Preparation method of N-heteroaryl carbazole compounds

Abstract

The invention relates to a preparation method of N-heteroaryl carbazole compounds. The method comprises the following steps: by using carbazole compounds and heteroaryl halides as raw materials, Cu (I) salt as a catalyst and 1-methylimidazole as a ligand, carrying out reaction in an organic solvent at 110-130 DEG C in a nitrogen protective atmosphere in the presence of an alkaline matter tert-butyl alcohol lithium for 1.2 hours-5.0 days; and after the reaction finishes, carrying out separation purification on the reaction mixture to obtain the N-heteroaryl carbazole compounds disclosed as Formula (I), Formula (II) or Formula (III), wherein the heteroaryl halides are heteroaryl bromides or heteroaryl iodides. The method has the advantages of low raw material price, simple reaction technique and operation and high yield (up to 90% or above), is suitable for mass preparation and industrialization, and has wide application prospects.

Description

technical field [0001] The invention relates to a preparation method of N-heteroarylcarbazole compounds. Background technique [0002] N-heteroaryl carbazoles are an important class of organic functional materials, which are widely used in the field of organic electroluminescent materials (OLED). Due to their good thermal stability, electrochemical stability and electrical conductivity, these compounds are important components of organic phosphorescent materials. They can not only be used as auxiliary groups of phosphorescent molecules, but also as luminescent groups in specific molecular structures. Groups, which are widely present in the four-dentate ring metal platinum and palladium complex phosphorescent materials developed in recent years (Angew.Chem.Int.Ed.2013,52,6753; Org.Electronics,2014,15,1862; Adv. Mater. 2014, 26, 7116; ACS Appl. Mater. & Interfaces, 2015, 7, 16240; Adv. Optical Mater. 2015, 3, 390; Adv. Mater. 2015, 27, 2533). Secondly, the N-heteroaryl carba...

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Problems solved by technology

This type of reaction generally uses copper iodide (CuI) as a catalyst, and the amount of catalyst used in many reactions is generally large, 10% or more; experimental studies have found that ligands play a very important role in the reaction, and for different types of substrates , it is necessary to select an appropriate ligand to make the reaction go smoothly to obtain a good yield; the ligands used are generally dinitrogen, nitrogen oxide and dioxygen ligands, such as trans-cyclohexanediamine, trans-N , N-dimethylcyclohexanediamine, 1,10-phenanthroline and its derivatives, amino acid compounds, o-dicarbonyl compounds, etc. Some of the ligands with good catalytic performance are more expensive or require laboratory Synthesis, not conducive to the application of mass preparation (Nature Protocols 2007,2,2474; Chem.Sci.2010,1,13; J.Am.Chem.Soc.2015,137,11942)

At present, there is no systematic research report on the coupling of carbazole compounds and 2-bromopyridine compounds.

In 2011, Professor Yum from South Korea reported the microwave-promoted coupling reaction of carbazole and 2-bromopyridine under the catalysis of 10% CuI in the literature Tetrahedron2011, 67, 4820, but the reaction temperature was as high as 220°C, and more expensive Cs 2 CO 3 In addition, the microwave reaction is not conducive to the large-scale preparation of the product; in the same year, Bull.Korean.Chem.Soc.2011, 32, 2461 reported that this reaction can also be carried out at 150°C under the promotion of LiCl, but the reaction yield is only 74%. And the promotion mechanism of LiCl is still unclear

[0004] In summary, although there are reports about the synthetic methods in the preparation of N-heteroarylcarbazole compounds, there is no systematic synthesis research report on such compounds, and the use of noble metal catalysts, long reaction times, However, the yield is low and it is difficult to prepare in large quantities, so how to design a cheap, simple and efficient method for synthesizing such compounds is very necessary

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