Method for highly selective preparation of linear aldehyde by olefin two-phase hydroformylation based on phosphine functionalized polyether alkyl guanidine salt ionic liquid

Abstract

The invention relates to a method for highly selective preparation of linear aldehyde by olefin two-phase hydroformylation based on a phosphine functionalized polyether alkyl guanidine salt ionic liquid. The method adopts a two-phase catalytic system, the catalytic system is composed of the phosphine functionalized polyether alkyl guanidine salt ionic liquid, a polyether alkyl guanidine salt ionic liquid, a rhodium catalyst, a reaction substrate olefin and a reaction product aldehyde, liquid / liquid two-phase hydroformylation reaction is carried out under certain reaction temperature and synthesis gas pressure, simple two-phase separation is carried out at the end of the reaction to realize separation and circulation of the rhodium catalyst, the rhodium catalyst can be used repeatedly, and the catalytic activity and selectivity do not decrease significantly. The TOF value of the system reaches 300-3400h<-1>, and the catalytic cycle cumulative TON value reaches 30832.

Description

technical field [0001] The invention relates to the technical field of chemistry and chemical engineering, in particular to a method for preparing normal aldehyde with high selectivity by two-phase hydroformylation of olefins based on phosphine-functionalized polyether alkylguanidine salt ionic liquid. Background technique [0002] The rhodium-catalyzed hydroformylation of olefins is a typical atom-economical reaction, and it is also a carbonylation reaction with more reports in the literature. It has become an ideal method for the preparation of high-carbon aldehydes / alcohols. Homogeneous hydroformylation has the advantages of high catalytic activity, good selectivity and mild reaction conditions, but the separation and recycling of rhodium catalysts has been the focus of attention in the field of homogeneous catalysis for a long time. [0003] In recent years, the liquid / liquid two-phase catalytic system with ionic liquid as the catalyst carrier has developed very rapidly,...

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Problems solved by technology

Homogeneous hydroformylation has the advantages of high catalytic activity, good selectivity and mild reaction conditions, but for a long time, the separation and recycling of rhodium catalysts has been the focus of attention in the field of homogeneous catalysis

But this two-phase system still has the following problems: one is that a large amount of ionic liquid is required as the carrier of the Rh-TPPTS catalyst, and the mass ratio of the ionic liquid to the rhodium catalyst precursor reaches 1000:1; Due to the limitation of mass transfer resistance, the catalytic activity is not high, and the TOF value is only 10-200h -1 The third is that the regioselectivity of normal aldehyde is relatively poor, and the anisotropic ratio is only 2.0:1-2.4:1 (67-71% of normal aldehyde regioselectivity)

Under this system, the phosphine-functionalized ionic liquid not only has the characteristics of a phosphine ligand, can form a complex catalyst with rhodium, but also has the solvent performance of an ionic liquid, and can serve as a carrier for a rhodium catalyst, so there is no need to add a large amount of other ions liquid, which fundamentally solves the problem of high dosage of ionic liquids, and also minimizes the negative effect of ionic liquids in catalytic reactions; but the system has very poor regioselectivity of normal aldehydes (<80%)

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