses for trans-disubstituted olefins in the AD reaction, with K3Fe(CN)6 as secondary oxidant, are up to 98%.

用‘一锅煮’一步操作合成两个具有C2-对称轴的新型大环手性双膦配体和两个P-N类型的手性配体。观察它们的铑或钯络合物催化剂对碳碳、碳氧和碳氮双键的催化氢化反应及烯丙位取代反应的催化活性和立体选择性。获得手性化合物是化学家梦寐以求的目标，而不对称催化反应获得这类物质最科学的方法。本课题为制备手性膦配体提供了一条崭新的简便途径。