A Convenient Procedure for Sonogashira Reactions Using Propyne

Abstract

A modified Sonogashira coupling of aryl iodides and propyne was achieved using only two equivalents of propyne in THF from -78°C to room temperature.

Cu(II)-Catalyzed Aminocyclization of N-Propargyl Hydrazones to Substituted Pyrazolines

“…Finally, in order to demonstrate the applicability of this reaction methodology for synthesizing bioactive compounds, the progesterone receptor antagonist C, as shown in Figure 1, 64 was synthesized by using our newly developed reaction protocol (Scheme 6). In the synthetic route, initially, propargyl alcohol 6 was coupled with aryl iodide 7 via the Sonogashira coupling reaction 65 to afford coupling product 8, which under Mitsunobu reaction conditions 66 reacted with hydrazone 9 to obtain N-propargyl hydrazone 1w. As expected, under the optimized reaction conditions (Table 1, entry 6), N-propargyl hydrazone 1w readily afforded the bioactive compound C in 81% isolated yield.…”

“…The coupling reaction was performed following the previous literature to get the coupling product 8 in 90% isolated yield (0.97 g, 4.5 mmol).…”

“…Synthesis of Progesterone Receptor Antagonist C. Experimental Procedure for the Sonogashira Coupling Reaction of Propargyl Alcohol 6 with Aryl Iodide 7. The coupling reaction was performed following the previous literature 65 to get the coupling product 8 in 90% isolated yield (0.97 g, 4.5 mmol).…”