β-环糊精选择性催化氧化对甲氧基苯甲醛的研究  

Selective Catalytic Oxidation of p-Methoxybenzaldehyde in the Presence of β-Cyclodextrin

作　　者：纪红兵[1] 黄丽泉[1] 吴犇[1] 

机构地区：[1]华南理工大学化学与化工学院传热强化与过程节能教育部重点实验室,广州510640

出　　处：《化学学报》2009年第9期910-916,共7页Acta Chimica Sinica

基　　金：国家自然科学基金(No.20776053);新世纪优秀人才支持计划(No.NCET-06-740)资助项目

摘　　要：β-环糊精不仅有增溶作用,还具有由羟基与反应底物的相互作用所产生的催化作用,以及由此产生的β-环糊精与反应底物的相互作用对于反应选择性的影响.在β-环糊精存在下,以H2O2/H3BO3/H2SO4组成的反应体系,以水为唯一溶剂,对甲氧基苯甲醛通过Baeyer-Villiger氧化得到对甲氧基苯酚.β-环糊精可与对甲氧基苯甲醛和对甲氧基苯酚形成包结物,使反应速率降低,有效地保护甲氧基,防止其继续反应,提高反应的选择性.采用1HNMR,UV-Vis,FT-IR对β-环糊精与对甲氧基苯甲醛的相互作用进行表征分析,发现在水相中β-环糊精与对甲氧基苯甲醛可以自发地形成物质的量比为1∶1的包结物,其吉布斯函变△γGm(298K)为-14.577kJ·mol-1,稳定常数Ka为358,结合FT-IR分析推测出包结物中醛基较多地位于β-环糊精空腔的小口端.β-Cyclodextrin can solubilize the reactants, bind substrates selectively and catalyze chemical reactions by the interaction between β-cyclodextrin and substrates. During selective oxidation of p-methoxybenzaldehyde to p-methoxyphenol under supramolecular catalysis with β-cyclodextrin using H2O2/H3BO3/H2SO4 in water, β-cyclodextrin could form inclusion complexes with p-methoxybenzaldehyde and p-methoxyphenol, which effectively prevented them from continuous reaction and promoted the reaction selectivity. Various characterization methods including ^1H NMR, UV-Vis and FT-IR were adopted to analyze the interaction between β-cyclodextrin and p-methoxybenzaldehyde, showing that the stable inclusion of β-cyclodextrin and p-methoxybenzaldehyde with a molar ratio of 1 ： 1 can be automatically formed in water, with the stability constant of the inclusion, Ka, being 358 and the standard Gibbs function of molar reaction, △γ＇G^⊙m （298.15 K）, being -14.577 kJ·mol^-1. FT-IR analysis exhibits that aldehyde groups were mainly in the narrow mouth of the β-cvclodextrin in the inclusion comolexes.

关 键 词：Β-环糊精 对甲氧基苯甲醛 对甲氧基苯酚 包结物 

分 类 号：TQ244.1[化学工程—有机化工]