Synthetic method of visible light catalytic 2-imine thiazoline derivatives

Abstract

The invention relates to a synthetic method of visible light catalytic 2-imine thiazoline derivatives. The synthetic method comprises: in a reaction solvent, by using saturated aziridine as shown in a formula (II) and an isothiocyanate compound as shown in a formula (III) as raw materials, under the conditions of nitrogen protection and lighting and under the action of a photocatalyst and an oxidizing agent, performing a reaction to obtain the 2-imine thiazoline derivatives as shown in a formula (I); the photocatalyst is selected from any one of the followings: Ru(bpy)3(BF4)2, Ru(bpy)3Cl2.6H2O, Ru(bpy)3(PF6)2, Ir(ppy)3, [Ir(ppy)2bpy]BF4, [Ir(ppy)2bpy]PF6, Ru(bpz)3(PF6)2, Ir[dF(CF3)ppy]2(dtbbpy)PF6 and eosinY; the oxidizing agent is selected from any one of the followings: phenyl diazonium tetrafluoroborate, ceric ammonium nitrate, 1-(chloromethyl)-4-fluoro-1,4-diazoniabicyclo2.2.2octane bis(tetra fluoroborate). The method disclosed by the invention has the advantages of mild reaction condition, wide substrate range, greenness, environmental-friendliness, high atom economy, step economy and the like. The formulas are shown in the description.

Description

[0001] (1) Technical field [0002] The invention relates to a synthesis method of 2-iminothiazoline derivatives catalyzed by visible light. [0003] (2) Background technology [0004] Nitrogen-containing heterocyclic compounds have always attracted the attention of chemists because of their broad-spectrum biological activities, such as insecticidal, antibacterial, antiviral, anti-inflammatory, and anti-tumor. Since the 1970s, the research on thiazoline heterocyclic compounds has become increasingly active, and due to their unique structural characteristics, they have been used in a series of pesticides and medicines. As we all know, 2-iminothiazolines and their derivatives are an important class of pharmaceutical and chemical intermediates, widely used in the synthesis of natural products, and their application in the biopharmaceutical industry has also received more and more attention in recent years. 2-iminothiazolines are the core structures of some biologically and medica...

AI Technical Summary

Problems solved by technology

[0006] At present, the main synthetic methods mainly include: (1) intramolecular cyclization of N-(hydroxyalkyl) thiourea derivatives [(a) J.Am.Chem.Soc.1934,56,719.(b) Tetrahedron Lett.1999 , 40,3125.(c)Tetrahedron.2001,57,7137.], the reaction route is under the reaction conditions of strong acid (concentrated hydrochloric acid), organic phosphine compound (Lewis acid) or strong base (sodium hydroxide), After multi-step reaction, and the reaction temperature is high, the selectivity is low, and the yield is moderate; (2) the cyclization of thiourea and its derivatives and 1,2-dihaloalkyl, the reaction time is as long as more than 65 hours, and the raw material The preparation is complicated, the reaction temperature is high, and the scope of the substrate is small [J.Org.Chem.1961, 26, 4110.]; (3) The reaction of 2-amino-2-dihydrothiazole and an electrophile, the electrophile is generally selected Heteropolyenes such as isothiocyanate and isocyanate react at low temperature, and thiazolines are easily isomerized into 2-iminothiazolidines [(a)Chem.Abstr.1977,87,135171.(b)J.Org .Chem.1986,51,1910.(c)J.Phys.Chem.1970,74,769.]; (4) [3+2 ] Cycloaddition reaction, the reaction generally requires anhydrous and oxygen-free, transition metal catalyzed its cost is high [(a) J.Org.Chem.1972,37,4401.(b) J.Am.Chem.Soc.1958 ,80,3458.(c)J.Am.Chem.Soc.1995,117,4700.]; (5) the cyclization reaction of β-halogenated amine and isothiocyanate and thiocyanate, the reaction in Strong alkaline environment, long reaction time, benzene as a solvent, high toxicity, low reaction selectivity, narrow substrate range, serious pollution [(a) J.Heterocycl.Chem.1997,34,157.(b)TetrahedronAsymm.1997,8 ,3903.]

To sum up: these reactions need to be catalyzed by strong acids, strong bases, Lewis acids, transition metals or small organic molecules. The reaction conditions are often harsh, the cost is high, the reaction time is long, the selectivity is medium, and the environmental pollution is serious.

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