Studies On Friedel-Crafts Alkylation Reations Of Indoles Catalyzed By Zeolites

With awareness of environmental protection and "green chemistry" proposed, moreand more scholars are dedicating to develop new catalysts which will be benefit to both theenvironment and sustainable development of chemical industry. Friedel-Crafts alkylationreaction is one of the most important methods for the production of aromatic compounds.It’s carried out commercially using Lewis acids（AlCl3, MnCl2） or Bronsted acids（H₂SO₄,HF）. However, these traditional catalysts have limitations such as environmental pollution,reactor corrosion and difficulty in handling. In recent years, zeolite is being more and moreregarded as an environmentally friendly catalyst instead of traditional catalysts forFriedel-Crafts alkylation reaction.Friedel-Crafts alkylation reations of indole catalyzed by zeolites were studied on thispaper, including （1） Friedel-Crafts alkylation of indoles with benzyl alcohols （2）Ring-opening reactions of indoles with3,4-dihydropyran （3） Ring-opening reaction ofindoles with substituted dihydropyrans. First，beta zeolite was characterized by XRD, BET,NH3-TPD. Second, the effects of catalyst, solvent, reaction temperature and reaction timewere studied, an optimum condition was found out finally. The yield of majority reactionswas high, at the same time the applicability of reaction substrates was also very good.The results above indicated that the catalytic activity of zeolite for these kinds ofreactions was very high and as good as traditional catalysts, it can also be recycled in theory.It should be worth pointing out that using beta zeolite as catalyst for this series of indoleFriedel-Crafts alkylation reactions has not been reported, so it has some groundbreaking.