Mn(III)-Salen catalyst as well as preparation method and application thereof

Abstract

The invention discloses a Mn(III)-Salen catalyst as well as a preparation method and application thereof. The method comprises the following steps: performing reaction on 5-bromo-3-tert-butyl salicylaldehyde and pyridine-4-boric acid as raw materials to generate pyridine salicylaldehyde derivatives; reacting the pyridine salicylaldehyde derivatives with ethylene diamine to synthesize a Salen ligand with a pyridine functional group; finally coordinating divalent manganese salt with the Salen ligand, oxidizing, evaporating an obtained reaction solution to dryness, washing by water and filtering to obtain the Mn(III)-Salen catalyst. According to the method, a reaction system is simple, a reagent is easily available and low in cost, a reaction product post-treatment process is simple, the product purity is high, and the obtained Mn(III)-Salen catalyst is stable to water and air and capable of catalyzing styrene, 4-tert-butyl styrene, indene, alpha-methyl styrene and the like in a manner of relatively high activity and selectivity to synthesize olefin epoxides.

Description

technical field [0001] The invention belongs to the technical field of catalysts, and in particular relates to a Mn(III)-Salen catalyst, a preparation method thereof, and an application of catalytic olefin epoxidation. Background technique [0002] Salen is the abbreviation of N,N-bis-(saliylaldehyde) ethylendiamine compound. The Salen metal complex is obtained by condensation reaction of salicylaldehyde derivative and diamine, and then complexed with different metal ions. The common synthetic route is as follows : [0003] . [0004] Salen metal complexes have the characteristics of simple synthetic route, low cost, easy preparation, and high yield. They can also change the structure of the Salen catalyst by adjusting the 3,5-position substituent. For example, the change of the electronic effect of the 5-position substituent can make Salen The ligand has an electron-donating or electron-accepting effect, and the 3-position substitution can endow the Salen ligand with a ...

AI Technical Summary

Problems solved by technology

Most of the existing catalytic systems have disadvantages such as difficulty in catalyst preparation, high preparation cost, large amount of catalyst, low catalytic activity or harsh reaction conditions.

For example: the price of the MTO catalyst developed in recent years is about 2000 yuan / gram, which is not only expensive, but also difficult to synthesize; Bayer Company applied for a patent (publication number is CN 1418129A) on gold-containing catalyst in my country in 2003. This method The catalytic cost is high, the substrate applicability is not wide, and the catalytic performance is not good; the patent CN 1934115A uses a metal porphyrin catalyst, which is difficult to synthesize and separate; the patent CN 1023804174A reports a Ni-Salen complex as a subunit self-supporting catalysts, the synthesis steps of the catalyst are cumbersome, the catalytic activity is not high, and the product selectivity is not good, etc.