Fujita Takeshi, Takeishi Masafumi, Ichikawa Junji
Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan.
Org Lett. 2020 Dec 4;22(23):9253-9257. doi: 10.1021/acs.orglett.0c03476. Epub 2020 Nov 23.
The copper-catalyzed [3 + 2] annulation of organic azides with (2,2-difluorovinyl)zinc chloride-TMEDA was achieved via C-F bond cleavage. Thus, a series of 1-substituted 4-fluorotriazoles was synthesized in high yields. In this reaction, the difluorovinylzinc complex functions as an easy-to-handle equivalent of fluoroacetylene (FC≡CH) to undergo cycloaddition with azides. This work offers a facile and practical method for the use of fluoroacetylene, which has been considered to be highly reactive and difficult to handle and control for synthetic applications.
