Mental-Free Synthesis Of 2-Aryl Benzoxazoles

Oxazole compounds are an important five-membered heterocyclic compound containing oxygen atoms and hydrogen atoms.The oxazole structure has weak basicity as well as weak aromaticity,and its skeleton is widely present in many natural products and living organisms.Its biological activity plays an indispensable role in biology,agriculture,medicine and functional materials.The first part,we have mainly introduced the application of oxazole compounds and their derivatives,and summarized the methods for the synthesis of oxazole proposed in recent decades,and the synthesis methods was classified according to the different types of catalysts.The second part is a detailed introduction of the method to synthesis benzoxazole without metal catalysis developed by our research group.As a simple and readily available compound,nitrone compounds can be obtained by reacting nitrobenzene with benzaldehyde.We have proposed a nitrone compounds as reaction substrates,potassium persulfate as an oxidant,an efficient route for the synthesis of valuable benzoxazoles through the self-oxidation cyclization with N-O bond cleavage.The reaction system is simple,the atomic utilization rate is high,and no other acid,base and additives are involved,various functional groups are compatible with this green protocol which can be carried out on one-pot easily and a series of 2-phenylbenzoxazole compounds with different substituent groups are synthesized...