Cupric salt-containing catalyst system and application thereof

Abstract

The invention belongs to the field of catalysts, and in particular relates to a palladium-free, amine-free and ligand-free copper catalyst system. The catalyst system can catalyze a Sonogashira reaction to prepare alkyne compounds. The catalyst system comprises cupric salt, potassium carbonate and a solvent dimethyl sulfoxide, wherein the molar ratio of the cupric salt to the potassium carbonate is 1:20-40; and the cupric salt is one or the mixture of more than one of copper acetate, copper acetylacetonate, copper trifluoromethanesulfonate and copper sulfate. In the catalyst system, noble metal is replaced by the stable cupric salt, so that the catalyst system is economic, cheap and non-toxic; for a substrate with poor activity, the catalyst system is added with TBAB to promote the reaction remarkably; and the catalyst system is suitable for large-scale application and industrialized production.

Description

technical field [0001] The invention belongs to the field of catalysts, and in particular relates to a palladium-free, amine-free, and ligand-free copper catalyst system, which can catalyze the acetylenic compound by catalyzed head coupling reaction. Background technique [0002] The cross-coupling reaction between terminal alkynes and sp2-type carbon halides (aryl halohydrocarbons) catalyzed by Pd / Cu mixed catalysts is usually called Sonogashira coupling reaction. This reaction was first discovered independently by Heck, Cassar, and Sonogashira in 1975. After nearly three decades of development, it has gradually become well-known and has become an important name reaction. At present, the Sonogashira reaction has been widely used in the synthesis of substituted alkynes and large conjugated alkynes, and is considered to be the most effective and direct method for the synthesis of alkyne compounds. plays a key role in the synthesis of materials as well as nanomolecular device...

AI Technical Summary

Problems solved by technology

However, there are the following problems in the use of this type of catalyst: 1. palladium is expensive, so the cost is higher; 2. metal palladium has strong toxicity; 3. phosphorus-containing ligands are unstable, difficult to preserve, and easily oxidized; , thus affecting its application in drug synthesis and other occasions; ⑤ this reaction usually has high reactivity for bromo, iodoalkenes and aromatic hydrocarbons, but for chlorinated compounds, its reactivity is often very low, Although so far, this compound can also obtain the expected coupling product under some conditions, but there are still many limitations, so overcoming this limitation is also an urgent problem in this field.

However, the preparation of nano-copper clusters of a specific size is cumbersome and difficult, and its stability is poor, which is not suitable for large-scale application or industrial production; 2. Mao Jincheng's research group at Soochow University discovered an iron / copper composite catalyst system. It can also realize the Sonogashira reaction without ligand participation, and the specific catalyst system is 20mol% CuI and 20mol% Fe(acac) 3 , with potassium phosphate as the base, DMSO as the solvent, and the temperature is 140°C (see: Adv.Synth.Catal.2008, 350, 2477); 3. The Vogel research group in Switzerland also discovered the iron / copper composite catalyst system almost at the same time It can also catalyze the reaction without ligand participation. The specific catalyst system is 10mol% CuI and 10mol% Fe(acac) 3 , with cesium carbonate as the base, NMP (N-methylpyrrolidone) as the solvent, and the temperature is 140°C (see: Tetradedron Lett.2008, 49, 5961)

For reports 2 and 3, the stability of cuprous iodide used in the catalytic system is definitely not as good as that of divalent copper salts. In addition, another iron salt should be added, which increases the cost of the reaction.

4. Professor Li Jinheng from Hunan Normal University found that copper acetate can also catalyze the Sonogashira reaction without ligand participation (see: Chin.Chem.Lett.2007, 18, 13), but their catalyst system has the following shortcomings: (1) Copper acetate consumption is too big, is 50mol%; (2) reaction solvent requirement is higher, is triethylamine, and cost is high and smell is big; (3) and the selectivity of reaction is relatively poor, has alkyne self-coupling product to generate; ( 4) The reaction needs to be carried out at 140-150°C, and the yield for different substrates is not high