N2-substituted-1,2,3-triazole ligand auxiliary Cu (I) catalysts and applications thereof

Abstract

The invention relates to N2-substituted-1,2,3-triazole ligand auxiliary Cu (I) catalysts and applications thereof in reaction of azides and terminal alkynes. The catalysts comprise N2-substituted-1,2,3-triazole ligands and Cu(I) salts, wherein the molar ratio of N2-substituted-1,2,3-triazole ligands to Cu(I) salts is 1:0.5-1:3. The catalysts are advantaged in that the middle nitrogen on the ring of the N2-substituted-1,2,3-triazole ligand has lower electron cloud density than the other two nitrogens, the middle nitrogen is substituted by a nitrogen heterocyclic ring, and the ligand utilizes triazole nitrogen atom with high electron cloud density and other heterocyclic ring nitrogen atom as a ligand effectively, the coordination capability with monovalent copper ions is enhanced, and monovalent copper ions is stabilized. The synthesis is simple and the properties are stable. In the catalysis of monovalent copper ions to a cycloaddition reaction of terminal alkynes and azides, the catalyst dosage is small, the reaction conditions are mild, the product yield is high and the substrate adaptability is strong.

Description

technical field [0001] The present invention relates to a class of ligands, catalysts and applications thereof, in particular to a class of N2-substituted 1,2,3-triazole ligand-assisted Cu(I) catalysts and their use in the reaction between azide compounds and terminal alkynes application. Background technique [0002] The early synthesis of 1,2,3-triazoles was mainly based on the 1,3-dipolar Huisgen cycloaddition reaction of organic azides and terminal alkynes, but this reaction required an active group on the azide or alkyne group, At the same time, the reaction requires high temperature or high pressure, and the reaction time is long, the reaction selectivity is not high, and the yield is low, so the application of 1,2,3-triazole compounds is greatly limited. In 2002, Sharpless and Meldal respectively reported that Cu(I) can efficiently promote the Huisgen [3+2] cycloaddition reaction of terminal alkynes and azides, and this discovery promoted the click chemistry based on...

AI Technical Summary

Problems solved by technology

[0004] (2) Cu(0) is oxidized to produce Cu(I) to catalyze the synthesis of 1,2,3-triazole, that is, metal copper is reacted in some oxidants (CuSO 4 , FeCl 3 ) in the presence of Cu (I) catalytic reaction; but with metal copper and other catalytic systems compared with the need for a longer reaction time and a larger amount, which needs to improve the copper metal catalytic system

[0005] (3) Cu(I) salt catalyzes the synthesis of 1,2,3-triazole, that is, CuI, CuBr, CuCl, CuCN, CuOAc and other copper salts can be used for catalysis in a certain solvent system and can achieve good yields; However, Cu(I) salts are easily disproportionated or oxidized, and the reaction system catalyzed by Cu(I) salts requires the use of specific solvents and even the addition of alkalis, which limits its application.

At present, the research on the ligands used for Cu(I) catalysis is mainly based on polyamines, poly-1,2,3-triazole-substituted amines and other ligands with complex structures, which are not easy to synthesize and are limited in application.

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