Chiral cinchona alkaloid-squaramide catalyst (CSF-MSNs) loaded on inorganic meso-porous silicon and preparation thereof

Abstract

The invention discloses a chiral cinchona alkaloid-squaramide catalyst (CSF-MSNs) loaded on an inorganic meso-porous silicon material and a synthesis method thereof. A chiral squaramide homogeneous catalyst of cinchona alkaloid and a sulfydryl functional carrier SH-MSNs are respectively synthesized, and then, a heterogeneous catalyst (CSF-MSNs) is made by a click chemistry method through the click bonding of sulfydryls on the material and double bonds in squaramide. The catalyst has the advantages that (1), the heterogeneous catalyst can be recycled and reused by a centrifuge method after finishing reaction and still has strong activity after being recycled for ten times; (2), the preparation of the sulfydryl functional material (SH-MSNs) is simpler and low in cost, and the sulfydryl functional material (SH-MSNs) can be further used for the immobilization of various chiral cinchona derivative catalysts; (3) the chiral cinchona alkaloid-squaramide catalyst has high thermodynamic stability, shows rich sulfydryls and can be further modified.

Description

technical field [0001] The invention belongs to the technical field of catalysts, and relates to a cinchona chiral square amide catalyst (CSF-MSNs) supported by inorganic mesoporous silicon and its preparation. Background technique [0002] The chiral square amide catalyst of cinchona base, as an important organic small molecule catalyst for building carbon-carbon bonds, has been widely used in various asymmetric catalytic reactions recently. In 2012, Stephen J.Connon et al. used this kind of catalyst to complete the asymmetric Aldol reaction of acid anhydride and aldehyde, and obtained the experimental results of high yield, high ee value, and high dr value; Da-Ming Du et al. used this kind of catalyst to catalyze The 1,4 addition reaction of nitromethane and enone obtained the highest ee value of 96%; Pengfei Xu et al. used a chiral square amide catalyst with 1 mol% cinchona base to catalyze chalcone and thianol The tandem reaction of three chiral centers has been synthes...

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Problems solved by technology

[0003] However, since the synthesis process of the chiral squaramide catalyst of cinchona base is relatively complicated and expensive, the recovery of the catalyst has certain practical significance.

In order to solve the widespread defects in homogeneous catalysis, such as difficult product separation, difficult catalyst recovery and environmental pollution, the majority of chemists have focused on heterogeneous catalysis (Guohua Liu et al, Adv.Synth.Catal.2012, 354, 3250–3258; Miquel A. Pericas et al, Org. Lett., 2013, 15, 3498–3501)

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