Dendritic styryl TADDOLs as novel polymer cross-linkers: First application in an enantioselective Et2Zn addition mediated by a polymer-incorporated titanate

被引：93

作者：

Rheiner, PB ^{[1
]}

Sellner, H ^{[1
]}

Seebach, D ^{[1
]}

机构：

[1] ETH ZENTRUM,ORGAN CHEM LAB,CH-8092 ZURICH,SWITZERLAND

来源：

HELVETICA CHIMICA ACTA | 1997年 / 80卷 / 07期

关键词：

D O I：

10.1002/hlca.19970800702

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

TADDOLs (alpha,alpha,alpha',alpha'-tetraaryl-1,3-dioxolane-4,5-dimethanols) with dendritic branches attached to the aryl groups and with 8 or 16 peripheral styryl double bonds have been synthesized (4 and 5). With these compounds, dendritic molecules were employed for the first time as cross-linkers in a polymerization. The resulting polystyrene was loaded with titanate (Ti(OCHMe2)(4)) to generate polymer beads incorporating Ti-TADDOLate centers (Figs. 1 and 2) for enantioselective catalysis (Et2Zn addition to PhCHO). Compared with conventionally polymer-attached, insoluble Ti-TADDOLates (cf. 3), the new materials have a much higher catalytic activity, rather close to that of soluble analogs (Fig. 3).

引用

页码：2027 / 2032

页数：6

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