Stereoselective Synthesis of Difunctionalized 1,3-Dienes Containing Silicon and Selenium via Hydrozirconation of (Z)-3-(Trimethylsilyl)alk-3-en-1-ynes

Abstract

Sonogashira coupling of (E)-α-iodovinylsilanes 1 with (trimethylsilyl)-acetylene gave (Z)-1,3-bis(trimethylsilyl)alk-3-en-1-ynes 2, which underwent a desilylation reaction to afford (Z)-3-(trimethylsilyl)alk-3-en-1-ynes 3 in good yields. (1E,3Z)-1-Arylseleno-3-(trimethylsilyl)-substituted 1,3-dienes 5 could be synthesized stereoselectively via hydrozirconation of (Z)-3-(trimethylsilyl)alk-3-en-1-ynes 3, followed by trapping with arylselenenyl bromides.

Keywords:

• Difunctionalized 1,3-diene
• hydrozirconation
• (E)-α-iodovinylsilane
• Sonogashira coupling
• stereoselective synthesis

ACKNOWLEDGMENTS

We thank the National Natural Science Foundation of China (Project No. 20462002) and the Natural Science Foundation of Jiangxi Province (Project No. 2007GZW0172) for financial support.

Notes

^a The reaction of 1 (2 mmol) with (trimethylsilyl)acetylene (3 mmol) was carried out using Pd(PPh₃)₄ (0.1 mmol), CuI (0.2 mmol), and piperidine (6 mL) at room temperature for 2 h.

^b The desilylation reaction of 2 (1 mmol) with KF (10 mmol) was performed in methanol (4 mL) at 70°C for 5 h.

^c Isolated yield of 2 based on the 1 used.

^a Isolated yield based on the 3 used.