Facile Stereoselective Synthesis of (E)-1-Arylseleno-Substituted 1,3-Enynes and Their Applications in Synthesis of (E)-Enediynes

Abstract

(E)-1-Iodo-2-arylselenoethylenes 1 underwent the Sonogashira coupling reactions with terminal alkynes 2 to afford (E)-1-arylseleno-substituted 1,3-enynes 3 in high yields. (E)-1-Arylseleno-substituted 1,3-enynes 3 were coupled with alkynylmagnesium bromides 4 in the presence of a catalytic amount of NiCl₂(PPh₃)₂ to give stereoselectively (E)-enediynes 5 in good yields.

Keywords:

• (E)-1-Arylseleno-substituted 1,3-enyne
• (E)-enediyne
• nickel catalysis
• Sonogashira coupling
• stereoselective synthesis

ACKNOWLEDGMENT

We thank the Natural Science Foundation of Jiangxi Province in China (2007GZW0172) for financial support.

Notes

^a The reactions were performed with 1.0 mmol of 1, 1.5 mmol of 2, 0.05 mmol of Pd(PPh₃)₄, and 0.1 mmol of CuI in 3 mL of piperidine at room temperature.

^b Isolated yield based on 1 used.

^a The reactions were performed with 1.0 mmol of 3, 2.5 mmol of 4, and 0.03 mmol of NiCl₂(PPh₃)₂ in 12 mL of Et₂O at reflux temperature.

^b Isolated yield based on 3 used.