Studies On The Synthesis Of 1,2,3-Triazoles Through One-pot Reactions

1,2,3-Triazoles has been emphasized as one of the most important heterocyclic compounds based on the vast studies. They own many interesting bioactivities, such as anti-allergy, anti-HIV, anti-cancer and so on. In addition, they have been applied widly in in various research fields, including biological science, material chemistry, medicinal chemistry, and synthetic organic chemistry. This paper consists of the following three parts, it mainly reviews the methodologies of synthesizing 1,2,3-triazoles in detail and summarizes my work.The first part is to review the methods of synthesizing 1,2,3-triazoles according to the positions of the substituted groups. Chemists have taken great attention on 1,2,3-triazoles because of their special structures and important pharmacological activities. By now, many ways have been developed for the synthesis of 1,2,3-triazoles, but there are not any reports that the 1,2,3-triazoles compounds are isolated from natural products. Kind of methods are summarized in this part.We introduce a novel way of synthesizing 4,5-disubstitued-1,2,3-triazoles in the second part. We performed PdCl2(PPh3)2/CuI catalyzed and ultrasonic promoted Sonogashira coupling of terminal acetylene and acide chloride first, which produce the internal yones, then sodium azide is added to react with yones to construct the corresponding 4,5-disubstitued-1,2,3-triazoles. Various 4,5-disubstituted-N-unsubstituted 1,2,3-triazoles can made easily from cheap and easily available starting materials terminal acetylene, acide chloride and sodium azide with excellent yields, and 2,4,5-trisubstituted-1,2,3-triazoles can be synthesized through the coupling reactions of 4,5-disubstitued-1,2,3-triazoles and aryl chrolides in high regioselectivities.A new method of regioselectively synthesizing 2,4,5-trisubstituted-1,2,3-triaz-oles is reported in the third part.2,4,5-trisubstituted-1,2,3-triazoles are regioselectively synthesized via two-step reaction of simple raw materials interminal ynones, sodium azide and alkyl halides in one pot. The reaction of interminal ynones and sodium azide produce the sodium salt of 4,5-disubstitued 1,2,3-triazoles, then the sodium salt of 4,5-disubstitued 1,2,3-triazoles can react directly with alkyl halides without adding any bases to produce 2,4,5-trisubstituted-1,2,3-triazoles in high regioselectivities. The procedure is efficient, convenient, environmentally friendly and atom-economical.