Regioselective Alkynylation of Allylic Phosphates with Alkynyl Copper Reagents

We developed an alkynylation of allylic phosphates with acetylenes in the presence of copper and magnesium salts. The reaction proceeded regioselectively to afford the corresponding 1,4-enynes. Furthermore, the functional group tolerance of this reaction was established. As an application, the 1,4-enyne intermediate involved in the synthesis of 13R,19S,20S-trihydroxydocosapentaenoic acid could be efficiently synthesized.

Automated summary

We developed a method for the alkynylation of allylic phosphates with acetylenes in the presence of copper and magnesium salts. The reaction showed regioselectivity to produce corresponding 1,4-enynes. The reaction also exhibited good tolerance towards functional groups. As an application, the synthesis of 1,4-enyne intermediate for 13R,19S,20S-trihydroxydocosapentaenoic acid was efficiently achieved.