Stereoselective Synthesis of (1Z,3E)-2-Ethoxycarbonyl-Substituted 1,3-Dienes via Stille Coupling of (E)-α-Stannyl-α,β-Unsaturated Esters with Alkenyl Halides

Abstract

Palladium-catalyzed hydrostannylation of alkynyl esters in benzene at room temperature gives stereoselectively (E)-α-stannyl-α,β-unsaturated esters 1 in good yields. (E)-α-Stannyl-α,β-unsaturated esters 1 are difunctional group reagents that undergo Stille coupling reactions with alkenyl halides 2 in the presence of Pd(PPh₃)₄ and CuI co-catalyst to afford stereoselectively (1Z,3E)-2-ethoxycarbonyl-substituted 1,3-dienes 3 in good yields.

Keywords:

• Alkynyl ester
• functionalized 1,3-diene
• hydrostannylation
• (E)-α-stannyl-α,β-unsaturated ester
• Stille coupling

ACKNOWLEDGMENTS

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

Notes

^a Isolated yield based on (E)-α-stannyl-α,β-unsaturated ester 1.