Identification Of Amines With Fluorescent Probe Of Binaphthol Monoaldehyde Derivatives

Objective: Amines exist in a wide range of life activities and have very important biological and physiological activities.For example,proteins,nucleic acids and antibiotics are all complex derivatives of amines.Most drugs are also amines or amine derivatives such as acetaminophen,R-penicillamine,levodopa and the like.Due to its advantages of high sensitivity,good selectivity,real-time and low cost,molecular probes have been widely used in medicine and biological sciences,such as molecular fluorescence-based microscopy imaging,which has been applied to the diagnosis of cancer cells.At present,many chiral binaphthol molecular fluorescent probes have been widely used in the analysis and detection of amines.In this paper,binaphthol is used as a raw material to modify the structure of the existing fluorescent probe molecules to obtain more More universal or enantioselective fluorescent probe molecules.Methods: Using binaphthol and chloromethylpyridine hydrochloride as raw materials,a fluorescent probe of chiral binaphthol monoaldehyde derivative was obtained by a simple and efficient chemical synthesis method.The purpose of the recognition of achiral amine compounds is achieved by the interaction between the aldehyde groups in the probe molecules and the amino groups of the small molecule amines,or the fluorescence of the chiral amine compounds is achieved through the coordination with metal zinc ions Response and enantioselective recognition.Further use of UV-Vis,MS,NMR and other methods to study the fluorescence response and selective recognition mechanism.Results: According to the existing methods in literature,we successfully obtained target compounds 1-3 and 1-9.Through coordination of zinc ion,compound 1-3 has enantioselective recognition of chiral phenylalaninol and leucinol in dichloromethane,but its fluorescence intensity is low and its stability is poor.By comparing the fluorescence recognition of compounds 1-3 and 1-4,it was clarified that the pyridine nitrogen atom is involved in the interaction between host and guest.Through the coordination of zinc ions,compound(S)-1-9 can selectively recognize chiral phenylglycinol in dichloromethane and has a very high enantioselectivity.The aldehyde groups in compounds 2-3 and 2-4 were able to form a six-membered ring with 1,3-propanediamine so that the fluorescence intensity was markedly enhanced.Therefore,it was possible to selectively recognize 1,3-propanediamine,and we found that 1,3-propanediamine can be selectively recognized by all compounds that are structurally similar to 2-3 and 2-4.Conclusion:We have made some progress in the enantioselective recognition of the novel binaphthylol monoaldehydes derivatives 1-3 and 1-9 containing pyridine,of which compounds 1-3 are both phenylalaninol and leucinol Chiral amino alcohols have the role of enantioselective recognition,for the universal application of such small-molecule fluorescent probe has some significance.At present,although the compound(S)-1-9 can only specifically recognize L-phenylglycinol,its selectivity is very good(ef> 10).If the compound of(R)-1-9 and(S)1-9 on the L-/D-phenylglycinol fluorescence emission spectra were mirror symmetry,then 1-9 compounds will have a good prospect.By contrasting the mechanism of action of compounds 2-2,2-3,2-4 and 2-9 with 1,3-propanediamine,we found that aldehyde groups on binaphthol can occur with 1,3-propanediamine When the ortho-hydroxyl group is protected,the aldehyde group can form a six-membered ring simultaneously with the two amino groups of 1,3-propanediamine,which can significantly enhance the fluorescence intensity.When there is a bare hydroxyl group in the ortho-position,the formation of intermolecular hydrogen bonds disrupts this interaction,and the aldehyde groups interact with 1,3-propanediamine to form schiff bases and thus do not selectively recognize 1,3-propanediamine.