DEVELOPMENT OF MODIFIED CYCLODEXTRINS FOR SELECTIVE ORGANIC SYNTHESIS

用于选择性有机合成的改性环糊精的开发

基本信息

批准号：
04453085
负责人：
KOMIYAMA Makoto
金额：
$ 3.9万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04453085/
关键词：
Cyclodextrin Phenol Formaldehyde Modified cyclodextrin Selective synthesis 分子複合体パラ選択性

项目摘要

Development of new method for the selective synthesis of valuable chemicals in industry is quite important from the viewpoints of ecology, resource, energy, and so on. Previously we reported that cyclodextrins, cyclic oligomers of glucose, are highly effective for the selective organic synthesis. Various fine chemicals were synthesized in almost 100 % selectivities and in high yields. However, the reactions catalyzed by cyclodextrins are rather limited, since the hydroxyl residues are only the catalytic ones available. Still better catalysts should be obtained if appropriate functional residues are introduced to cyclodextrins by chemical modification.Here we succeeded in the selective synthesis of 4-(hydroxymethyl)phenol from phenol and formaldehyde and of 4-(hydroxyethyl)phenol from phenol and acetaldehyde, by use of various modified cyclodextrins. The structures of the molecular complexes, formed in these reaction mixtures, are determined by NMR spectroscopy. The hydroxyl residue introduced by the chemical modification to the primary hydroxyl side of the cavity form hydrogen bond with the formaldehyde, resulting in the activation of the formaldehyde for the reaction. In addition, the formaldehyde is fixed in the vicinity of the papa-carbon of the phenol by the hydrogen bonding, and thus the electrophilic attack by the formaldehyde selectively proceeds at the para-carbon. Potentialities of the modified cyclodextrins as practical catalysts are strongly indicated.

从生态，资源，能源等的角度来看，开发新方法来选择性合成有价值的化学物质在行业中非常重要。以前，我们报道了葡萄糖的环状酸性低聚物的环糊精对于选择性有机合成非常有效。各种精细化学物质以几乎100％的选择性和高产量合成。然而，由于羟基残基只是可用的催化反应，因此环糊精催化的反应相当有限。如果通过化学修饰将适当的功能残基引入到环糊精的情况下，则应获得更好的催化剂。在这里，我们成功地合成了来自酚类和乙醇的4-（羟基甲醇和甲醛）的4-（羟甲基）苯酚，并通过各种Modclied cyclied Cyclied Cyclied Cyclied Cyclodectin。在这些反应混合物中形成的分子复合物的结构由NMR光谱法确定。化学修饰引入的羟基残基向腔的一羟基侧与甲醛形成氢键，从而导致甲醛激活反应。另外，甲醛通过氢键固定在苯酚帕帕碳的附近，因此在para碳中选择性地进行甲醛的亲电攻击。强烈指出了修饰的环糊精的潜力。