分子筛催化下二吲哚甲烷的合成.pdf

Classified Index:CODE: .: NO: 20091353A Dissertation for the Degree of Master of Engineering Synthesis of Bis(indolyl)methanes over Zeolites Candidate : Ma Zheng Supervisor : Prof. Bai Guoyi Academic Degree Applied for : Master of Engineering Specialty : Applied Chemistry University : Hebei University Date of Oral Examination : May, 2012 摘要Ⅰ摘要二吲哚甲烷及其衍生物是一类非常重要的吲哚衍生物,具有许多重要的生物活性。二吲哚甲烷的合成方法主要是在催化剂的作用下,通过吲哚与醛类反应而制得。目前,工业上主要使用传统的Lewis酸和质子酸作为催化剂。尽管它们价格便宜,但存在着污染环境、腐蚀设备和分离困难等缺点。因此,寻找廉价的、易回收重复使用的绿色催化剂已成为该类反应研究发展的趋势。近年来,沸石分子筛因具有高的催化活性和好的水热稳定性,越来越受到人们的关注。本文以苯甲醛和吲哚合成苯基二吲哚甲烷的反应为模型,在多种酸改性的分子筛催化剂的催化作用下,对二吲哚甲烷衍生物的合成进行了系统研究。通过NH3-TPD等表征结果研究了乳酸的改性作用,结果表明,乳酸的改性使Hβ分子筛催化剂的弱酸显著降低,但中强酸的酸量略有提高,说明适量的降低弱酸的酸量和增加中强酸的酸量有利于苯基二吲哚甲烷合成反应的进行。在最优条件下, %, %, %以上, %以上。另外,在二吲哚甲烷衍生物的合成中,我们还发现醛芳环上取代基的吸电效应和空间效应对反应都有所影响。同时,建立了以吲哚和苯甲醛为原料通过Friedel-Crafts反应连续法合成苯基二吲哚甲烷的新方法。通过XRD、BET、ICP、27Al MAS NMR、NH3-TPD和Py-IR等催化剂表征手段对反应中使用的分子筛催化剂进行系统的分析。结果显示经过柠檬酸改性的分子筛有明显的脱铝过程,特别是分子筛的表面脱铝更为显著,暴露了更多的活性中心,从而有利于苯基二吲哚甲烷的合成。柠檬酸改性后催化剂的Br?nsted酸(B酸)和Lewis酸(L酸)都有所下降,特别是L酸,这说明低B酸和L酸有助于此反应的进行。在最佳条件下, %, %,并且该催化剂可稳定地连续化使用100 h以上。关键词二吲哚甲烷合成分子筛酸改性稳定性Abstract IIAbstract Bis(indolyl)methanes, have attracted much interest in recent years due to their novel structures and important biological activities. They are usually obtained from Friedel-Crafts alkylation of indole with various aldehydes in the presence of either Lewis or protic acids. However, these traditional catalysts have limitations such as environmental pollution hazards arising from the disposal of potential toxic wastes and difficulties in their handling. Hence, there is still a need for an efficient catalyst for the synthesis of bis(indolyl)methanes. Zeolites, with the advantages of selective adsorption, high strength and thermal stability, are regarded as an optimum choice among all the solid acid catalysts in recent years. In our research,