A metal-, azide- and CF3-reagent free approach for the synthesis of 5-trifluoromethyl-1,2,3-triazoles via base-mediated cascade annulation of diazo compounds with trifluoroacetimidoyl chlorides has been developed. Notable advantages of the reaction...

Herein, a facile and straightforward route to assemble 3-trifluoromethyl-1,2,4-triazoles via copper-mediated [3+2] cycloaddition of trifluoroacetimidoyl chlorides and N‑isocyanoiminotriphenylphosphorane (NIITP) has been described. Mo(CO)6 is utilized as an effective promotor to...

A straightforward strategy for the metal-free construction of trifluoromethyl-containing pyrazole derivatives has been achieved from readily available α-halo hydrazones and CF 3 -imidoyl sulfoxonium ylides. The cascade transformation proceeds through the formal [4+1] cycloaddition followed by an unexpected dual double bond isomerization. The protocol features mild conditions, easy operation, excellent substrate compatibility, and good regioselectivity. The synthetic utility is demonstrated by scale-up reaction and further elaboration of the obtained pyrazole products.A s one of the most ubiquitous five-membered N-heterocycles, pyrazole scaffolds have received considerable attention because of their broad spectrum of biological activities, which have been extensively applied in the fields of pharmaceuticals, agrochemicals, organic functional materials, and ligands. 1 Several commercially available drugs contain pyrazole fragments, such as celecoxib, rimonabant, lonazolac, acomplia, fluazolate, and insecticide fipronil (Figure 1). 1b,2 The pyrazole moiety is also used as a directing group for C−H bond functionalizations. 3 Therefore, the development of direct and efficient methods for preparing pyrazole compounds is highly desirable.